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revision 1.1.2.9, Thu May 22 22:17:44 2003 UTC revision 1.3, Thu Jun 10 18:13:42 2004 UTC
# Line 1  Line 1 
1  /******************************************************************************  /******************************************************************************
2   *   *
3   * XviD Bit Rate Controller Library   * XviD Bit Rate Controller Library
4   * - VBR 2 pass bitrate controler implementation -   *  - VBR 2 pass bitrate controller implementation -
5   *   *
6   * Copyright (C)      2002 Foxer <email?>   * Copyright (C)      2002 Foxer <email?>
7   *                    2002 Dirk Knop <dknop@gwdg.de>   *                    2002 Dirk Knop <dknop@gwdg.de>
# Line 29  Line 29 
29   *   *
30   *****************************************************************************/   *****************************************************************************/
31    
32    #define BQUANT_PRESCALE
33    #undef COMPENSATE_FORMULA
34    
35    /* forces second pass not to be bigger than first */
36    #undef PASS_SMALLER
37    
38    /* automtically alters overflow controls (strength and improvement/degradation)
39            to fight most common problems without user's knowladge */
40    #define SMART_OVERFLOW_SETTING
41    
42  #include <stdio.h>  #include <stdio.h>
43  #include <math.h>  #include <math.h>
44  #include <limits.h>  #include <limits.h>
45    
 #define RAD2DEG 57.295779513082320876798154814105  
 #define DEG2RAD 0.017453292519943295769236907684886  
   
46  #include "../xvid.h"  #include "../xvid.h"
47  #include "../image/image.h"  #include "../image/image.h"
48    
49    /*****************************************************************************
50     * Some default settings
51     ****************************************************************************/
52    
53    #define DEFAULT_KEYFRAME_BOOST 0
54    #define DEFAULT_OVERFLOW_CONTROL_STRENGTH 10
55    #define DEFAULT_CURVE_COMPRESSION_HIGH 0
56    #define DEFAULT_CURVE_COMPRESSION_LOW 0
57    #define DEFAULT_MAX_OVERFLOW_IMPROVEMENT 10
58    #define DEFAULT_MAX_OVERFLOW_DEGRADATION 10
59    
60    /* Keyframe settings */
61    #define DEFAULT_KFREDUCTION 20
62    #define DEFAULT_KFTHRESHOLD 1
63    
64    /*****************************************************************************
65     * Some default constants (can be tuned)
66     ****************************************************************************/
67    
68    /* Specify the invariant part of the headers bits (header+MV)
69     * as  hlength/cst */
70    #define INVARIANT_HEADER_PART_IVOP 1 /* factor 1.0f   */
71    #define INVARIANT_HEADER_PART_PVOP 2 /* factor 0.5f   */
72    #define INVARIANT_HEADER_PART_BVOP 8 /* factor 0.125f */
73    
74    /*****************************************************************************
75     * Structures
76     ****************************************************************************/
77    
78    /* Statistics */
79  typedef struct {  typedef struct {
80      int type;               /* first pass type */      int type;               /* first pass type */
81      int quant;              /* first pass quant */      int quant;              /* first pass quant */
82          int blks[3];                    /* k,m,y blks */          int blks[3];                    /* k,m,y blks */
83      int length;             /* first pass length */      int length;             /* first pass length */
84            int invariant;          /* what we assume as being invariant between the two passes, it's a sub part of header + MV bits */
85      int scaled_length;      /* scaled length */      int scaled_length;      /* scaled length */
86      int desired_length;     /* desired length; calcuated during encoding */          int desired_length;     /* desired length; calculated during encoding */
87            int error;
88    
89      int zone_mode;   /* XVID_ZONE_xxx */      int zone_mode;   /* XVID_ZONE_xxx */
90      double weight;      double weight;
91  } stat_t;  } twopass_stat_t;
   
   
   
92    
93  /* context struct */  /* Context struct */
94  typedef struct  typedef struct
95  {  {
96      xvid_plugin_2pass2_t param;      xvid_plugin_2pass2_t param;
97    
98      /* constant statistical data */          /*----------------------------------
99             * constant statistical data
100             *--------------------------------*/
101    
102            /* Number of frames of the sequence */
103          int num_frames;          int num_frames;
104    
105            /* Number of Intra frames of the sequence */
106      int num_keyframes;      int num_keyframes;
     uint64_t target;    /* target filesize */  
107    
108      int count[3];   /* count of each frame types */          /* Target filesize to reach */
109      uint64_t tot_length[3];  /* total length of each frame types */          uint64_t target;
     double avg_length[3];   /* avg */  
     int min_length[3];  /* min frame length of each frame types */  
     uint64_t tot_scaled_length[3];  /* total scaled length of each frame type */  
     int max_length;     /* max frame size */  
   
     /* zone statistical data */  
     double avg_weight;  /* average weight */  
     int64_t tot_quant;   /* total length used by XVID_ZONE_QUANT zones */  
   
   
     double curve_comp_scale;  
     double movie_curve;  
   
         double alt_curve_low;  
         double alt_curve_high;  
         double alt_curve_low_diff;  
         double alt_curve_high_diff;  
     double alt_curve_curve_bias_bonus;  
         double alt_curve_mid_qual;  
         double alt_curve_qual_dev;  
110    
111      /* dynamic */          /* Count of each frame types */
112            int count[3];
113    
114            /* Total length of each frame types (1st pass) */
115            uint64_t tot_length[3];
116            uint64_t tot_invariant[3];
117    
118            /* Average length of each frame types (used first for 1st pass data and
119             * then for scaled averages */
120            double avg_length[3];
121    
122            /* Minimum frame length allowed for each frame type */
123            int min_length[3];
124    
125            /* Total bytes per frame type once the curve has been scaled
126             * NB: advanced parameters do not change this value. This field
127             *     represents the total scaled w/o any advanced settings */
128            uint64_t tot_scaled_length[3];
129    
130            /* Maximum observed frame size observed during the first pass, the RC
131             * will try tp force all frame sizes in the second pass to be under that
132             * limit */
133            int max_length;
134    
135            /*----------------------------------
136             * Zones statistical data
137             *--------------------------------*/
138    
139            /* Total length used by XVID_ZONE_QUANT zones */
140            uint64_t tot_quant;
141            uint64_t tot_quant_invariant;
142    
143            /* Holds the total amount of frame bytes, zone weighted (only scalable
144             * part of frame bytes) */
145            uint64_t tot_weighted;
146    
147            /*----------------------------------
148             * Advanced settings helper ratios
149             *--------------------------------*/
150    
151            /* This the ratio that has to be applied to all p/b frames in order
152             * to reserve/retrieve bits for/from keyframe boosting and consecutive
153             * keyframe penalty */
154            double pb_iboost_tax_ratio;
155    
156            /* This the ratio to apply to all b/p frames in order to respect the
157             * assymetric curve compression while respecting a target filesize
158             * NB: The assymetric delta gain has to be computed before this ratio
159             *     is applied, and then the delta is added to the scaled size */
160            double assymetric_tax_ratio;
161    
162            /*----------------------------------
163             * Data from the stats file kept
164             * into RAM for easy access
165             *--------------------------------*/
166    
167            /* Array of keyframe locations
168             * eg: rc->keyframe_locations[100] returns the frame number of the 100th
169             *     keyframe */
170      int * keyframe_locations;      int * keyframe_locations;
     stat_t * stats;  
171    
172      double pquant_error[32];          /* Index of the last keyframe used in the keyframe_location */
173      double bquant_error[32];          int KF_idx;
174      int quant_count[32];  
175            /* Array of all 1st pass data file -- see the twopass_stat_t structure
176             * definition for more details */
177            twopass_stat_t * stats;
178    
179            /*----------------------------------
180             * Hysteresis helpers
181             *--------------------------------*/
182    
183            /* This field holds the int2float conversion errors of each quant per
184             * frame type, this allow the RC to keep track of rouding error and thus
185             * increase or decrease the chosen quant according to this residue */
186            double quant_error[3][32];
187    
188            /* This fields stores the count of each quant usage per frame type
189             * No real role but for debugging */
190            int quant_count[3][32];
191    
192            /* Last valid quantizer used per frame type, it allows quantizer
193             * increament/decreament limitation in order to avoid big image quality
194             * "jumps" */
195      int last_quant[3];      int last_quant[3];
196    
197      double curve_comp_error;          /*----------------------------------
198      int overflow;           * Overflow control
199      int KFoverflow;           *--------------------------------*/
200      int KFoverflow_partial;  
201      int KF_idx;          /* Current overflow that has to be distributed to p/b frames */
202            double overflow;
203    
204            /* Total overflow for keyframes -- not distributed directly */
205            double KFoverflow;
206    
207            /* Amount of keyframe overflow to introduce to the global p/b frame
208             * overflow counter at each encoded frame */
209            double KFoverflow_partial;
210    
211            /* Unknown ???
212             * ToDo: description */
213      double fq_error;      double fq_error;
 } rc_2pass2_t;  
214    
215            int min_quant; /* internal minimal quant, prevents wrong quants from being used */
216    
217            /*----------------------------------
218  #define BUF_SZ 1024           * Debug
219  #define MAX_COLS    5           *--------------------------------*/
220            double desired_total;
221            double real_total;
222    } rc_2pass2_t;
223    
224    
225  /* open stats file, and count num frames */  /*****************************************************************************
226     * Sub plugin functions prototypes
227     ****************************************************************************/
228    
229    static int rc_2pass2_create(xvid_plg_create_t * create, rc_2pass2_t ** handle);
230    static int rc_2pass2_before(rc_2pass2_t * rc, xvid_plg_data_t * data);
231    static int rc_2pass2_after(rc_2pass2_t * rc, xvid_plg_data_t * data);
232    static int rc_2pass2_destroy(rc_2pass2_t * rc, xvid_plg_destroy_t * destroy);
233    
234    /*****************************************************************************
235     * Plugin definition
236     ****************************************************************************/
237    
238  static int det_stats_length(rc_2pass2_t * rc, char * filename)  int
239    xvid_plugin_2pass2(void * handle, int opt, void * param1, void * param2)
240  {  {
241      FILE * f;          switch(opt) {
242      int n, ignore;          case XVID_PLG_INFO :
243      char type;          case XVID_PLG_FRAME :
   
     rc->num_frames = 0;  
     rc->num_keyframes = 0;  
   
     if ((f = fopen(filename, "rt")) == NULL)  
244          return 0;          return 0;
245    
246      while((n = fscanf(f, "%c %d %d %d %d %d %d\n",          case XVID_PLG_CREATE :
247          &type, &ignore, &ignore, &ignore, &ignore, &ignore, &ignore)) != EOF) {                  return rc_2pass2_create((xvid_plg_create_t*)param1, param2);
         if (type == 'i') {  
             rc->num_frames++;  
             rc->num_keyframes++;  
         }else if (type == 'p' || type == 'b' || type == 's') {  
             rc->num_frames++;  
         }  
     }  
248    
249      fclose(f);          case XVID_PLG_DESTROY :
250                    return rc_2pass2_destroy((rc_2pass2_t*)handle, (xvid_plg_destroy_t*)param1);
251    
252            case XVID_PLG_BEFORE :
253                    return rc_2pass2_before((rc_2pass2_t*)handle, (xvid_plg_data_t*)param1);
254    
255      return 1;          case XVID_PLG_AFTER :
256                    return rc_2pass2_after((rc_2pass2_t*)handle, (xvid_plg_data_t*)param1);
257  }  }
258    
259            return XVID_ERR_FAIL;
260    }
261    
262    /*****************************************************************************
263     * Sub plugin functions definitions
264     ****************************************************************************/
265    
266    /* First a few local helping function prototypes */
267    static  int statsfile_count_frames(rc_2pass2_t * rc, char * filename);
268    static  int statsfile_load(rc_2pass2_t *rc, char * filename);
269    static void zone_process(rc_2pass2_t *rc, const xvid_plg_create_t * create);
270    static void first_pass_stats_prepare_data(rc_2pass2_t * rc);
271    static void first_pass_scale_curve_internal(rc_2pass2_t *rc);
272    static void scaled_curve_apply_advanced_parameters(rc_2pass2_t * rc);
273    static  int check_curve_for_vbv_compliancy(rc_2pass2_t * rc, const float fps);
274    static  int scale_curve_for_vbv_compliancy(rc_2pass2_t * rc, const float fps);
275    #if 0
276    static void stats_print(rc_2pass2_t * rc);
277    #endif
278    
279  /* open stats file(s) and read into rc->stats array */  /*----------------------------------------------------------------------------
280     *--------------------------------------------------------------------------*/
281    
282  static int load_stats(rc_2pass2_t *rc, char * filename)  static int
283    rc_2pass2_create(xvid_plg_create_t * create, rc_2pass2_t **handle)
284  {  {
285      FILE * f;          xvid_plugin_2pass2_t * param = (xvid_plugin_2pass2_t *)create->param;
286      int i, not_scaled;          rc_2pass2_t * rc;
287            int i;
288    
289            rc = malloc(sizeof(rc_2pass2_t));
290            if (rc == NULL)
291                    return XVID_ERR_MEMORY;
292    
293      if ((f = fopen(filename, "rt"))==NULL)          rc->param = *param;
         return 0;  
294    
295      i = 0;          /* Initialize all defaults */
296          not_scaled = 0;  #define _INIT(a, b) if((a) <= 0) (a) = (b)
297      while(i < rc->num_frames) {          /* Let's set our defaults if needed */
298          stat_t * s = &rc->stats[i];          _INIT(rc->param.keyframe_boost, DEFAULT_KEYFRAME_BOOST);
299          int n;          _INIT(rc->param.overflow_control_strength, DEFAULT_OVERFLOW_CONTROL_STRENGTH);
300          char type;          _INIT(rc->param.curve_compression_high, DEFAULT_CURVE_COMPRESSION_HIGH);
301            _INIT(rc->param.curve_compression_low, DEFAULT_CURVE_COMPRESSION_LOW);
302            _INIT(rc->param.max_overflow_improvement, DEFAULT_MAX_OVERFLOW_IMPROVEMENT);
303            _INIT(rc->param.max_overflow_degradation,  DEFAULT_MAX_OVERFLOW_DEGRADATION);
304    
305            /* Keyframe settings */
306            _INIT(rc->param.kfreduction, DEFAULT_KFREDUCTION);
307            _INIT(rc->param.kfthreshold, DEFAULT_KFTHRESHOLD);
308    #undef _INIT
309    
310                  s->scaled_length = 0;          /* Initialize some stuff to zero */
311          n = fscanf(f, "%c %d %d %d %d %d %d\n", &type, &s->quant, &s->blks[0], &s->blks[1], &s->blks[2], &s->length, &s->scaled_length);          for(i=0; i<3; i++) {
312          if (n == EOF) break;                  int j;
313                  if (n < 7) {                  for (j=0; j<32; j++) {
314                          not_scaled = 1;                          rc->quant_error[i][j] = 0;
315                            rc->quant_count[i][j] = 0;
316                  }                  }
   
         if (type == 'i') {  
             s->type = XVID_TYPE_IVOP;  
         }else if (type == 'p' || type == 's') {  
             s->type = XVID_TYPE_PVOP;  
         }else if (type == 'b') {  
             s->type = XVID_TYPE_BVOP;  
         }else{  /* unknown type */  
             DPRINTF(XVID_DEBUG_RC, "unknown stats frame type; assuming pvop\n");  
             s->type = XVID_TYPE_PVOP;  
317          }          }
318    
319          i++;          for (i=0; i<3; i++) rc->last_quant[i] = 0;
320    
321            rc->fq_error = 0;
322            rc->min_quant = 1;
323    
324            /* Count frames (and intra frames) in the stats file, store the result into
325             * the rc structure */
326            if (statsfile_count_frames(rc, param->filename) == -1) {
327                    DPRINTF(XVID_DEBUG_RC,"[xvid rc] -- ERROR: fopen %s failed\n", param->filename);
328                    free(rc);
329                    return(XVID_ERR_FAIL);
330      }      }
331    
332      rc->num_frames = i;          /* Allocate the stats' memory */
333            if ((rc->stats = malloc(rc->num_frames * sizeof(twopass_stat_t))) == NULL) {
334                    free(rc);
335                    return(XVID_ERR_MEMORY);
336            }
337    
338          fclose(f);          /* Allocate keyframes location's memory
339             * PS: see comment in pre_process0 for the +1 location requirement */
340            rc->keyframe_locations = malloc((rc->num_keyframes + 1) * sizeof(int));
341            if (rc->keyframe_locations == NULL) {
342                    free(rc->stats);
343                    free(rc);
344                    return(XVID_ERR_MEMORY);
345            }
346    
347      return 1;          /* Load the first pass stats */
348            if (statsfile_load(rc, param->filename) == -1) {
349                    DPRINTF(XVID_DEBUG_RC,"[xvid rc] -- ERROR: fopen %s failed\n", param->filename);
350                    free(rc->keyframe_locations);
351                    free(rc->stats);
352                    free(rc);
353                    return XVID_ERR_FAIL;
354  }  }
355    
356            /* Compute the target filesize */
357            if (rc->param.bitrate<0) {
358                    /* if negative, bitrate equals the target (in kbytes) */
359                    rc->target = ((uint64_t)(-rc->param.bitrate)) * 1024;
360            } else if (rc->num_frames  < create->fbase/create->fincr) {
361                    /* Source sequence is less than 1s long, we do as if it was 1s long */
362                    rc->target = rc->param.bitrate / 8;
363            } else {
364                    /* Target filesize = bitrate/8 * numframes / framerate */
365                    rc->target =
366                            ((uint64_t)rc->param.bitrate * (uint64_t)rc->num_frames * \
367                             (uint64_t)create->fincr) / \
368                            ((uint64_t)create->fbase * 8);
369            }
370    
371            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Frame rate: %d/%d (%ffps)\n",
372                            create->fbase, create->fincr,
373                            (double)create->fbase/(double)create->fincr);
374            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Number of frames: %d\n", rc->num_frames);
375            if(rc->param.bitrate>=0)
376                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Target bitrate: %ld\n", rc->param.bitrate);
377            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Target filesize: %lld\n", rc->target);
378    
379            /* Compensate the average frame overhead caused by the container */
380            rc->target -= rc->num_frames*rc->param.container_frame_overhead;
381            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Container Frame overhead: %d\n", rc->param.container_frame_overhead);
382            if(rc->param.container_frame_overhead)
383                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- New target filesize after container compensation: %lld\n", rc->target);
384    
385  #if 0          /* When bitrate is not given it means it has been scaled by an external
386  static void print_stats(rc_2pass2_t * rc)           * application */
387  {          if (rc->param.bitrate) {
388      int i;                  /* Apply zone settings
389      DPRINTF(XVID_DEBUG_RC, "type quant length scaled_length\n");                   * - set rc->tot_quant which represents the total num of bytes spent in
390                     *   fixed quant zones
391                     * - set rc->tot_weighted which represents the total amount of bytes
392                     *   spent in normal or weighted zones in first pass (normal zones can
393                     *   be considered weight=1)
394                     * - set rc->tot_quant_invariant which represents the total num of bytes
395                     *   spent in fixed quant zones for headers */
396                    zone_process(rc, create);
397            } else {
398                    /* External scaling -- zones are ignored */
399          for (i = 0; i < rc->num_frames; i++) {          for (i = 0; i < rc->num_frames; i++) {
400          stat_t * s = &rc->stats[i];                          rc->stats[i].zone_mode = XVID_ZONE_WEIGHT;
401          DPRINTF(XVID_DEBUG_RC, "%d %d %d %d\n", s->type, s->quant, s->length, s->scaled_length);                          rc->stats[i].weight = 1.0;
402      }      }
403                    rc->tot_quant = 0;
404  }  }
 #endif  
405    
406  /* pre-process the statistics data          /* Gathers some information about first pass stats:
407      - for each type, count, tot_length, min_length, max_length           *  - finds the minimum frame length for each frame type during 1st pass.
408      - set keyframes_locations           *     rc->min_size[]
409             *  - determines the maximum frame length observed (no frame type distinction).
410             *     rc->max_size
411             *  - count how many times each frame type has been used.
412             *     rc->count[]
413             *  - total bytes used per frame type
414             *     rc->tot_length[]
415             *  - total bytes considered invariant between the 2 passes
416             *  - store keyframe location
417             *     rc->keyframe_locations[]
418  */  */
419            first_pass_stats_prepare_data(rc);
420    
421  static void          /* If we have a user bitrate, it means it's an internal curve scaling */
422  pre_process0(rc_2pass2_t * rc)          if (rc->param.bitrate) {
423  {                  /* Perform internal curve scaling */
424      int i,j;                  first_pass_scale_curve_internal(rc);
   
     for (i=0; i<3; i++) {  
         rc->count[i]=0;  
         rc->tot_length[i] = 0;  
         rc->last_quant[i] = 0;  
                 rc->min_length[i] = INT_MAX;  
425      }      }
426    
427          rc->max_length = INT_MIN;          /* Apply advanced curve options, and compute some parameters in order to
428             * shape the curve in the BEFORE/AFTER pair of functions */
429      for (i=j=0; i<rc->num_frames; i++) {          scaled_curve_apply_advanced_parameters(rc);
         stat_t * s = &rc->stats[i];  
430    
431          rc->count[s->type-1]++;  /* Check curve for VBV compliancy and rescale if necessary */
         rc->tot_length[s->type-1] += s->length;  
432    
433          if (s->length < rc->min_length[s->type-1]) {  #ifdef VBV_FORCE
434              rc->min_length[s->type-1] = s->length;    if (rc->param.vbv_size==0)
435      {
436        rc->param.vbv_size      =  3145728;
437        rc->param.vbv_initial   =  2359296;
438        rc->param.vbv_maxrate  =  4000000;
439        rc->param.vbv_peakrate = 10000000;
440          }          }
441    #endif
442    
443          if (s->length > rc->max_length) {    if (rc->param.vbv_size>0)    /* vbv_size==0 switches VBV check off */
444              rc->max_length = s->length;    {
445          }      const double fps = (double)create->fbase/(double)create->fincr;
446        int status = check_curve_for_vbv_compliancy(rc, fps);
447    #ifdef VBV_DEBUG
448        if (status)
449          fprintf(stderr,"underflow detected\n Scaling Curve for compliancy... ");
450    #endif
451    
452          if (s->type == XVID_TYPE_IVOP) {          status = scale_curve_for_vbv_compliancy(rc, fps);
453              rc->keyframe_locations[j] = i;  
454              j++;  #ifdef VBV_DEBUG
455          if (status==0)
456            fprintf(stderr,"done.\n");
457          else
458            fprintf(stderr,"impossible.\n");
459    #endif
460          }          }
461            *handle = rc;
462            return(0);
463      }      }
464    
465          /*  /*----------------------------------------------------------------------------
466           * The "per sequence" overflow system considers a natural sequence to be   *--------------------------------------------------------------------------*/
          * formed by all frames between two iframes, so if we want to make sure  
          * the system does not go nuts during last sequence, we force the last  
          * frame to appear in the keyframe locations array.  
          */  
     rc->keyframe_locations[j] = i;  
467    
468          DPRINTF(XVID_DEBUG_RC, "Min 1st pass IFrame length: %d\n", rc->min_length[0]);  static int
469          DPRINTF(XVID_DEBUG_RC, "Min 1st pass PFrame length: %d\n", rc->min_length[1]);  rc_2pass2_destroy(rc_2pass2_t * rc, xvid_plg_destroy_t * destroy)
470          DPRINTF(XVID_DEBUG_RC, "Min 1st pass BFrame length: %d\n", rc->min_length[2]);  {
471  }          DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- target_total:%lld desired_total:%.2f (%.2f%%) actual_total:%.2f (%.2f%%)\n",
472                            rc->target,
473                            rc->desired_total,
474                            100*rc->desired_total/(double)rc->target,
475                            rc->real_total,
476                            100*rc->real_total/(double)rc->target);
477    
478            free(rc->keyframe_locations);
479            free(rc->stats);
480            free(rc);
481            return(0);
482    }
483    
484  /* calculate zone weight "center" */  /*----------------------------------------------------------------------------
485     *--------------------------------------------------------------------------*/
486    
487  static void  static int
488  zone_process(rc_2pass2_t *rc, const xvid_plg_create_t * create)  rc_2pass2_before(rc_2pass2_t * rc, xvid_plg_data_t * data)
489  {  {
490      int i,j;          twopass_stat_t * s = &rc->stats[data->frame_num];
491      int n = 0;          double dbytes;
492            double scaled_quant;
493            double overflow;
494            int capped_to_max_framesize = 0;
495    
496      rc->avg_weight = 0.0;          /* This function is quite long but easy to understand. In order to simplify
497      rc->tot_quant = 0;           * the code path (a bit), we treat 3 cases that can return immediatly. */
498    
499            /* First case: Another plugin has already set a quantizer */
500            if (data->quant > 0)
501                    return(0);
502    
503      if (create->num_zones == 0) {          /* Second case: insufficent stats data
504          for (j = 0; j < rc->num_frames; j++) {           * We can't guess much what we should do, let core decide all alone */
505              rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;          if (data->frame_num >= rc->num_frames) {
506              rc->stats[j].weight = 1.0;                  DPRINTF(XVID_DEBUG_RC,"[xvid rc] -- stats file too short (now processing frame %d)",
507          }                          data->frame_num);
508          rc->avg_weight += rc->num_frames * 1.0;                  return(0);
         n += rc->num_frames;  
509      }      }
510    
511            /* Third case: We are in a Quant zone
512             * Quant zones must just ensure we use the same settings as first pass
513             * So set the quantizer and the type */
514            if (s->zone_mode == XVID_ZONE_QUANT) {
515                    /* Quant stuff */
516                    rc->fq_error += s->weight;
517                    data->quant = (int)rc->fq_error;
518                    rc->fq_error -= data->quant;
519    
520      for(i=0; i < create->num_zones; i++) {                  /* The type stuff */
521                    data->type = s->type;
522    
523          int next = (i+1<create->num_zones) ? create->zones[i+1].frame : rc->num_frames;                  /* The only required data for AFTER step is this one for the overflow
524                     * control */
525                    s->desired_length = s->length;
526    
527          if (i==0 && create->zones[i].frame > 0) {                  return(0);
             for (j = 0; j < create->zones[i].frame && j < rc->num_frames; j++) {  
                 rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;  
                 rc->stats[j].weight = 1.0;  
             }  
             rc->avg_weight += create->zones[i].frame * 1.0;  
             n += create->zones[i].frame;  
528          }          }
529    
         if (create->zones[i].mode == XVID_ZONE_WEIGHT) {  
             for (j = create->zones[i].frame; j < next && j < rc->num_frames; j++ ) {  
                 rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;  
                 rc->stats[j].weight = (double)create->zones[i].increment / (double)create->zones[i].base;  
             }  
             next -= create->zones[i].frame;  
             rc->avg_weight += (double)(next * create->zones[i].increment) / (double)create->zones[i].base;  
             n += next;  
         }else{  // XVID_ZONE_QUANT  
             for (j = create->zones[i].frame; j < next && j < rc->num_frames; j++ ) {  
                 rc->stats[j].zone_mode = XVID_ZONE_QUANT;  
                 rc->stats[j].weight = (double)create->zones[i].increment / (double)create->zones[i].base;  
                 rc->tot_quant += rc->stats[j].length;  
             }  
         }  
     }  
     rc->avg_weight = n>0 ? rc->avg_weight/n : 1.0;  
530    
531      DPRINTF(XVID_DEBUG_RC, "center_weight: %f (for %i frames);   fixed_bytes: %i\n", rc->avg_weight, n, rc->tot_quant);          /*************************************************************************/
532  }          /*************************************************************************/
533            /*************************************************************************/
534    
535            /*-------------------------------------------------------------------------
536             * Frame bit allocation first part
537             *
538             * First steps apply user settings, just like it is done in the theoritical
539             * scaled_curve_apply_advanced_parameters
540             *-----------------------------------------------------------------------*/
541    
542  /* scale the curve */          /* Set desired to what we are wanting to obtain for this frame */
543            dbytes = (double)s->scaled_length;
544    
545  static void          /* IFrame user settings*/
546  internal_scale(rc_2pass2_t *rc)          if (s->type == XVID_TYPE_IVOP) {
547  {                  /* Keyframe boosting -- All keyframes benefit from it */
548          int64_t target  = rc->target - rc->tot_quant;                  dbytes += dbytes*rc->param.keyframe_boost / 100;
         int64_t pass1_length = rc->tot_length[0] + rc->tot_length[1] + rc->tot_length[2] - rc->tot_quant;  
         int min_size[3];  
         double scaler;  
         int i;  
549    
550    #if 0 /* ToDo: decide how to apply kfthresholding */
551    #endif
552            } else {
553    
554          /*                  /* P/S/B frames must reserve some bits for iframe boosting */
555           * Perform an initial scale pass.                  dbytes *= rc->pb_iboost_tax_ratio;
          * if a frame size is scaled underneath our hardcoded minimums, then we  
          * force the frame size to the minimum, and deduct the original & scaled  
          * frame length from the original and target total lengths  
          */  
556    
557          min_size[0] = ((rc->stats[0].blks[0]*22) + 240) / 8;                  /* Apply assymetric curve compression */
558          min_size[1] = (rc->stats[0].blks[0] + 88) / 8;                  if (rc->param.curve_compression_high || rc->param.curve_compression_low) {
559          min_size[2] = 8;                          double assymetric_delta;
560    
561          scaler = (double)target / (double)pass1_length;                          /* Compute the assymetric delta, this is computed before applying
562                             * the tax, as done in the pre_process function */
563          if (target <= 0 || pass1_length <= 0 || target >= pass1_length) {                          if (dbytes > rc->avg_length[s->type-1])
564                  DPRINTF(XVID_DEBUG_RC, "undersize warning\n");                                  assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * rc->param.curve_compression_high / 100.0;
565          scaler = 1.0;                          else
566                                    assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * rc->param.curve_compression_low  / 100.0;
567    
568                            /* Now we must apply the assymetric tax, else our curve compression
569                             * would not give a theoritical target size equal to what it is
570                             * expected */
571                            dbytes *= rc->assymetric_tax_ratio;
572    
573                            /* Now we can add the assymetric delta */
574                            dbytes += assymetric_delta;
575                    }
576          }          }
577    
578      DPRINTF(XVID_DEBUG_RC,          /* That is what we would like to have -- Don't put that chunk after
579                          "Before any correction: target=%i, tot_length=%i, scaler=%f\n",           * overflow control, otherwise, overflow is counted twice and you obtain
580                          (int)target, (int)pass1_length, scaler);           * half sized bitrate sequences */
581            s->desired_length  = (int)dbytes;
582          for (i=0; i<rc->num_frames; i++) {          rc->desired_total += dbytes;
                 stat_t * s = &rc->stats[i];  
                 int len;  
583    
584          if (s->zone_mode == XVID_ZONE_QUANT) {          /*------------------------------------------------------------------------
585              s->scaled_length = s->length;           * Frame bit allocation: overflow control part.
586          }else {           *
587                      len = (int)((double)s->length * scaler * s->weight / rc->avg_weight);           * Unlike the theoritical scaled_curve_apply_advanced_parameters, here
588                      if (len < min_size[s->type-1]) {            /* force frame size */           * it's real encoding and we need to make sure we don't go so far from
589                              s->scaled_length = min_size[s->type-1];           * what is our ideal scaled curve.
590                              target -= s->scaled_length;           *-----------------------------------------------------------------------*/
591                              pass1_length -= s->length;  
592                      }else{          /* Compute the overflow we should compensate */
593                              s->scaled_length = 0;          if (s->type != XVID_TYPE_IVOP || rc->overflow > 0) {
594                      }                  double frametype_factor;
595          }                  double framesize_factor;
         }  
596    
597      scaler = (double)target / (double)pass1_length;                  /* Take only the desired part of overflow */
598      if (target <= 0 || pass1_length <= 0 || target >= pass1_length) {                  overflow = rc->overflow;
                 DPRINTF(XVID_DEBUG_RC,"undersize warning\n");  
                 scaler = 1.0;  
         }  
599    
600          DPRINTF(XVID_DEBUG_RC,                  /* Factor that will take care to decrease the overflow applied
601                          "After correction: target=%i, tot_length=%i, scaler=%f\n",                   * according to the importance of this frame type in term of
602                          (int)target, (int)pass1_length, scaler);                   * overall size */
603                    frametype_factor  = rc->count[XVID_TYPE_IVOP-1]*rc->avg_length[XVID_TYPE_IVOP-1];
604                    frametype_factor += rc->count[XVID_TYPE_PVOP-1]*rc->avg_length[XVID_TYPE_PVOP-1];
605                    frametype_factor += rc->count[XVID_TYPE_BVOP-1]*rc->avg_length[XVID_TYPE_BVOP-1];
606                    frametype_factor /= rc->count[s->type-1]*rc->avg_length[s->type-1];
607                    frametype_factor  = 1/frametype_factor;
608    
609                    /* Factor that will take care not to compensate too much for this frame
610                     * size */
611                    framesize_factor  = dbytes;
612                    framesize_factor /= rc->avg_length[s->type-1];
613    
614          for (i=0; i<rc->num_frames; i++) {                  /* Treat only the overflow part concerned by this frame type and size */
615                  stat_t * s = &rc->stats[i];                  overflow *= frametype_factor;
616    #if 0
617                    /* Leave this one alone, as it impacts badly on quality */
618                    overflow *= framesize_factor;
619    #endif
620    
621                  if (s->scaled_length==0) {      /* ignore frame with forced frame sizes */                  /* Apply the overflow strength imposed by the user */
622                          s->scaled_length = (int)((double)s->length * scaler * s->weight / rc->avg_weight);                  overflow *= (rc->param.overflow_control_strength/100.0f);
623                  }          } else {
624                    /* no negative overflow applied in IFrames because:
625                     *  - their role is important as they're references for P/BFrames.
626                     *  - there aren't much in typical sequences, so if an IFrame overflows too
627                     *    much, this overflow may impact the next IFrame too much and generate
628                     *    a sequence of poor quality frames */
629                    overflow = 0;
630          }          }
631    
632            /* Make sure we are not trying to compensate more overflow than we even have */
633            if (fabs(overflow) > fabs(rc->overflow))
634                    overflow = rc->overflow;
635    
636            /* Make sure the overflow doesn't make the frame size to get out of the range
637             * [-max_degradation..+max_improvment] */
638            if (overflow > dbytes*rc->param.max_overflow_improvement / 100) {
639                    if(overflow <= dbytes)
640                            dbytes += dbytes * rc->param.max_overflow_improvement / 100;
641                    else
642                            dbytes += overflow * rc->param.max_overflow_improvement / 100;
643            } else if (overflow < - dbytes * rc->param.max_overflow_degradation / 100) {
644                    dbytes -= dbytes * rc->param.max_overflow_degradation / 100;
645            } else {
646                    dbytes += overflow;
647  }  }
648    
649            /*-------------------------------------------------------------------------
650             * Frame bit allocation last part:
651             *
652             * Cap frame length so we don't reach neither bigger frame sizes than first
653             * pass nor smaller than the allowed minimum.
654             *-----------------------------------------------------------------------*/
655    
656    #ifdef PASS_SMALLER
657            if (dbytes > s->length) {
658                    dbytes = s->length;
659            }
660    #endif
661    
662            /* Prevent stupid desired sizes under logical values */
663            if (dbytes < rc->min_length[s->type-1]) {
664                    dbytes = rc->min_length[s->type-1];
665            }
666    
667            /*------------------------------------------------------------------------
668             * Desired frame length <-> quantizer mapping
669             *-----------------------------------------------------------------------*/
670    
671  static void  #ifdef BQUANT_PRESCALE
672  pre_process1(rc_2pass2_t * rc)          /* For bframes we prescale the quantizer to avoid too high quant scaling */
673  {          if(s->type == XVID_TYPE_BVOP) {
     int i;  
     double total1, total2;  
     uint64_t ivop_boost_total;  
674    
675      ivop_boost_total = 0;                  twopass_stat_t *b_ref = s;
     rc->curve_comp_error = 0;  
676    
677      for (i=0; i<3; i++) {                  /* Find the reference frame */
678          rc->tot_scaled_length[i] = 0;                  while(b_ref != &rc->stats[0] && b_ref->type == XVID_TYPE_BVOP)
679                            b_ref--;
680    
681                    /* Compute the original quant */
682                    s->quant  = 2*(100*s->quant - data->bquant_offset);
683                    s->quant += data->bquant_ratio - 1; /* to avoid rounding issues */
684                    s->quant  = s->quant/data->bquant_ratio - b_ref->quant;
685      }      }
686    #endif
687    
688      for (i=0; i<rc->num_frames; i++) {          /* Don't laugh at this very 'simple' quant<->size relationship, it
689          stat_t * s = &rc->stats[i];           * proves to be acurate enough for our algorithm */
690            scaled_quant = (double)s->quant*(double)s->length/(double)dbytes;
691    
692    #ifdef COMPENSATE_FORMULA
693            /* We know xvidcore will apply the bframe formula again, so we compensate
694             * it right now to make sure we would not apply it twice */
695            if(s->type == XVID_TYPE_BVOP) {
696    
697          rc->tot_scaled_length[s->type-1] += s->scaled_length;                  twopass_stat_t *b_ref = s;
698    
699          if (s->type == XVID_TYPE_IVOP) {                  /* Find the reference frame */
700              ivop_boost_total += s->scaled_length * rc->param.keyframe_boost / 100;                  while(b_ref != &rc->stats[0] && b_ref->type == XVID_TYPE_BVOP)
701          }                          b_ref--;
702    
703                    /* Compute the quant it would be if the core did not apply the bframe
704                     * formula */
705                    scaled_quant  = 100*scaled_quant - data->bquant_offset;
706                    scaled_quant += data->bquant_ratio - 1; /* to avoid rouding issues */
707                    scaled_quant /= data->bquant_ratio;
708      }      }
709    #endif
710    
711      rc->movie_curve = ((double)(rc->tot_scaled_length[XVID_TYPE_PVOP-1] + rc->tot_scaled_length[XVID_TYPE_BVOP-1] + ivop_boost_total) /          /* Quantizer has been scaled using floating point operations/results, we
712                                          (rc->tot_scaled_length[XVID_TYPE_PVOP-1] + rc->tot_scaled_length[XVID_TYPE_BVOP-1]));           * must cast it to integer */
713            data->quant = (int)scaled_quant;
714    
715      for(i=0; i<3; i++) {          /* Let's clip the computed quantizer, if needed */
716          if (rc->count[i] == 0 || rc->movie_curve == 0) {          if (data->quant < 1) {
717              rc->avg_length[i] = 1;                  data->quant = 1;
718            } else if (data->quant > 31) {
719                    data->quant = 31;
720          }else{          }else{
             rc->avg_length[i] = rc->tot_scaled_length[i] / rc->count[i] / rc->movie_curve;  
         }  
     }  
   
     /* alt curve stuff here */  
721    
722      if (rc->param.use_alt_curve) {                  /* The frame quantizer has not been clipped, this appears to be a good
723          const double avg_pvop = rc->avg_length[XVID_TYPE_PVOP-1];                   * computed quantizer, do not loose quantizer decimal part that we
724          const uint64_t tot_pvop = rc->tot_length[XVID_TYPE_PVOP-1];                   * accumulate for later reuse when its sum represents a complete
725          const uint64_t tot_bvop = rc->tot_length[XVID_TYPE_BVOP-1];                   * unit. */
726          const uint64_t tot_scaled_pvop = rc->tot_scaled_length[XVID_TYPE_PVOP-1];                  rc->quant_error[s->type-1][data->quant] += scaled_quant - (double)data->quant;
         const uint64_t tot_scaled_bvop = rc->tot_scaled_length[XVID_TYPE_BVOP-1];  
727    
728                  rc->alt_curve_low = avg_pvop - avg_pvop * (double)rc->param.alt_curve_low_dist / 100.0;                  if (rc->quant_error[s->type-1][data->quant] >= 1.0) {
729                  rc->alt_curve_low_diff = avg_pvop - rc->alt_curve_low;                          rc->quant_error[s->type-1][data->quant] -= 1.0;
730                  rc->alt_curve_high = avg_pvop + avg_pvop * (double)rc->param.alt_curve_high_dist / 100.0;                          data->quant++;
731                  rc->alt_curve_high_diff = rc->alt_curve_high - avg_pvop;                  } else if (rc->quant_error[s->type-1][data->quant] <= -1.0) {
732                            rc->quant_error[s->type-1][data->quant] += 1.0;
733          if (rc->param.alt_curve_use_auto) {                          data->quant--;
             if (tot_bvop + tot_pvop > tot_scaled_bvop + tot_scaled_pvop) {  
                                 rc->param.alt_curve_min_rel_qual = (int)(100.0 - (100.0 - 100.0 /  
                                         ((double)(tot_pvop + tot_bvop) / (double)(tot_scaled_pvop + tot_scaled_bvop))) * (double)rc->param.alt_curve_auto_str / 100.0);  
   
                                 if (rc->param.alt_curve_min_rel_qual < 20)  
                                         rc->param.alt_curve_min_rel_qual = 20;  
             }else{  
                                 rc->param.alt_curve_min_rel_qual = 100;  
734              }              }
735          }          }
                 rc->alt_curve_mid_qual = (1.0 + (double)rc->param.alt_curve_min_rel_qual / 100.0) / 2.0;  
                 rc->alt_curve_qual_dev = 1.0 - rc->alt_curve_mid_qual;  
736    
737          if (rc->param.alt_curve_low_dist > 100) {          /* Now we have a computed quant that is in the right quante range, with a
738                          switch(rc->param.alt_curve_type) {           * possible +1 correction due to cumulated error. We can now safely clip
739              case XVID_CURVE_SINE: // Sine Curve (high aggressiveness)           * the quantizer again with user's quant ranges. "Safely" means the Rate
740                                  rc->alt_curve_qual_dev *= 2.0 / (1.0 + sin(DEG2RAD * (avg_pvop * 90.0 / rc->alt_curve_low_diff)));           * Control could learn more about this quantizer, this knowledge is useful
741                                  rc->alt_curve_mid_qual = 1.0 - rc->alt_curve_qual_dev * sin(DEG2RAD * (avg_pvop * 90.0 / rc->alt_curve_low_diff));           * for future frames even if it this quantizer won't be really used atm,
742                                  break;           * that's why we don't perform this clipping earlier. */
743                          case XVID_CURVE_LINEAR: // Linear (medium aggressiveness)          if (data->quant < data->min_quant[s->type-1]) {
744                                  rc->alt_curve_qual_dev *= 2.0 / (1.0 + avg_pvop / rc->alt_curve_low_diff);                  data->quant = data->min_quant[s->type-1];
745                                  rc->alt_curve_mid_qual = 1.0 - rc->alt_curve_qual_dev * avg_pvop / rc->alt_curve_low_diff;          } else if (data->quant > data->max_quant[s->type-1]) {
746                                  break;                  data->quant = data->max_quant[s->type-1];
                         case XVID_CURVE_COSINE: // Cosine Curve (low aggressiveness)  
                                 rc->alt_curve_qual_dev *= 2.0 / (1.0 + (1.0 - cos(DEG2RAD * (avg_pvop * 90.0 / rc->alt_curve_low_diff))));  
                                 rc->alt_curve_mid_qual = 1.0 - rc->alt_curve_qual_dev * (1.0 - cos(DEG2RAD * (avg_pvop * 90.0 / rc->alt_curve_low_diff)));  
                         }  
                 }  
747      }      }
     /* --- */  
748    
749            if (data->quant < rc->min_quant) data->quant = rc->min_quant;
750    
751      total1=total2=0;          /* To avoid big quality jumps from frame to frame, we apply a "security"
752      for (i=0; i<rc->num_frames; i++) {           * rule that makes |last_quant - new_quant| <= 2. This rule only applies
753          stat_t * s = &rc->stats[i];           * to predicted frames (P and B) */
754            if (s->type != XVID_TYPE_IVOP && rc->last_quant[s->type-1] && capped_to_max_framesize == 0) {
         if (s->type != XVID_TYPE_IVOP) {  
             double dbytes,dbytes2;  
   
             dbytes = s->scaled_length / rc->movie_curve;  
             dbytes2 = 0; /* XXX: warning */  
             total1 += dbytes;  
             if (s->type == XVID_TYPE_BVOP)  
                 dbytes *= rc->avg_length[XVID_TYPE_PVOP-1] / rc->avg_length[XVID_TYPE_BVOP-1];  
   
             if (rc->param.use_alt_curve) {  
                 if (dbytes > rc->avg_length[XVID_TYPE_PVOP-1]) {  
755    
756                      if (dbytes >= rc->alt_curve_high) {                  if (data->quant > rc->last_quant[s->type-1] + 2) {
757                                                  dbytes2 = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev);                          data->quant = rc->last_quant[s->type-1] + 2;
758                      }else{                          DPRINTF(XVID_DEBUG_RC,
759                                                  switch(rc->param.alt_curve_type) {                                          "[xvid rc] -- frame %d p/b-frame quantizer prevented from rising too steeply\n",
760                          case XVID_CURVE_SINE :                                          data->frame_num);
                                                     dbytes2 = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * sin(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_high_diff)));  
                                                         break;  
                         case XVID_CURVE_LINEAR :  
                                                     dbytes2 = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) / rc->alt_curve_high_diff);  
                                                         break;  
                                                 case XVID_CURVE_COSINE :  
                                                     dbytes2 = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (1.0 - cos(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_high_diff))));  
                                                 }  
761                                          }                                          }
762                  }else{                  if (data->quant < rc->last_quant[s->type-1] - 2) {
763                      if (dbytes <= rc->alt_curve_low) {                          data->quant = rc->last_quant[s->type-1] - 2;
764                                                  dbytes2 = dbytes;                          DPRINTF(XVID_DEBUG_RC,
765                      }else{                                          "[xvid rc] -- frame:%d p/b-frame quantizer prevented from falling too steeply\n",
766                                                  switch(rc->param.alt_curve_type) {                                          data->frame_num);
                                                 case XVID_CURVE_SINE :  
                                                     dbytes2 = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * sin(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_low_diff)));  
                                                         break;  
                                                 case XVID_CURVE_LINEAR :  
                                                     dbytes2 = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) / rc->alt_curve_low_diff);  
                                                         break;  
                                                 case XVID_CURVE_COSINE :  
                                                     dbytes2 = dbytes * (rc->alt_curve_mid_qual + rc->alt_curve_qual_dev * (1.0 - cos(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_low_diff))));  
767                                                  }                                                  }
768                                          }                                          }
769    
770                  }          /* We don't want to pollute the RC histerisis when our computed quant has
771             * been computed from a capped frame size */
772            if (capped_to_max_framesize == 0)
773                    rc->last_quant[s->type-1] = data->quant;
774    
775            /* Don't forget to force 1st pass frame type ;-) */
776            data->type = s->type;
777    
778              }else{          return 0;
                 if (dbytes > rc->avg_length[XVID_TYPE_PVOP-1]) {  
                     dbytes2=((double)dbytes + (rc->avg_length[XVID_TYPE_PVOP-1] - dbytes) * rc->param.curve_compression_high / 100.0);  
                 }else{  
                                 dbytes2 = ((double)dbytes + (rc->avg_length[XVID_TYPE_PVOP-1] - dbytes) * rc->param.curve_compression_low / 100.0);  
779                  }                  }
780    
781    /*----------------------------------------------------------------------------
782     *--------------------------------------------------------------------------*/
783    
784    static int
785    rc_2pass2_after(rc_2pass2_t * rc, xvid_plg_data_t * data)
786    {
787            const char frame_type[4] = { 'i', 'p', 'b', 's'};
788            twopass_stat_t * s = &rc->stats[data->frame_num];
789    
790            /* Insufficent stats data */
791            if (data->frame_num >= rc->num_frames)
792                    return 0;
793    
794            /* Update the quantizer counter */
795            rc->quant_count[s->type-1][data->quant]++;
796    
797            /* Update the frame type overflow */
798            if (data->type == XVID_TYPE_IVOP) {
799                    int kfdiff = 0;
800    
801                    if(rc->KF_idx != rc->num_frames -1) {
802                            kfdiff  = rc->keyframe_locations[rc->KF_idx+1];
803                            kfdiff -= rc->keyframe_locations[rc->KF_idx];
804              }              }
805    
806              if (s->type == XVID_TYPE_BVOP) {                  /* Flush Keyframe overflow accumulator */
807                              dbytes2 *= rc->avg_length[XVID_TYPE_BVOP-1] / rc->avg_length[XVID_TYPE_PVOP-1];                  rc->overflow += rc->KFoverflow;
808                              if (dbytes2 < rc->min_length[XVID_TYPE_BVOP-1])  
809                                      dbytes2 = rc->min_length[XVID_TYPE_BVOP-1];                  /* Store the frame overflow to the keyframe accumulator */
810                    rc->KFoverflow = s->desired_length - data->length;
811    
812                    if (kfdiff > 1) {
813                            /* Non-consecutive keyframes case:
814                             * We can then divide this total keyframe overflow into equal parts
815                             * that we will distribute into regular overflow at each frame
816                             * between the sequence bounded by two IFrames */
817                            rc->KFoverflow_partial = rc->KFoverflow / (kfdiff - 1);
818              }else{              }else{
819                              if (dbytes2 < rc->min_length[XVID_TYPE_PVOP-1])                          /* Consecutive keyframes case:
820                                      dbytes2 = rc->min_length[XVID_TYPE_PVOP-1];                           * Flush immediatly the keyframe overflow and reset keyframe
821              }                           * overflow */
822              total2 += dbytes2;                          rc->overflow += rc->KFoverflow;
823                            rc->KFoverflow = 0;
824                            rc->KFoverflow_partial = 0;
825          }          }
826                    rc->KF_idx++;
827            } else {
828                    /* Accumulate the frame overflow */
829                    rc->overflow += s->desired_length - data->length;
830    
831                    /* Distribute part of the keyframe overflow */
832                    rc->overflow += rc->KFoverflow_partial;
833    
834                    /* Don't forget to substract that same amount from the total keyframe
835                     * overflow */
836                    rc->KFoverflow -= rc->KFoverflow_partial;
837      }      }
838    
839      rc->curve_comp_scale = total1 / total2;          rc->overflow += (s->error = s->desired_length - data->length);
840            rc->real_total += data->length;
841    
842      if (!rc->param.use_alt_curve) {          DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- frame:%d type:%c quant:%d stats:%d scaled:%d desired:%d actual:%d error:%d overflow:%.2f\n",
843          DPRINTF(XVID_DEBUG_RC, "middle frame size for asymmetric curve compression: %i\n",                          data->frame_num,
844              (int)(rc->avg_length[XVID_TYPE_PVOP-1] * rc->curve_comp_scale));                          frame_type[data->type-1],
845                            data->quant,
846                            s->length,
847                            s->scaled_length,
848                            s->desired_length,
849                            s->desired_length - s->error,
850                            -s->error,
851                            rc->overflow);
852    
853            return(0);
854      }      }
855    
856      if (rc->param.use_alt_curve) {  /*****************************************************************************
857          int bonus_bias = rc->param.alt_curve_bonus_bias;   * Helper functions definition
858          int oldquant = 1;   ****************************************************************************/
859    
860              if (rc->param.alt_curve_use_auto_bonus_bias)  /* Default buffer size for reading lines */
861                      bonus_bias = rc->param.alt_curve_min_rel_qual;  #define BUF_SZ   1024
862    
863              rc->alt_curve_curve_bias_bonus = (total1 - total2) * (double)bonus_bias / 100.0 / (double)(rc->num_frames /* - credits_frames */ - rc->num_keyframes);  /* Helper functions for reading/parsing the stats file */
864              rc->curve_comp_scale = ((total1 - total2) * (1.0 - (double)bonus_bias / 100.0) + total2) / total2;  static char *skipspaces(char *string);
865    static int iscomment(char *string);
866    static char *readline(FILE *f);
867    
868    /* This function counts the number of frame entries in the stats file
869     * It also counts the number of I Frames */
870    static int
871    statsfile_count_frames(rc_2pass2_t * rc, char * filename)
872    {
873            FILE * f;
874            char *line;
875            int lines;
876    
877            rc->num_frames = 0;
878            rc->num_keyframes = 0;
879    
880          /* special info for alt curve:  bias bonus and quantizer thresholds */          if ((f = fopen(filename, "rb")) == NULL)
881                    return(-1);
882    
883                  DPRINTF(XVID_DEBUG_RC, "avg scaled framesize:%i\n", (int)rc->avg_length[XVID_TYPE_PVOP-1]);          lines = 0;
884                  DPRINTF(XVID_DEBUG_RC, "bias bonus:%i bytes\n", (int)rc->alt_curve_curve_bias_bonus);          while ((line = readline(f)) != NULL) {
885    
886                  for (i=1; i <= (int)(rc->alt_curve_high*2)+1; i++) {                  char *ptr;
887              double curve_temp, dbytes;                  char type;
888              int newquant;                  int fields;
889    
890              dbytes = i;                  lines++;
891                          if (dbytes > rc->avg_length[XVID_TYPE_PVOP-1]) {  
892                  if (dbytes >= rc->alt_curve_high) {                  /* We skip spaces */
893                                          curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev);                  ptr = skipspaces(line);
894                  }else{  
895                                          switch(rc->param.alt_curve_type)                  /* Skip coment lines or empty lines */
896                                          {                  if(iscomment(ptr) || *ptr == '\0') {
897                                          case XVID_CURVE_SINE :                          free(line);
898                                                  curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * sin(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_high_diff)));                          continue;
                                                 break;  
                                         case XVID_CURVE_LINEAR :  
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) / rc->alt_curve_high_diff);  
                                                 break;  
                                         case XVID_CURVE_COSINE :  
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (1.0 - cos(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_high_diff))));  
                                         }  
899                                  }                                  }
900                          }else{  
901                  if (dbytes <= rc->alt_curve_low) {                  /* Read the stat line from buffer */
902                                          curve_temp = dbytes;                  fields = sscanf(ptr, "%c", &type);
903                  }else{  
904                                          switch(rc->param.alt_curve_type)                  /* Valid stats files have at least 7 fields */
905                                          {                  if (fields == 1) {
906                                          case XVID_CURVE_SINE :                          switch(type) {
907                                                  curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * sin(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_low_diff)));                          case 'i':
908                                                  break;                          case 'I':
909                                          case XVID_CURVE_LINEAR :                                  rc->num_keyframes++;
910                                                  curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) / rc->alt_curve_low_diff);                          case 'p':
911                            case 'P':
912                            case 'b':
913                            case 'B':
914                            case 's':
915                            case 'S':
916                                    rc->num_frames++;
917                                                  break;                                                  break;
918                                          case XVID_CURVE_COSINE :                          default:
919                                                  curve_temp = dbytes * (rc->alt_curve_mid_qual + rc->alt_curve_qual_dev * (1.0 - cos(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_low_diff))));                                  DPRINTF(XVID_DEBUG_RC,
920                                                    "[xvid rc] -- WARNING: L%d unknown frame type used (%c).\n",
921                                                    lines, type);
922                                          }                                          }
923                    } else {
924                                    DPRINTF(XVID_DEBUG_RC,
925                                                    "[xvid rc] -- WARNING: L%d misses some stat fields (%d).\n",
926                                                    lines, 7-fields);
927                                  }                                  }
928    
929                    /* Free the line buffer */
930                    free(line);
931                          }                          }
932    
933                          if (rc->movie_curve > 1.0)          /* We are done with the file */
934                                  dbytes *= rc->movie_curve;          fclose(f);
935    
936                          newquant = (int)(dbytes * 2.0 / (curve_temp * rc->curve_comp_scale + rc->alt_curve_curve_bias_bonus));          return(0);
                         if (newquant > 1) {  
                                 if (newquant != oldquant) {  
                     int percent = (int)((i - rc->avg_length[XVID_TYPE_PVOP-1]) * 100.0 / rc->avg_length[XVID_TYPE_PVOP-1]);  
                                         oldquant = newquant;  
                                         DPRINTF(XVID_DEBUG_RC, "quant:%i threshold at %i : %i percent\n", newquant, i, percent);  
                                 }  
                         }  
937                  }                  }
938    
939    /* open stats file(s) and read into rc->stats array */
940    static int
941    statsfile_load(rc_2pass2_t *rc, char * filename)
942    {
943            FILE * f;
944            int processed_entries;
945    
946            /* Opens the file */
947            if ((f = fopen(filename, "rb"))==NULL)
948                    return(-1);
949    
950            processed_entries = 0;
951            while(processed_entries < rc->num_frames) {
952                    char type;
953                    int fields;
954                    twopass_stat_t * s = &rc->stats[processed_entries];
955                    char *line, *ptr;
956    
957                    /* Read the line from the file */
958                    if((line = readline(f)) == NULL)
959                            break;
960    
961                    /* We skip spaces */
962                    ptr = skipspaces(line);
963    
964                    /* Skip comment lines or empty lines */
965                    if(iscomment(ptr) || *ptr == '\0') {
966                            free(line);
967                            continue;
968      }      }
969    
970      rc->overflow = 0;                  /* Reset this field that is optional */
971      rc->KFoverflow = 0;                  s->scaled_length = 0;
972      rc->KFoverflow_partial = 0;  
973      rc->KF_idx = 1;                  /* Convert the fields */
974                    fields = sscanf(ptr,
975                                                    "%c %d %d %d %d %d %d %d\n",
976                                                    &type,
977                                                    &s->quant,
978                                                    &s->blks[0], &s->blks[1], &s->blks[2],
979                                                    &s->length, &s->invariant /* not really yet */,
980                                                    &s->scaled_length);
981    
982                    /* Free line buffer, we don't need it anymore */
983                    free(line);
984    
985                    /* Fail silently, this has probably been warned in
986                     * statsfile_count_frames */
987                    if(fields != 7 && fields != 8)
988                            continue;
989    
990                    /* Convert frame type and compute the invariant length part */
991                    switch(type) {
992                    case 'i':
993                    case 'I':
994                            s->type = XVID_TYPE_IVOP;
995                            s->invariant /= INVARIANT_HEADER_PART_IVOP;
996                            break;
997                    case 'p':
998                    case 'P':
999                    case 's':
1000                    case 'S':
1001                            s->type = XVID_TYPE_PVOP;
1002                            s->invariant /= INVARIANT_HEADER_PART_PVOP;
1003                            break;
1004                    case 'b':
1005                    case 'B':
1006                            s->type = XVID_TYPE_BVOP;
1007                            s->invariant /= INVARIANT_HEADER_PART_BVOP;
1008                            break;
1009                    default:
1010                            /* Same as before, fail silently */
1011                            continue;
1012  }  }
1013    
1014                    /* Ok it seems it's been processed correctly */
1015                    processed_entries++;
1016            }
1017    
1018            /* Close the file */
1019            fclose(f);
1020    
1021            return(0);
1022    }
1023    
1024  static int rc_2pass2_create(xvid_plg_create_t * create, rc_2pass2_t ** handle)  /* pre-process the statistics data
1025     * - for each type, count, tot_length, min_length, max_length
1026     * - set keyframes_locations, tot_prescaled */
1027    static void
1028    first_pass_stats_prepare_data(rc_2pass2_t * rc)
1029  {  {
1030      xvid_plugin_2pass2_t * param = (xvid_plugin_2pass2_t *)create->param;          int i,j;
     rc_2pass2_t * rc;  
     int i;  
1031    
1032      rc = malloc(sizeof(rc_2pass2_t));          /* *rc fields initialization
1033      if (rc == NULL)           * NB: INT_MAX and INT_MIN are used in order to be immediately replaced
1034          return XVID_ERR_MEMORY;           *     with real values of the 1pass */
1035            for (i=0; i<3; i++) {
1036                    rc->count[i]=0;
1037                    rc->tot_length[i] = 0;
1038                    rc->tot_invariant[i] = 0;
1039                    rc->min_length[i] = INT_MAX;
1040            }
1041    
1042      rc->param = *param;          rc->max_length = INT_MIN;
1043            rc->tot_weighted = 0;
1044    
1045      if (rc->param.keyframe_boost <= 0) rc->param.keyframe_boost = 0;          /* Loop through all frames and find/compute all the stuff this function
1046      if (rc->param.payback_method <= 0) rc->param.payback_method = XVID_PAYBACK_PROP;           * is supposed to do */
1047      if (rc->param.bitrate_payback_delay <= 0) rc->param.bitrate_payback_delay = 250;          for (i=j=0; i<rc->num_frames; i++) {
1048      if (rc->param.curve_compression_high <= 0) rc->param.curve_compression_high = 0;                  twopass_stat_t * s = &rc->stats[i];
     if (rc->param.curve_compression_low <= 0) rc->param.curve_compression_low = 0;  
     if (rc->param.max_overflow_improvement <= 0) rc->param.max_overflow_improvement = 60;  
     if (rc->param.max_overflow_degradation <= 0) rc->param.max_overflow_degradation = 60;  
   
     if (rc->param.use_alt_curve <= 0) rc->param.use_alt_curve = 0;  
     if (rc->param.alt_curve_high_dist <= 0) rc->param.alt_curve_high_dist = 500;  
     if (rc->param.alt_curve_low_dist <= 0) rc->param.alt_curve_low_dist = 90;  
     if (rc->param.alt_curve_use_auto <= 0) rc->param.alt_curve_use_auto = 1;  
     if (rc->param.alt_curve_auto_str <= 0) rc->param.alt_curve_auto_str = 30;  
     if (rc->param.alt_curve_type <= 0) rc->param.alt_curve_type = XVID_CURVE_LINEAR;  
     if (rc->param.alt_curve_min_rel_qual <= 0) rc->param.alt_curve_min_rel_qual = 50;  
     if (rc->param.alt_curve_use_auto_bonus_bias <= 0) rc->param.alt_curve_use_auto_bonus_bias = 1;  
     if (rc->param.alt_curve_bonus_bias <= 0) rc->param.alt_curve_bonus_bias = 50;  
   
     if (rc->param.kftreshold <= 0) rc->param.kftreshold = 10;  
     if (rc->param.kfreduction <= 0) rc->param.kfreduction = 20;  
     if (rc->param.min_key_interval <= 0) rc->param.min_key_interval = 300;  
1049    
1050      if (!det_stats_length(rc, param->filename)){                  rc->count[s->type-1]++;
1051          DPRINTF(XVID_DEBUG_RC,"fopen %s failed\n", param->filename);                  rc->tot_length[s->type-1] += s->length;
1052          free(rc);                  rc->tot_invariant[s->type-1] += s->invariant;
1053          return XVID_ERR_FAIL;                  if (s->zone_mode != XVID_ZONE_QUANT)
1054                            rc->tot_weighted += (int)(s->weight*(s->length - s->invariant));
1055    
1056                    if (s->length < rc->min_length[s->type-1]) {
1057                            rc->min_length[s->type-1] = s->length;
1058      }      }
1059    
1060      if ((rc->stats = malloc(rc->num_frames * sizeof(stat_t))) == NULL) {                  if (s->length > rc->max_length) {
1061          free(rc);                          rc->max_length = s->length;
         return XVID_ERR_MEMORY;  
1062      }      }
1063    
1064      /*                  if (s->type == XVID_TYPE_IVOP) {
1065           * We need an extra location because we do as if the last frame were an                          rc->keyframe_locations[j] = i;
1066           * IFrame. This is needed because our code consider that frames between                          j++;
1067           * 2 IFrames form a natural sequence. So we store last frame as a                  }
          * keyframe location.  
          */  
     if ((rc->keyframe_locations = malloc((rc->num_keyframes + 1) * sizeof(int))) == NULL) {  
         free(rc->stats);  
         free(rc);  
         return XVID_ERR_MEMORY;  
1068      }      }
1069    
1070      if (!load_stats(rc, param->filename)) {          /* NB:
1071          DPRINTF(XVID_DEBUG_RC,"fopen %s failed\n", param->filename);           * The "per sequence" overflow system considers a natural sequence to be
1072          free(rc->keyframe_locations);           * formed by all frames between two iframes, so if we want to make sure
1073          free(rc->stats);           * the system does not go nuts during last sequence, we force the last
1074          free(rc);           * frame to appear in the keyframe locations array. */
1075          return XVID_ERR_FAIL;          rc->keyframe_locations[j] = i;
1076    
1077            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Min 1st pass IFrame length: %d\n", rc->min_length[0]);
1078            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Min 1st pass PFrame length: %d\n", rc->min_length[1]);
1079            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Min 1st pass BFrame length: %d\n", rc->min_length[2]);
1080      }      }
1081    
1082      /* pre-process our stats */  /* calculate zone weight "center" */
1083    static void
1084    zone_process(rc_2pass2_t *rc, const xvid_plg_create_t * create)
1085    {
1086            int i,j;
1087            int n = 0;
1088    
1089          if (rc->num_frames  < create->fbase/create->fincr) {          rc->tot_quant = 0;
1090                  rc->target = rc->param.bitrate / 8;     /* one second */          rc->tot_quant_invariant = 0;
1091          }else{  
1092                  rc->target =          if (create->num_zones == 0) {
1093                          ((uint64_t)rc->param.bitrate * (uint64_t)rc->num_frames * (uint64_t)create->fincr) / \                  for (j = 0; j < rc->num_frames; j++) {
1094                          ((uint64_t)create->fbase * 8);                          rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;
1095                            rc->stats[j].weight = 1.0;
1096                    }
1097                    n += rc->num_frames;
1098          }          }
1099    
     DPRINTF(XVID_DEBUG_RC, "Number of frames: %d\n", rc->num_frames);  
         DPRINTF(XVID_DEBUG_RC, "Frame rate: %d/%d\n", create->fbase, create->fincr);  
         DPRINTF(XVID_DEBUG_RC, "Target bitrate: %ld\n", rc->param.bitrate);  
         DPRINTF(XVID_DEBUG_RC, "Target filesize: %lld\n", rc->target);  
1100    
1101  #if 0          for(i=0; i < create->num_zones; i++) {
         rc->target -= rc->num_frames*24;        /* avi file header */  
 #endif  
1102    
1103                    int next = (i+1<create->num_zones) ? create->zones[i+1].frame : rc->num_frames;
1104    
1105          pre_process0(rc);                  /* Zero weight make no sense */
1106                    if (create->zones[i].increment == 0) create->zones[i].increment = 1;
1107                    /* And obviously an undetermined infinite makes even less sense */
1108                    if (create->zones[i].base == 0) create->zones[i].base = 1;
1109    
1110          if (rc->param.bitrate) {                  if (i==0 && create->zones[i].frame > 0) {
1111          zone_process(rc, create);                          for (j = 0; j < create->zones[i].frame && j < rc->num_frames; j++) {
1112                  internal_scale(rc);                                  rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;
1113      }else{                                  rc->stats[j].weight = 1.0;
         /* external scaler: ignore zone */  
         for (i=0;i<rc->num_frames;i++) {  
             rc->stats[i].zone_mode = XVID_ZONE_WEIGHT;  
             rc->stats[i].weight = 1.0;  
1114          }          }
1115          rc->avg_weight = 1.0;                          n += create->zones[i].frame;
         rc->tot_quant = 0;  
1116      }      }
         pre_process1(rc);  
1117    
1118      for (i=0; i<32;i++) {                  if (create->zones[i].mode == XVID_ZONE_WEIGHT) {
1119          rc->pquant_error[i] = 0;                          for (j = create->zones[i].frame; j < next && j < rc->num_frames; j++ ) {
1120          rc->bquant_error[i] = 0;                                  rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;
1121          rc->quant_count[i] = 0;                                  rc->stats[j].weight = (double)create->zones[i].increment / (double)create->zones[i].base;
1122                            }
1123                            next -= create->zones[i].frame;
1124                            n += next;
1125                    } else{  /* XVID_ZONE_QUANT */
1126                            for (j = create->zones[i].frame; j < next && j < rc->num_frames; j++ ) {
1127                                    rc->stats[j].zone_mode = XVID_ZONE_QUANT;
1128                                    rc->stats[j].weight = (double)create->zones[i].increment / (double)create->zones[i].base;
1129                                    rc->tot_quant += rc->stats[j].length;
1130                                    rc->tot_quant_invariant += rc->stats[j].invariant;
1131                            }
1132                    }
1133      }      }
   
     rc->fq_error = 0;  
   
     *handle = rc;  
         return(0);  
1134  }  }
1135    
1136    
1137  static int rc_2pass2_destroy(rc_2pass2_t * rc, xvid_plg_destroy_t * destroy)  /* scale the curve */
1138    static void
1139    first_pass_scale_curve_internal(rc_2pass2_t *rc)
1140  {  {
1141      free(rc->keyframe_locations);          int64_t target;
1142      free(rc->stats);          int64_t total_invariant;
1143          free(rc);          double scaler;
1144          return(0);          int i, num_MBs;
1145    
1146            /* We only scale texture data ! */
1147            total_invariant  = rc->tot_invariant[XVID_TYPE_IVOP-1];
1148            total_invariant += rc->tot_invariant[XVID_TYPE_PVOP-1];
1149            total_invariant += rc->tot_invariant[XVID_TYPE_BVOP-1];
1150            /* don't forget to substract header bytes used in quant zones, otherwise we
1151             * counting them twice */
1152            total_invariant -= rc->tot_quant_invariant;
1153    
1154            /* We remove the bytes used by the fixed quantizer zones during first pass
1155             * with the same quants, so we know very precisely how much that
1156             * represents */
1157            target  = rc->target;
1158            target -= rc->tot_quant;
1159    
1160            /* Let's compute a linear scaler in order to perform curve scaling */
1161            scaler = (double)(target - total_invariant) / (double)(rc->tot_weighted);
1162    
1163    #ifdef SMART_OVERFLOW_SETTING
1164            if (scaler > 0.9) {
1165                    rc->param.max_overflow_degradation *= 5;
1166                    rc->param.max_overflow_improvement *= 5;
1167                    rc->param.overflow_control_strength *= 3;
1168            } else if (scaler > 0.6) {
1169                    rc->param.max_overflow_degradation *= 2;
1170                    rc->param.max_overflow_improvement *= 2;
1171                    rc->param.overflow_control_strength *= 2;
1172            } else {
1173                    rc->min_quant = 2;
1174  }  }
1175    #endif
1176    
1177            /* Compute min frame lengths (for each frame type) according to the number
1178             * of MBs. We sum all block type counters of frame 0, this gives us the
1179             * number of MBs.
1180             *
1181             * We compare these hardcoded values with observed values in first pass
1182             * (determined in pre_process0).Then we keep the real minimum. */
1183    
1184            /* Number of MBs */
1185            num_MBs  = rc->stats[0].blks[0];
1186            num_MBs += rc->stats[0].blks[1];
1187            num_MBs += rc->stats[0].blks[2];
1188    
1189            /* Minimum for I frames */
1190            if(rc->min_length[XVID_TYPE_IVOP-1] > ((num_MBs*22) + 240) / 8)
1191                    rc->min_length[XVID_TYPE_IVOP-1] = ((num_MBs*22) + 240) / 8;
1192    
1193            /* Minimum for P/S frames */
1194            if(rc->min_length[XVID_TYPE_PVOP-1] > ((num_MBs) + 88)  / 8)
1195                    rc->min_length[XVID_TYPE_PVOP-1] = ((num_MBs) + 88)  / 8;
1196    
1197            /* Minimum for B frames */
1198            if(rc->min_length[XVID_TYPE_BVOP-1] > 8)
1199                    rc->min_length[XVID_TYPE_BVOP-1] = 8;
1200    
1201  static int rc_2pass2_before(rc_2pass2_t * rc, xvid_plg_data_t * data)          /* Perform an initial scale pass.
1202  {           *
1203      stat_t * s = &rc->stats[data->frame_num];           * If a frame size is scaled underneath our hardcoded minimums, then we
1204      int overflow;           * force the frame size to the minimum, and deduct the original & scaled
1205      int desired;           * frame length from the original and target total lengths */
1206      double dbytes;          for (i=0; i<rc->num_frames; i++) {
1207      double curve_temp;                  twopass_stat_t * s = &rc->stats[i];
1208      int capped_to_max_framesize = 0;                  int len;
1209    
1210          /*                  /* No need to scale frame length for which a specific quantizer is
1211           * This function is quite long but easy to understand. In order to simplify                   * specified thanks to zones */
1212           * the code path (a bit), we treat 3 cases that can return immediatly.                  if (s->zone_mode == XVID_ZONE_QUANT) {
1213           */                          s->scaled_length = s->length;
1214                            continue;
1215                    }
1216    
1217          /* First case: Another plugin has already set a quantizer */                  /* Compute the scaled length -- only non invariant data length is scaled */
1218      if (data->quant > 0)                  len = s->invariant + (int)((double)(s->length-s->invariant) * scaler * s->weight);
                 return(0);  
1219    
1220          /* Second case: We are in a Quant zone */                  /* Compare with the computed minimum */
1221          if (s->zone_mode == XVID_ZONE_QUANT) {                  if (len < rc->min_length[s->type-1]) {
1222                            /* This is a 'forced size' frame, set its frame size to the
1223                             * computed minimum */
1224                            s->scaled_length = rc->min_length[s->type-1];
1225    
1226                  rc->fq_error += s->weight;                          /* Remove both scaled and original size from their respective
1227                  data->quant = (int)rc->fq_error;                           * total counters, as we prepare a second pass for 'regular'
1228                  rc->fq_error -= data->quant;                           * frames */
1229                            target -= s->scaled_length;
1230                    } else {
1231                            /* Do nothing for now, we'll scale this later */
1232                            s->scaled_length = 0;
1233                    }
1234            }
1235    
1236                  s->desired_length = s->length;          /* The first pass on data substracted all 'forced size' frames from the
1237             * total counters. Now, it's possible to scale the 'regular' frames. */
1238    
1239                  return(0);          /* Scaling factor for 'regular' frames */
1240            scaler = (double)(target - total_invariant) / (double)(rc->tot_weighted);
1241    
1242            /* Do another pass with the new scaler */
1243            for (i=0; i<rc->num_frames; i++) {
1244                    twopass_stat_t * s = &rc->stats[i];
1245    
1246                    /* Ignore frame with forced frame sizes */
1247                    if (s->scaled_length == 0)
1248                            s->scaled_length = s->invariant + (int)((double)(s->length-s->invariant) * scaler * s->weight);
1249          }          }
1250    
1251          /* Third case: insufficent stats data */          /* Job done */
1252          if (data->frame_num >= rc->num_frames)          return;
1253                  return 0;  }
1254    
1255          /*  /* Apply all user settings to the scaled curve
1256           * The last case is the one every normal minded developer should fear to   * This implies:
1257           * maintain in a project :-)   *   keyframe boosting
1258           */   *   high/low compression */
1259    static void
1260    scaled_curve_apply_advanced_parameters(rc_2pass2_t * rc)
1261    {
1262            int i;
1263            int64_t ivop_boost_total;
1264    
1265          /* XXX: why by 8 */          /* Reset the rate controller (per frame type) total byte counters */
1266          overflow = rc->overflow / 8;          for (i=0; i<3; i++) rc->tot_scaled_length[i] = 0;
1267    
1268          /*          /* Compute total bytes for each frame type */
1269           * The rc->overflow field represents the overflow in current scene (between two          for (i=0; i<rc->num_frames;i++) {
1270           * IFrames) so we must not forget to reset it if we are enetring a new scene                  twopass_stat_t *s = &rc->stats[i];
1271           */                  rc->tot_scaled_length[s->type-1] += s->scaled_length;
         if (s->type == XVID_TYPE_IVOP) {  
                 overflow = 0;  
1272          }          }
1273    
1274          desired = s->scaled_length;          /* First we compute the total amount of bits needed, as being described by
1275             * the scaled distribution. During this pass over the complete stats data,
1276             * we see how much bits two user settings will get/give from/to p&b frames:
1277             *  - keyframe boosting
1278             *  - keyframe distance penalty */
1279            rc->KF_idx = 0;
1280            ivop_boost_total = 0;
1281            for (i=0; i<rc->num_frames; i++) {
1282                    twopass_stat_t * s = &rc->stats[i];
1283    
1284          dbytes = desired;                  /* Some more work is needed for I frames */
1285          if (s->type == XVID_TYPE_IVOP) {          if (s->type == XVID_TYPE_IVOP) {
1286                  dbytes += desired * rc->param.keyframe_boost / 100;                          int ivop_boost;
         }  
         dbytes /= rc->movie_curve;  
1287    
1288          /*                          /* Accumulate bytes needed for keyframe boosting */
1289           * We are now entering in the hard part of the algo, it was first designed                          ivop_boost = s->scaled_length*rc->param.keyframe_boost/100;
          * to work with i/pframes only streams, so the way it computes things is  
          * adapted to pframes only. However we can use it if we just take care to  
          * scale the bframes sizes to pframes sizes using the ratio avg_p/avg_p and  
          * then before really using values depending on frame sizes, scaling the  
          * value again with the inverse ratio  
          */  
         if (s->type == XVID_TYPE_BVOP) {  
                 dbytes *= rc->avg_length[XVID_TYPE_PVOP-1] / rc->avg_length[XVID_TYPE_BVOP-1];  
         }  
1290    
1291          /*  #if 0 /* ToDo: decide how to apply kfthresholding */
1292           * Apply user's choosen Payback method. Payback helps bitrate to follow the  #endif
1293           * scaled curve "paying back" past errors in curve previsions.                          /* If the frame size drops under the minimum length, then cap ivop_boost */
1294           */                          if (ivop_boost + s->scaled_length < rc->min_length[XVID_TYPE_IVOP-1])
1295          if (rc->param.payback_method == XVID_PAYBACK_BIAS) {                                  ivop_boost = rc->min_length[XVID_TYPE_IVOP-1] - s->scaled_length;
                 desired =(int)(rc->curve_comp_error / rc->param.bitrate_payback_delay);  
         }else{  
                 desired = (int)(rc->curve_comp_error * dbytes /  
                                                 rc->avg_length[XVID_TYPE_PVOP-1] / rc->param.bitrate_payback_delay);  
1296    
1297                  if (labs(desired) > fabs(rc->curve_comp_error)) {                          /* Accumulate the ivop boost */
1298                          desired = (int)rc->curve_comp_error;                          ivop_boost_total += ivop_boost;
1299    
1300                            /* Don't forget to update the keyframe index */
1301                            rc->KF_idx++;
1302                  }                  }
1303          }          }
1304    
1305          rc->curve_comp_error -= desired;          /* Initialize the IBoost tax ratio for P/S/B frames
1306             *
1307             * This ratio has to be applied to p/b/s frames in order to reserve
1308             * additional bits for keyframes (keyframe boosting) or if too much
1309             * keyframe distance is applied, bits retrieved from the keyframes.
1310             *
1311             * ie pb_length *= rc->pb_iboost_tax_ratio;
1312             *
1313             *    gives the ideal length of a p/b frame */
1314    
1315          /*          /* Compute the total length of p/b/s frames (temporary storage into
1316           * Alt curve treatment is not that hard to understand though the formulas           * movie_curve) */
1317           * seem to be huge. Alt treatment is basically a way to soft/harden the          rc->pb_iboost_tax_ratio  = (double)rc->tot_scaled_length[XVID_TYPE_PVOP-1];
1318           * curve flux applying sine/linear/cosine ratios          rc->pb_iboost_tax_ratio += (double)rc->tot_scaled_length[XVID_TYPE_BVOP-1];
1319           */  
1320            /* Compute the ratio described above
1321             *     taxed_total = sum(0, n, tax*scaled_length)
1322             * <=> taxed_total = tax.sum(0, n, scaled_length)
1323             * <=> tax = taxed_total / original_total */
1324            rc->pb_iboost_tax_ratio =
1325                    (rc->pb_iboost_tax_ratio - ivop_boost_total) /
1326                    rc->pb_iboost_tax_ratio;
1327    
1328          /* XXX: warning */          DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- IFrame boost tax ratio:%.2f\n",
1329          curve_temp = 0;                          rc->pb_iboost_tax_ratio);
1330    
1331          if (rc->param.use_alt_curve) {          /* Compute the average size of frames per frame type */
1332                  if (s->type != XVID_TYPE_IVOP)  {          for(i=0; i<3; i++) {
1333                          if (dbytes > rc->avg_length[XVID_TYPE_PVOP-1]) {                  /* Special case for missing type or weird case */
1334                                  if (dbytes >= rc->alt_curve_high) {                  if (rc->count[i] == 0 || rc->pb_iboost_tax_ratio == 0) {
1335                                          curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev);                          rc->avg_length[i] = 1;
                                 } else {  
                                         switch(rc->param.alt_curve_type) {  
                                         case XVID_CURVE_SINE :  
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * sin(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_high_diff)));  
                                                 break;  
                                         case XVID_CURVE_LINEAR :  
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) / rc->alt_curve_high_diff);  
                                                 break;  
                                         case XVID_CURVE_COSINE :  
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (1.0 - cos(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_high_diff))));  
                                         }  
                                 }  
1336                          } else {                          } else {
1337                                  if (dbytes <= rc->alt_curve_low){                          rc->avg_length[i] = rc->tot_scaled_length[i];
1338                                          curve_temp = dbytes;  
1339                            if (i == (XVID_TYPE_IVOP-1)) {
1340                                    /* I Frames total has to be added the boost total */
1341                                    rc->avg_length[i] += ivop_boost_total;
1342                                  } else {                                  } else {
1343                                          switch(rc->param.alt_curve_type) {                                  /* P/B frames has to taxed */
1344                                          case XVID_CURVE_SINE :                                  rc->avg_length[i] *= rc->pb_iboost_tax_ratio;
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * sin(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_low_diff)));  
                                                 break;  
                                         case XVID_CURVE_LINEAR :  
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual - rc->alt_curve_qual_dev * (dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) / rc->alt_curve_low_diff);  
                                                 break;  
                                         case XVID_CURVE_COSINE :  
                                                 curve_temp = dbytes * (rc->alt_curve_mid_qual + rc->alt_curve_qual_dev * (1.0 - cos(DEG2RAD * ((dbytes - rc->avg_length[XVID_TYPE_PVOP-1]) * 90.0 / rc->alt_curve_low_diff))));  
1345                                          }                                          }
1346    
1347                            /* Finally compute the average frame size */
1348                            rc->avg_length[i] /= (double)rc->count[i];
1349                                  }                                  }
1350                          }                          }
1351    
1352                          /*          /* Assymetric curve compression */
1353                           * End of code path for curve_temp, as told earlier, we are now          if (rc->param.curve_compression_high || rc->param.curve_compression_low) {
1354                           * obliged to scale the value to a bframe one using the inverse                  double symetric_total;
1355                           * ratio applied earlier                  double assymetric_delta_total;
                          */  
                         if (s->type == XVID_TYPE_BVOP)  
                                 curve_temp *= rc->avg_length[XVID_TYPE_BVOP-1] / rc->avg_length[XVID_TYPE_PVOP-1];  
1356    
1357                          curve_temp = curve_temp * rc->curve_comp_scale + rc->alt_curve_curve_bias_bonus;                  /* Like I frame boosting, assymetric curve compression modifies the total
1358                     * amount of needed bits, we must compute the ratio so we can prescale
1359                     lengths */
1360                    symetric_total = 0;
1361                    assymetric_delta_total = 0;
1362                    for (i=0; i<rc->num_frames; i++) {
1363                            double assymetric_delta;
1364                            double dbytes;
1365                            twopass_stat_t * s = &rc->stats[i];
1366    
1367                          desired += ((int)curve_temp);                          /* I Frames are not concerned by assymetric scaling */
1368                          rc->curve_comp_error += curve_temp - (int)curve_temp;                          if (s->type == XVID_TYPE_IVOP)
1369                  } else {                                  continue;
                         /*  
                          * End of code path for dbytes, as told earlier, we are now  
                          * obliged to scale the value to a bframe one using the inverse  
                          * ratio applied earlier  
                          */  
                         if (s->type == XVID_TYPE_BVOP)  
                                 dbytes *= rc->avg_length[XVID_TYPE_BVOP-1] / rc->avg_length[XVID_TYPE_PVOP-1];  
1370    
1371                          desired += ((int)dbytes);                          /* During the real run, we would have to apply the iboost tax */
1372                          rc->curve_comp_error += dbytes - (int)dbytes;                          dbytes = s->scaled_length * rc->pb_iboost_tax_ratio;
1373                  }  
1374                            /* Update the symmetric curve compression total */
1375                            symetric_total += dbytes;
1376    
1377                            /* Apply assymetric curve compression */
1378                            if (dbytes > rc->avg_length[s->type-1])
1379                                    assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * (double)rc->param.curve_compression_high / 100.0f;
1380                            else
1381                                    assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * (double)rc->param.curve_compression_low  / 100.0f;
1382    
1383                            /* Cap to the minimum frame size if needed */
1384                            if (dbytes + assymetric_delta < rc->min_length[s->type-1])
1385                                    assymetric_delta = rc->min_length[s->type-1] - dbytes;
1386    
1387          } else if ((rc->param.curve_compression_high + rc->param.curve_compression_low) &&      s->type != XVID_TYPE_IVOP) {                          /* Accumulate after assymetric curve compression */
1388                            assymetric_delta_total += assymetric_delta;
1389                    }
1390    
1391                  curve_temp = rc->curve_comp_scale;                  /* Compute the tax that all p/b frames have to pay in order to respect the
1392                  if (dbytes > rc->avg_length[XVID_TYPE_PVOP-1]) {                   * bit distribution changes that the assymetric compression curve imposes
1393                          curve_temp *= ((double)dbytes + (rc->avg_length[XVID_TYPE_PVOP-1] - dbytes) * rc->param.curve_compression_high / 100.0);                   * We want assymetric_total = sum(0, n-1, tax.scaled_length)
1394                     *      ie assymetric_total = ratio.sum(0, n-1, scaled_length)
1395                     *         ratio = assymetric_total / symmetric_total */
1396                    rc->assymetric_tax_ratio = ((double)symetric_total - (double)assymetric_delta_total) / (double)symetric_total;
1397                  } else {                  } else {
1398                          curve_temp *= ((double)dbytes + (rc->avg_length[XVID_TYPE_PVOP-1] - dbytes) * rc->param.curve_compression_low / 100.0);                  rc->assymetric_tax_ratio = 1.0f;
1399                  }                  }
1400    
1401                  /*          DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Assymetric tax ratio:%.2f\n", rc->assymetric_tax_ratio);
                  * End of code path for curve_temp, as told earlier, we are now  
                  * obliged to scale the value to a bframe one using the inverse  
                  * ratio applied earlier  
                  */  
                 if (s->type == XVID_TYPE_BVOP)  
                         curve_temp *= rc->avg_length[XVID_TYPE_BVOP-1] / rc->avg_length[XVID_TYPE_PVOP-1];  
1402    
1403                  desired += (int)curve_temp;          /* Last bits that need to be reset */
1404                  rc->curve_comp_error += curve_temp - (int)curve_temp;          rc->overflow = 0;
1405          } else {          rc->KFoverflow = 0;
1406                  /*          rc->KFoverflow_partial = 0;
1407                   * End of code path for dbytes, as told earlier, we are now          rc->KF_idx = 0;
1408                   * obliged to scale the value to a bframe one using the inverse          rc->desired_total = 0;
1409                   * ratio applied earlier          rc->real_total = 0;
1410    
1411            /* Job done */
1412            return;
1413    }
1414    
1415    /*****************************************************************************
1416     * VBV compliancy check and scale
1417     * MPEG-4 standard specifies certain restrictions for bitrate/framesize in VBR
1418     * to enable playback on devices with limited readspeed and memory (and which
1419     * aren't...)
1420     *
1421     * DivX profiles have 2 criteria: VBV as in MPEG standard
1422     *                                a limit on peak bitrate for any 3 seconds
1423     *
1424     * But if VBV is fulfilled, peakrate is automatically fulfilled in any profile
1425     * define so far, so we check for it (for completeness) but correct only VBV
1426     *
1427     *****************************************************************************/
1428    
1429    #define VBV_COMPLIANT 0
1430    #define VBV_UNDERFLOW 1 /* video buffer runs empty */
1431    #define VBV_OVERFLOW 2  /* doesn't exist for VBR encoding */
1432    #define VBV_PEAKRATE 4  /* peak bitrate (within 3s) violated */
1433    
1434    static int check_curve_for_vbv_compliancy(rc_2pass2_t * rc, const float fps)
1435    {
1436    /* We do all calculations in float, for higher accuracy,
1437       and in bytes for convenience
1438    
1439       typical values from DivX Home Theater profile:
1440       vbv_size= 384*1024 (384kB), vbv_initial= 288*1024 (75% fill)
1441       maxrate= 4000000 (4MBps), peakrate= 10000000 (10MBps)
1442    
1443       PAL: offset3s = 75 (3 seconds of 25fps)
1444       NTSC: offset3s = 90 (3 seconds of 29.97fps) or 72 (3 seconds of 23.976fps)
1445                   */                   */
1446                  if (s->type == XVID_TYPE_BVOP){  
1447                          dbytes *= rc->avg_length[XVID_TYPE_BVOP-1] / rc->avg_length[XVID_TYPE_PVOP-1];    const float vbv_size = (float)rc->param.vbv_size/8.f;
1448      float vbvfill = (float)rc->param.vbv_initial/8.f;
1449    
1450      const float maxrate = (float)rc->param.vbv_maxrate;
1451      const float peakrate = (float)rc->param.vbv_peakrate;
1452      const float r0 = (int)(maxrate/fps+0.5)/8.f;
1453    
1454      int bytes3s = 0;
1455      int offset3s = (int)(3.f*fps+0.5);
1456    
1457      int i;
1458      for (i=0; i<rc->num_frames; i++) {
1459    /* DivX 3s peak bitrate check  */
1460    
1461        bytes3s += rc->stats[i].scaled_length;
1462        if (i>=offset3s)
1463          bytes3s -= rc->stats[i-offset3s].scaled_length;
1464    
1465        if (8.f*bytes3s > 3*peakrate)
1466          return VBV_PEAKRATE;
1467    
1468    /* update vbv fill level */
1469    
1470        vbvfill += r0 - rc->stats[i].scaled_length;
1471    
1472    /* this check is _NOT_ an "overflow"! only reading from disk stops then */
1473        if (vbvfill > vbv_size)
1474          vbvfill = vbv_size;
1475    
1476    /* but THIS would be an underflow. report it! */
1477        if (vbvfill < 0)
1478          return VBV_UNDERFLOW;
1479                  }                  }
1480    
1481                  desired += (int)dbytes;    return VBV_COMPLIANT;
                 rc->curve_comp_error += dbytes - (int)dbytes;  
1482          }          }
1483    /* TODO: store min(vbvfill) and print "minimum buffer fill" */
1484    
1485    
1486    static int scale_curve_for_vbv_compliancy(rc_2pass2_t * rc, const float fps)
1487    {
1488    /* correct any VBV violations. Peak bitrate violations disappears
1489       by this automatically
1490    
1491       This implementation follows
1492    
1493       Westerink, Rajagopalan, Gonzales "Two-pass MPEG-2 variable-bitrate encoding"
1494       IBM J. RES. DEVELOP. VOL 43, No. 4, July 1999, p.471--488
1495    
1496       Thanks, guys! This paper rocks!!!
1497    */
1498    
1499          /*          /*
1500           * We can't do bigger frames than first pass, this would be stupid as first      For each scene of len N, we have to check up to N^2 possible buffer fills.
1501           * pass is quant=2 and that reaching quant=1 is not worth it. We would lose      This works well with MPEG-2 where N==12 or so, but for MPEG-4 it's a
1502           * many bytes and we would not not gain much quality.      little slow...
1503    
1504        TODO: Better control on VBVfill between scenes
1505           */           */
1506          if (desired > s->length) {  
1507                  rc->curve_comp_error += desired - s->length;    const float vbv_size = (float)rc->param.vbv_size/8.f;
1508                  desired = s->length;    const float vbv_initial = (float)rc->param.vbv_initial/8.f;
1509          }else{  
1510                  if (desired < rc->min_length[s->type-1]) {    const float maxrate = 0.9*rc->param.vbv_maxrate;
1511                          if (s->type == XVID_TYPE_IVOP){    const float vbv_low = 0.10f*vbv_size;
1512                                  rc->curve_comp_error -= rc->min_length[XVID_TYPE_IVOP-1] - desired;    const float r0 = (int)(maxrate/fps+0.5)/8.f;
1513    
1514      int i,k,l,n,violation = 0;
1515      float *scenefactor;
1516      int *scenestart;
1517      int *scenelength;
1518    
1519    /* first step: determine how many "scenes" there are and store their boundaries
1520       we could get all this from existing keyframe_positions, somehow, but there we
1521       don't have a min_scenelength, and it's no big deal to get it again.  */
1522    
1523      const int min_scenelength = (int)(fps+0.5);
1524      int num_scenes = 0;
1525      int last_scene = -999;
1526      for (i=0; i<rc->num_frames; i++) {
1527        if ( (rc->stats[i].type == XVID_TYPE_IVOP) && (i-last_scene>min_scenelength) )
1528        {
1529          last_scene = i;
1530          num_scenes++;
1531                          }                          }
                         desired = rc->min_length[s->type-1];  
1532                  }                  }
1533    
1534      scenefactor = (float*)malloc( num_scenes*sizeof(float) );
1535      scenestart = (int*)malloc( num_scenes*sizeof(int) );
1536      scenelength = (int*)malloc( num_scenes*sizeof(int) );
1537    
1538      if ((!scenefactor) || (!scenestart) || (!scenelength) )
1539      {
1540        free(scenefactor);
1541        free(scenestart);
1542        free(scenelength);
1543        /* remember: free(0) is valid and does exactly nothing. */
1544        return -1;
1545          }          }
1546    
1547          s->desired_length = desired;  /* count again and safe the length/position */
1548    
1549      num_scenes = 0;
1550      last_scene = -999;
1551      for (i=0; i<rc->num_frames; i++) {
1552        if ( (rc->stats[i].type == XVID_TYPE_IVOP) && (i-last_scene>min_scenelength) )
1553        {
1554          if (num_scenes>0)
1555            scenelength[num_scenes-1]=i-last_scene;
1556          scenestart[num_scenes]=i;
1557          num_scenes++;
1558          last_scene = i;
1559        }
1560      }
1561      scenelength[num_scenes-1]=i-last_scene;
1562    
1563          /* if this keyframe is too close to the next, reduce it's byte allotment  /* second step: check for each scene, how much we can scale its frames up or down
1564             XXX: why do we do this after setting the desired length  */     such that the VBV restriction is just fulfilled
1565    */
1566    
         if (s->type == XVID_TYPE_IVOP) {  
                 int KFdistance = rc->keyframe_locations[rc->KF_idx] - rc->keyframe_locations[rc->KF_idx - 1];  
1567    
1568                  if (KFdistance < rc->param.kftreshold) {  #define R(k,n) (((n)+1-(k))*r0)     /* how much enters the buffer between frame k and n */
1569      for (l=0; l<num_scenes;l++)
1570      {
1571        const int start = scenestart[l];
1572        const int length = scenelength[l];
1573        twopass_stat_t * frames = &rc->stats[start];
1574    
1575                          KFdistance = KFdistance - rc->param.min_key_interval;      float S0n,Skn;
1576        float f,minf = 99999.f;
1577    
1578                          if (KFdistance >= 0) {      S0n=0.;
1579                                  int KF_min_size;      for (n=0;n<=length-1;n++)
1580        {
1581          S0n += frames[n].scaled_length;
1582    
1583                                  KF_min_size = desired * (100 - rc->param.kfreduction) / 100;        k=0;
1584                                  if (KF_min_size < 1)        Skn = S0n;
1585                                          KF_min_size = 1;        f = (R(k,n-1) + (vbv_initial - vbv_low)) / Skn;
1586          if (f < minf)
1587            minf = f;
1588    
1589                                  desired = KF_min_size + (desired - KF_min_size) * KFdistance /        for (k=1;k<=n;k++)
1590                                          (rc->param.kftreshold - rc->param.min_key_interval);        {
1591            Skn -= frames[k].scaled_length;
1592    
1593                                  if (desired < 1)          f = (R(k,n-1) + (vbv_size - vbv_low)) / Skn;
1594                                          desired = 1;          if (f < minf)
1595                          }            minf = f;
1596                  }                  }
1597          }          }
1598    
1599          overflow = (int)((double)overflow * desired / rc->avg_length[XVID_TYPE_PVOP-1]);      /* special case: at the end, fill buffer up to vbv_initial again
1600           TODO: Allow other values for buffer fill between scenes
1601           e.g. if n=N is smallest f-value, then check for better value */
1602    
1603          /* Reign in overflow with huge frames */      n=length;
1604          if (labs(overflow) > labs(rc->overflow)) {      k=0;
1605                  overflow = rc->overflow;      Skn = S0n;
1606          }      f = R(k,n-1)/Skn;
1607        if (f < minf)
1608          minf = f;
1609    
1610          /* Make sure overflow doesn't run away */      for (k=1;k<=n-1;k++)
1611          if (overflow > desired * rc->param.max_overflow_improvement / 100) {      {
1612                  desired += (overflow <= desired) ? desired * rc->param.max_overflow_improvement / 100 :        Skn -= frames[k].scaled_length;
                         overflow * rc->param.max_overflow_improvement / 100;  
         } else if (overflow < desired * rc->param.max_overflow_degradation / -100){  
                 desired += desired * rc->param.max_overflow_degradation / -100;  
         } else {  
                 desired += overflow;  
         }  
1613    
1614          /* Make sure we are not higher than desired frame size */        f = (R(k,n-1) + (vbv_initial - vbv_low)) / Skn;
1615          if (desired > rc->max_length) {        if (f < minf)
1616                  capped_to_max_framesize = 1;          minf = f;
                 desired = rc->max_length;  
                 DPRINTF(XVID_DEBUG_RC,"[%i] Capped to maximum frame size\n",  
                                 data->frame_num);  
1617          }          }
1618    
1619          /* Make sure to not scale below the minimum framesize */  #ifdef VBV_DEBUG
1620          if (desired < rc->min_length[s->type-1]) {      printf("Scene %d (Frames %d-%d): VBVfactor %f\n", l, start, start+length-1 , minf);
1621                  desired = rc->min_length[s->type-1];  #endif
1622                  DPRINTF(XVID_DEBUG_RC,"[%i] Capped to minimum frame size\n",  
1623                                  data->frame_num);      scenefactor[l] = minf;
1624          }          }
1625    #undef R
1626    
1627          /*  /* last step: now we know of any scene how much it can be scaled up or down without
1628           * Don't laugh at this very 'simple' quant<->filesize relationship, it     violating VBV. Next, distribute bits from the evil scenes to the good ones */
          * proves to be acurate enough for our algorithm  
          */  
         data->quant= (s->quant * s->length) / desired;  
1629    
1630          /* Let's clip the computed quantizer, if needed */    do
1631          if (data->quant < 1) {    {
1632                  data->quant = 1;      float S_red = 0.f;    /* how much to redistribute */
1633          } else if (data->quant > 31) {      float S_elig = 0.f;   /* sum of bit for those scenes you can still swallow something*/
1634                  data->quant = 31;      int l;
         } else if (s->type != XVID_TYPE_IVOP) {  
1635    
1636                  /*      for (l=0;l<num_scenes;l++)   /* check how much is wrong */
1637                   * The frame quantizer has not been clipped, this appear to be a good      {
1638                   * computed quantizer, however past frames give us some info about how      const int start = scenestart[l];
1639                   * this quantizer performs against the algo prevision. Let's use this      const int length = scenelength[l];
1640                   * prevision to increase the quantizer when we observe a too big      twopass_stat_t * frames = &rc->stats[start];
                  * accumulated error  
                  */  
                 if (s->type== XVID_TYPE_BVOP) {  
                         rc->bquant_error[data->quant] += ((double)(s->quant * s->length) / desired) - data->quant;  
1641    
1642                          if (rc->bquant_error[data->quant] >= 1.0) {        if (scenefactor[l] == 1.) /* exactly 1 means "don't touch this anymore!" */
1643                                  rc->bquant_error[data->quant] -= 1.0;          continue;
                                 data->quant++;  
                         }  
                 } else {  
                         rc->pquant_error[data->quant] += ((double)(s->quant * s->length) / desired) - data->quant;  
1644    
1645                          if (rc->pquant_error[data->quant] >= 1.0) {        if (scenefactor[l] > 1.) /* within limits */
1646                                  rc->pquant_error[data->quant] -= 1.0;        {
1647                                  ++data->quant;          for (n= 0; n < length; n++)
1648              S_elig += frames[n].scaled_length;
1649                          }                          }
1650          else /* underflowing segment */
1651          {
1652            for (n= 0; n < length; n++)
1653            {
1654              float newbytes = (float)frames[n].scaled_length * scenefactor[l];
1655              S_red += (float)frames[n].scaled_length - (float)newbytes;
1656              frames[n].scaled_length =(int)newbytes;
1657                  }                  }
1658            scenefactor[l] = 1.f;
1659          }          }
   
         /*  
          * Now we have a computed quant that is in the right quante range, with a  
          * possible +1 correction due to cumulated error. We can now safely clip  
          * the quantizer again with user's quant ranges. "Safely" means the Rate  
          * Control could learn more about this quantizer, this knowledge is useful  
          * for future frames even if it this quantizer won't be really used atm,  
          * that's why we don't perform this clipping earlier.  
          */  
         if (data->quant < data->min_quant[s->type-1]) {  
                 data->quant = data->min_quant[s->type-1];  
         } else if (data->quant > data->max_quant[s->type-1]) {  
                 data->quant = data->max_quant[s->type-1];  
1660          }          }
1661    
1662          /*      if (S_red < 1.f)   /* no more underflows */
1663           * To avoid big quality jumps from frame to frame, we apply a "security"        break;
          * rule that makes |last_quant - new_quant| <= 2. This rule only applies  
          * to predicted frames (P and B)  
          */  
         if (s->type != XVID_TYPE_IVOP && rc->last_quant[s->type-1] && capped_to_max_framesize == 0) {  
1664    
1665                  if (data->quant > rc->last_quant[s->type-1] + 2) {      if (S_elig < 1.f)
1666                          data->quant = rc->last_quant[s->type-1] + 2;      {
1667                          DPRINTF(XVID_DEBUG_RC,  #ifdef VBV_DEBUG
1668                                          "[%i] p/b-frame quantizer prevented from rising too steeply\n",        fprintf(stderr,"Everything underflowing. \n");
1669                                          data->frame_num);  #endif
1670                  }        free(scenefactor);
1671                  if (data->quant < rc->last_quant[s->type-1] - 2) {        free(scenestart);
1672                          data->quant = rc->last_quant[s->type-1] - 2;        free(scenelength);
1673                          DPRINTF(XVID_DEBUG_RC,        return -2;
                                         "[%i] p/b-frame quantizer prevented from falling too steeply\n",  
                                         data->frame_num);  
1674                  }                  }
1675    
1676        const float f_red = (1.f + S_red/S_elig);
1677    
1678    #ifdef VBV_DEBUG
1679        printf("Moving %.0f kB to avoid buffer underflow, correction factor: %.5f\n",S_red/1024.f,f_red);
1680    #endif
1681    
1682        violation=0;
1683        for (l=0; l<num_scenes; l++)   /* scale remaining scenes up to meet total size */
1684        {
1685          const int start = scenestart[l];
1686          const int length = scenelength[l];
1687          twopass_stat_t * frames = &rc->stats[start];
1688    
1689          if (scenefactor[l] == 1.)
1690            continue;
1691    
1692          /* there shouldn't be any segments with factor<1 left, so all the rest is >1 */
1693    
1694          for (n= 0; n < length; n++)
1695          {
1696            frames[n].scaled_length = (int)(frames[n].scaled_length * f_red + 0.5);
1697          }          }
1698    
1699          /*        scenefactor[l] /= f_red;
1700           * We don't want to pollute the RC history results when our computed quant        if (scenefactor[l] < 1.f)
1701           * has been computed from a capped frame size          violation=1;
          */  
         if (capped_to_max_framesize == 0) {  
                 rc->last_quant[s->type-1] = data->quant;  
1702          }          }
1703    
1704      } while (violation);
1705    
1706      free(scenefactor);
1707      free(scenestart);
1708      free(scenelength);
1709          return 0;          return 0;
1710  }  }
1711    
1712    
1713    /*****************************************************************************
1714  static int rc_2pass2_after(rc_2pass2_t * rc, xvid_plg_data_t * data)   * Still more low level stuff (nothing to do with stats treatment)
1715     ****************************************************************************/
1716    
1717    /* This function returns an allocated string containing a complete line read
1718     * from the file starting at the current position */
1719    static char *
1720    readline(FILE *f)
1721  {  {
1722      stat_t * s = &rc->stats[data->frame_num];          char *buffer = NULL;
1723            int buffer_size = 0;
1724            int pos = 0;
1725    
1726          /* Insufficent stats data */          do {
1727      if (data->frame_num >= rc->num_frames)                  int c;
         return 0;  
   
     rc->quant_count[data->quant]++;  
1728    
1729      if (data->type == XVID_TYPE_IVOP) {                  /* Read a character from the stream */
1730          int kfdiff = (rc->keyframe_locations[rc->KF_idx] -      rc->keyframe_locations[rc->KF_idx - 1]);                  c = fgetc(f);
1731    
1732          rc->overflow += rc->KFoverflow;                  /* Is that EOF or new line ? */
1733          rc->KFoverflow = s->desired_length - data->length;                  if(c == EOF || c == '\n')
1734                            break;
1735    
1736          if (kfdiff > 1) {  // non-consecutive keyframes                  /* Do we have to update buffer ? */
1737              rc->KFoverflow_partial = rc->KFoverflow / (kfdiff - 1);                  if(pos >= buffer_size - 1) {
1738          }else{ // consecutive keyframes                          buffer_size += BUF_SZ;
1739                          rc->overflow += rc->KFoverflow;                          buffer = (char*)realloc(buffer, buffer_size);
1740                          rc->KFoverflow = 0;                          if (buffer == NULL)
1741                          rc->KFoverflow_partial = 0;                                  return(NULL);
         }  
         rc->KF_idx++;  
     }else{  
         // distribute part of the keyframe overflow  
         rc->overflow += s->desired_length - data->length + rc->KFoverflow_partial;  
         rc->KFoverflow -= rc->KFoverflow_partial;  
1742      }      }
1743    
1744      DPRINTF(XVID_DEBUG_RC, "[%i] quant:%i stats1:%i scaled:%i actual:%i overflow:%i\n",                  buffer[pos] = c;
1745          data->frame_num,                  pos++;
1746          data->quant,          } while(1);
         s->length,  
         s->scaled_length,  
         data->length,  
         rc->overflow);  
1747    
1748      return(0);          /* Read \n or EOF */
1749            if (buffer == NULL) {
1750                    /* EOF, so we reached the end of the file, return NULL */
1751                    if(feof(f))
1752                            return(NULL);
1753    
1754                    /* Just an empty line with just a newline, allocate a 1 byte buffer to
1755                     * store a zero length string */
1756                    buffer = (char*)malloc(1);
1757                    if(buffer == NULL)
1758                            return(NULL);
1759  }  }
1760    
1761            /* Zero terminated string */
1762            buffer[pos] = '\0';
1763    
1764            return(buffer);
1765    }
1766    
1767  int xvid_plugin_2pass2(void * handle, int opt, void * param1, void * param2)  /* This function returns a pointer to the first non space char in the given
1768     * string */
1769    static char *
1770    skipspaces(char *string)
1771  {  {
1772      switch(opt)          const char spaces[] =
1773      {      {
1774      case XVID_PLG_INFO :                          ' ','\t','\0'
1775          return 0;                  };
1776            const char *spacechar = spaces;
1777    
1778            if (string == NULL) return(NULL);
1779    
1780            while (*string != '\0') {
1781                    /* Test against space chars */
1782                    while (*spacechar != '\0') {
1783                            if (*string == *spacechar) {
1784                                    string++;
1785                                    spacechar = spaces;
1786                                    break;
1787                            }
1788                            spacechar++;
1789                    }
1790    
1791      case XVID_PLG_CREATE :                  /* No space char */
1792          return rc_2pass2_create((xvid_plg_create_t*)param1, param2);                  if (*spacechar == '\0') return(string);
1793            }
1794    
1795      case XVID_PLG_DESTROY :          return(string);
1796          return rc_2pass2_destroy((rc_2pass2_t*)handle, (xvid_plg_destroy_t*)param1);  }
1797    
1798      case XVID_PLG_BEFORE :  /* This function returns a boolean that tells if the string is only a
1799          return rc_2pass2_before((rc_2pass2_t*)handle, (xvid_plg_data_t*)param1);   * comment */
1800    static int
1801    iscomment(char *string)
1802    {
1803            const char comments[] =
1804                    {
1805                            '#',';', '%', '\0'
1806                    };
1807            const char *cmtchar = comments;
1808            int iscomment = 0;
1809    
1810            if (string == NULL) return(1);
1811    
1812            string = skipspaces(string);
1813    
1814            while(*cmtchar != '\0') {
1815                    if(*string == *cmtchar) {
1816                            iscomment = 1;
1817                            break;
1818                    }
1819                    cmtchar++;
1820            }
1821    
1822      case XVID_PLG_AFTER :          return(iscomment);
         return rc_2pass2_after((rc_2pass2_t*)handle, (xvid_plg_data_t*)param1);  
1823      }      }
1824    
1825      return XVID_ERR_FAIL;  #if 0
1826    static void
1827    stats_print(rc_2pass2_t * rc)
1828    {
1829            int i;
1830            const char frame_type[4] = { 'i', 'p', 'b', 's'};
1831    
1832            for (i=0; i<rc->num_frames; i++) {
1833                    twopass_stat_t *s = &rc->stats[i];
1834                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- frame:%d type:%c quant:%d stats:%d scaled:%d desired:%d actual:%d overflow(%c):%.2f\n",
1835                                    i, frame_type[s->type-1], -1, s->length, s->scaled_length,
1836                                    s->desired_length, -1, frame_type[s->type-1], -1.0f);
1837            }
1838  }  }
1839    #endif
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