[cvs] / xvidcore / src / plugins / plugin_2pass2.c Repository:
ViewVC logotype

Diff of /xvidcore/src/plugins/plugin_2pass2.c

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1.1, Tue Mar 25 10:58:33 2003 UTC revision 1.1.2.27, Wed Nov 19 15:59:41 2003 UTC
# Line 0  Line 1 
1    /******************************************************************************
2     *
3     *  XviD Bit Rate Controller Library
4     *  - VBR 2 pass bitrate controller implementation -
5     *
6     *  Copyright (C)      2002 Foxer <email?>
7     *                     2002 Dirk Knop <dknop@gwdg.de>
8     *                2002-2003 Edouard Gomez <ed.gomez@free.fr>
9     *                     2003 Pete Ross <pross@xvid.org>
10     *
11     *  This curve treatment algorithm is the one originally implemented by Foxer
12     *  and tuned by Dirk Knop for the XviD vfw frontend.
13     *
14     *  This program is free software; you can redistribute it and/or modify
15     *  it under the terms of the GNU General Public License as published by
16     *  the Free Software Foundation; either version 2 of the License, or
17     *  (at your option) any later version.
18     *
19     *  This program is distributed in the hope that it will be useful,
20     *  but WITHOUT ANY WARRANTY; without even the implied warranty of
21     *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22     *  GNU General Public License for more details.
23     *
24     *  You should have received a copy of the GNU General Public License
25     *  along with this program; if not, write to the Free Software
26     *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
27     *
28     * $Id$
29     *
30     *****************************************************************************/
31    
32    #undef COMPENSATE_FORMULA
33    
34    #include <stdio.h>
35    #include <math.h>
36    #include <limits.h>
37    
38    #include "../xvid.h"
39    #include "../image/image.h"
40    
41    /*****************************************************************************
42     * Some constants
43     ****************************************************************************/
44    
45    #define DEFAULT_KEYFRAME_BOOST 0
46    #define DEFAULT_OVERFLOW_CONTROL_STRENGTH 10
47    #define DEFAULT_CURVE_COMPRESSION_HIGH 0
48    #define DEFAULT_CURVE_COMPRESSION_LOW 0
49    #define DEFAULT_MAX_OVERFLOW_IMPROVEMENT 60
50    #define DEFAULT_MAX_OVERFLOW_DEGRADATION 60
51    
52    /* Keyframe settings */
53    #define DEFAULT_KFREDUCTION 20
54    #define DEFAULT_MIN_KEY_INTERVAL 1
55    
56    /*****************************************************************************
57     * Structures
58     ****************************************************************************/
59    
60    /* Statistics */
61    typedef struct {
62            int type;               /* first pass type */
63            int quant;              /* first pass quant */
64            int quant2;             /* Second pass quant */
65            int blks[3];                    /* k,m,y blks */
66            int length;             /* first pass length */
67            int scaled_length;      /* scaled length */
68            int desired_length;     /* desired length; calculated during encoding */
69            int error;
70    
71            int zone_mode;   /* XVID_ZONE_xxx */
72            double weight;
73    } twopass_stat_t;
74    
75    /* Context struct */
76    typedef struct
77    {
78            xvid_plugin_2pass2_t param;
79    
80            /*----------------------------------
81             * constant statistical data
82             *--------------------------------*/
83    
84            /* Number of frames of the sequence */
85            int num_frames;
86    
87            /* Number of Intra frames of the sequence */
88            int num_keyframes;
89    
90            /* Target filesize to reach */
91            uint64_t target;
92    
93            /* Count of each frame types */
94            int count[3];
95    
96            /* Total length of each frame types (1st pass) */
97            uint64_t tot_length[3];
98    
99            /* Average length of each frame types (used first for 1st pass data and
100             * then for scaled averages */
101            double avg_length[3];
102    
103            /* Minimum frame length allowed for each frame type */
104            int min_length[3];
105    
106            /* Total bytes per frame type once the curve has been scaled
107             * NB: advanced parameters do not change this value. This field
108             *     represents the total scaled w/o any advanced settings */
109            uint64_t tot_scaled_length[3];
110    
111            /* Maximum observed frame size observed during the first pass, the RC
112             * will try tp force all frame sizes in the second pass to be under that
113             * limit */
114            int max_length;
115    
116            /*----------------------------------
117             * Zones statistical data
118             *
119             * ToDo: Fix zones, current
120             *       implementation is buggy
121             *--------------------------------*/
122    
123            /* Average weight of the zones */
124            double avg_weight;
125    
126            /* Total length used by XVID_ZONE_QUANT zones */
127            int64_t tot_quant;
128    
129            /*----------------------------------
130             * Advanced settings helper ratios
131             *--------------------------------*/
132    
133            /* This the ratio that has to be applied to all p/b frames in order
134             * to reserve/retrieve bits for/from keyframe boosting and consecutive
135             * keyframe penalty */
136            double pb_iboost_tax_ratio;
137    
138            /* This the ratio to apply to all b/p frames in order to respect the
139             * assymetric curve compression while respecting a target filesize
140             * NB: The assymetric delta gain has to be computed before this ratio
141             *     is applied, and then the delta is added to the scaled size */
142            double assymetric_tax_ratio;
143    
144            /*----------------------------------
145             * Data from the stats file kept
146             * into RAM for easy access
147             *--------------------------------*/
148    
149            /* Array of keyframe locations
150             * eg: rc->keyframe_locations[100] returns the frame number of the 100th
151             *     keyframe */
152            int *keyframe_locations;
153    
154            /* Index of the last keyframe used in the keyframe_location */
155            int KF_idx;
156    
157            /* Array of all 1st pass data file -- see the twopass_stat_t structure
158             * definition for more details */
159            twopass_stat_t * stats;
160    
161            /*----------------------------------
162             * Histerysis helpers
163             *--------------------------------*/
164    
165            /* This field holds the int2float conversion errors of each quant per
166             * frame type, this allow the RC to keep track of rouding error and thus
167             * increase or decrease the chosen quant according to this residue */
168            double quant_error[3][32];
169    
170            /* This fields stores the count of each quant usage per frame type
171             * No real role but for debugging */
172            int quant_count[3][32];
173    
174            /* Last valid quantizer used per frame type, it allows quantizer
175             * increament/decreament limitation in order to avoid big image quality
176             * "jumps" */
177            int last_quant[3];
178    
179            /*----------------------------------
180             * Overflow control
181             *--------------------------------*/
182    
183            /* Current overflow that has to be distributed to p/b frames */
184            double overflow;
185    
186            /* Total overflow for keyframes -- not distributed directly */
187            double KFoverflow;
188    
189            /* Amount of keyframe overflow to introduce to the global p/b frame
190             * overflow counter at each encoded frame */
191            double KFoverflow_partial;
192    
193            /* Unknown ???
194             * ToDo: description */
195            double fq_error;
196    
197            /*----------------------------------
198             * Debug
199             *--------------------------------*/
200            double desired_total;
201            double real_total;
202    } rc_2pass2_t;
203    
204    
205    /*****************************************************************************
206     * Sub plugin functions prototypes
207     ****************************************************************************/
208    
209    static int rc_2pass2_create(xvid_plg_create_t * create, rc_2pass2_t ** handle);
210    static int rc_2pass2_before(rc_2pass2_t * rc, xvid_plg_data_t * data);
211    static int rc_2pass2_after(rc_2pass2_t * rc, xvid_plg_data_t * data);
212    static int rc_2pass2_destroy(rc_2pass2_t * rc, xvid_plg_destroy_t * destroy);
213    
214    /*****************************************************************************
215     * Plugin definition
216     ****************************************************************************/
217    
218    int
219    xvid_plugin_2pass2(void * handle, int opt, void * param1, void * param2)
220    {
221            switch(opt) {
222            case XVID_PLG_INFO :
223            case XVID_PLG_FRAME :
224                    return 0;
225    
226            case XVID_PLG_CREATE :
227                    return rc_2pass2_create((xvid_plg_create_t*)param1, param2);
228    
229            case XVID_PLG_DESTROY :
230                    return rc_2pass2_destroy((rc_2pass2_t*)handle, (xvid_plg_destroy_t*)param1);
231    
232            case XVID_PLG_BEFORE :
233                    return rc_2pass2_before((rc_2pass2_t*)handle, (xvid_plg_data_t*)param1);
234    
235            case XVID_PLG_AFTER :
236                    return rc_2pass2_after((rc_2pass2_t*)handle, (xvid_plg_data_t*)param1);
237            }
238    
239            return XVID_ERR_FAIL;
240    }
241    
242    /*****************************************************************************
243     * Sub plugin functions definitions
244     ****************************************************************************/
245    
246    /* First a few local helping function prototypes */
247    static  int statsfile_count_frames(rc_2pass2_t * rc, char * filename);
248    static  int statsfile_load(rc_2pass2_t *rc, char * filename);
249    static void zone_process(rc_2pass2_t *rc, const xvid_plg_create_t * create);
250    static void first_pass_stats_prepare_data(rc_2pass2_t * rc);
251    static void first_pass_scale_curve_internal(rc_2pass2_t *rc);
252    static void scaled_curve_apply_advanced_parameters(rc_2pass2_t * rc);
253    #if 0
254    static void stats_print(rc_2pass2_t * rc);
255    #endif
256    
257    /*----------------------------------------------------------------------------
258     *--------------------------------------------------------------------------*/
259    
260    static int
261    rc_2pass2_create(xvid_plg_create_t * create, rc_2pass2_t **handle)
262    {
263            xvid_plugin_2pass2_t * param = (xvid_plugin_2pass2_t *)create->param;
264            rc_2pass2_t * rc;
265            int i;
266    
267            rc = malloc(sizeof(rc_2pass2_t));
268            if (rc == NULL)
269                    return XVID_ERR_MEMORY;
270    
271            rc->param = *param;
272    
273            /* Initialize all defaults */
274    #define _INIT(a, b) if((a) <= 0) (a) = (b)
275            /* Let's set our defaults if needed */
276            _INIT(rc->param.keyframe_boost, DEFAULT_KEYFRAME_BOOST);
277            _INIT(rc->param.overflow_control_strength, DEFAULT_OVERFLOW_CONTROL_STRENGTH);
278            _INIT(rc->param.curve_compression_high, DEFAULT_CURVE_COMPRESSION_HIGH);
279            _INIT(rc->param.curve_compression_low, DEFAULT_CURVE_COMPRESSION_LOW);
280            _INIT(rc->param.max_overflow_improvement, DEFAULT_MAX_OVERFLOW_IMPROVEMENT);
281            _INIT(rc->param.max_overflow_degradation,  DEFAULT_MAX_OVERFLOW_DEGRADATION);
282    
283            /* Keyframe settings */
284            _INIT(rc->param.kfreduction, DEFAULT_KFREDUCTION);
285            _INIT(rc->param.min_key_interval, DEFAULT_MIN_KEY_INTERVAL);
286    #undef _INIT
287    
288            /* Initialize some stuff to zero */
289            for(i=0; i<3; i++) {
290                    int j;
291                    for (j=0; j<32; j++) {
292                            rc->quant_error[i][j] = 0;
293                            rc->quant_count[i][j] = 0;
294                    }
295            }
296    
297            for (i=0; i<3; i++) rc->last_quant[i] = 0;
298    
299            rc->fq_error = 0;
300    
301            /* Count frames (and intra frames) in the stats file, store the result into
302             * the rc structure */
303            if (statsfile_count_frames(rc, param->filename) == -1) {
304                    DPRINTF(XVID_DEBUG_RC,"[xvid rc] -- ERROR: fopen %s failed\n", param->filename);
305                    free(rc);
306                    return(XVID_ERR_FAIL);
307            }
308    
309            /* Allocate the stats' memory */
310            if ((rc->stats = malloc(rc->num_frames * sizeof(twopass_stat_t))) == NULL) {
311                    free(rc);
312                    return(XVID_ERR_MEMORY);
313            }
314    
315            /* Allocate keyframes location's memory
316             * PS: see comment in pre_process0 for the +1 location requirement */
317            rc->keyframe_locations = malloc((rc->num_keyframes + 1) * sizeof(int));
318            if (rc->keyframe_locations == NULL) {
319                    free(rc->stats);
320                    free(rc);
321                    return(XVID_ERR_MEMORY);
322            }
323    
324            /* Load the first pass stats */
325            if (statsfile_load(rc, param->filename) == -1) {
326                    DPRINTF(XVID_DEBUG_RC,"[xvid rc] -- ERROR: fopen %s failed\n", param->filename);
327                    free(rc->keyframe_locations);
328                    free(rc->stats);
329                    free(rc);
330                    return XVID_ERR_FAIL;
331            }
332    
333            /* Compute the target filesize */
334            if (rc->param.bitrate<0) {
335                    /* if negative, bitrate equals the target (in kbytes) */
336                    rc->target = (-rc->param.bitrate) * 1024;
337            } else if (rc->num_frames  < create->fbase/create->fincr) {
338                    /* Source sequence is less than 1s long, we do as if it was 1s long */
339                    rc->target = rc->param.bitrate / 8;
340            } else {
341                    /* Target filesize = bitrate/8 * numframes / framerate */
342                    rc->target =
343                            ((uint64_t)rc->param.bitrate * (uint64_t)rc->num_frames * \
344                             (uint64_t)create->fincr) / \
345                            ((uint64_t)create->fbase * 8);
346            }
347    
348            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Frame rate: %d/%d (%ffps)\n",
349                            create->fbase, create->fincr,
350                            (double)create->fbase/(double)create->fincr);
351            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Number of frames: %d\n", rc->num_frames);
352            if(rc->param.bitrate>=0)
353                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Target bitrate: %ld\n", rc->param.bitrate);
354            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Target filesize: %lld\n", rc->target);
355    
356            /* Compensate the average frame overhead caused by the container */
357            rc->target -= rc->num_frames*rc->param.container_frame_overhead;
358            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Container Frame overhead: %d\n", rc->param.container_frame_overhead);
359            if(rc->param.container_frame_overhead)
360                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- New target filesize after container compensation: %lld\n", rc->target);
361    
362            /* Gathers some information about first pass stats:
363             *  - finds the minimum frame length for each frame type during 1st pass.
364             *     rc->min_size[]
365             *  - determines the maximum frame length observed (no frame type distinction).
366             *     rc->max_size
367             *  - count how many times each frame type has been used.
368             *     rc->count[]
369             *  - total bytes used per frame type
370             *     rc->total[]
371             *  - store keyframe location
372             *     rc->keyframe_locations[]
373             */
374            first_pass_stats_prepare_data(rc);
375    
376            /* When bitrate is not given it means it has been scaled by an external
377             * application */
378            if (rc->param.bitrate) {
379                    /* Apply zone settings */
380                    zone_process(rc, create);
381                    /* Perform internal curve scaling */
382                    first_pass_scale_curve_internal(rc);
383            } else {
384                    /* External scaling -- zones are ignored */
385                    for (i=0;i<rc->num_frames;i++) {
386                            rc->stats[i].zone_mode = XVID_ZONE_WEIGHT;
387                            rc->stats[i].weight = 1.0;
388                    }
389                    rc->avg_weight = 1.0;
390                    rc->tot_quant = 0;
391            }
392    
393            /* Apply advanced curve options, and compute some parameters in order to
394             * shape the curve in the BEFORE/AFTER pair of functions */
395            scaled_curve_apply_advanced_parameters(rc);
396    
397            *handle = rc;
398            return(0);
399    }
400    
401    /*----------------------------------------------------------------------------
402     *--------------------------------------------------------------------------*/
403    
404    static int
405    rc_2pass2_destroy(rc_2pass2_t * rc, xvid_plg_destroy_t * destroy)
406    {
407            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- target_total:%lld desired_total:%.2f (%.2f%%) actual_total:%.2f (%.2f%%)\n",
408                            rc->target,
409                            rc->desired_total,
410                            100*rc->desired_total/(double)rc->target,
411                            rc->real_total,
412                            100*rc->real_total/(double)rc->target);
413    
414            free(rc->keyframe_locations);
415            free(rc->stats);
416            free(rc);
417            return(0);
418    }
419    
420    /*----------------------------------------------------------------------------
421     *--------------------------------------------------------------------------*/
422    
423    static int
424    rc_2pass2_before(rc_2pass2_t * rc, xvid_plg_data_t * data)
425    {
426            twopass_stat_t * s = &rc->stats[data->frame_num];
427            double dbytes;
428            double scaled_quant;
429            double overflow;
430            int capped_to_max_framesize = 0;
431    
432            /* This function is quite long but easy to understand. In order to simplify
433             * the code path (a bit), we treat 3 cases that can return immediatly. */
434    
435            /* First case: Another plugin has already set a quantizer */
436            if (data->quant > 0)
437                    return(0);
438    
439            /* Second case: We are in a Quant zone */
440            if (s->zone_mode == XVID_ZONE_QUANT) {
441                    rc->fq_error += s->weight;
442                    data->quant = (int)rc->fq_error;
443                    rc->fq_error -= data->quant;
444    
445                    s->desired_length = s->length;
446    
447                    return(0);
448            }
449    
450            /* Third case: insufficent stats data */
451            if (data->frame_num >= rc->num_frames)
452                    return(0);
453    
454            /*************************************************************************/
455            /*************************************************************************/
456            /*************************************************************************/
457    
458            /*-------------------------------------------------------------------------
459             * Frame bit allocation first part
460             *
461             * First steps apply user settings, just like it is done in the theoritical
462             * scaled_curve_apply_advanced_parameters
463             *-----------------------------------------------------------------------*/
464    
465            /* Set desired to what we are wanting to obtain for this frame */
466            dbytes = (double)s->scaled_length;
467    
468            /* IFrame user settings*/
469            if (s->type == XVID_TYPE_IVOP) {
470    
471                    /* Keyframe boosting -- All keyframes benefit from it */
472                    dbytes += dbytes*rc->param.keyframe_boost / 100;
473    
474                    /* Applies keyframe penalties, but not the first frame */
475                    if (rc->KF_idx) {
476                            int penalty_distance;
477    
478                            /* Minimum keyframe distance penalties */
479                            penalty_distance  = rc->param.min_key_interval;
480                            penalty_distance -= rc->keyframe_locations[rc->KF_idx];
481                            penalty_distance += rc->keyframe_locations[rc->KF_idx-1];
482    
483                            /* Ah ah ! guilty keyframe, you're under arrest ! */
484                            if (penalty_distance > 0)
485                                    dbytes -= dbytes*penalty_distance*rc->param.kfreduction/100;
486                    }
487            } else {
488    
489                    /* P/S/B frames must reserve some bits for iframe boosting */
490                    dbytes *= rc->pb_iboost_tax_ratio;
491    
492                    /* Apply assymetric curve compression */
493                    if (rc->param.curve_compression_high || rc->param.curve_compression_low) {
494                            double assymetric_delta;
495    
496                            /* Compute the assymetric delta, this is computed before applying
497                             * the tax, as done in the pre_process function */
498                            if (dbytes > rc->avg_length[s->type-1])
499                                    assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * rc->param.curve_compression_high / 100.0;
500                            else
501                                    assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * rc->param.curve_compression_low  / 100.0;
502    
503                            /* Now we must apply the assymetric tax, else our curve compression
504                             * would not give a theoritical target size equal to what it is
505                             * expected */
506                            dbytes *= rc->assymetric_tax_ratio;
507    
508                            /* Now we can add the assymetric delta */
509                            dbytes += assymetric_delta;
510                    }
511            }
512    
513            /* That is what we would like to have -- Don't put that chunk after
514             * overflow control, otherwise, overflow is counted twice and you obtain
515             * half sized bitrate sequences */
516            s->desired_length  = (int)dbytes;
517            rc->desired_total += dbytes;
518    
519            /*------------------------------------------------------------------------
520             * Frame bit allocation: overflow control part.
521             *
522             * Unlike the theoritical scaled_curve_apply_advanced_parameters, here
523             * it's real encoding and we need to make sure we don't go so far from
524             * what is our ideal scaled curve.
525             *-----------------------------------------------------------------------*/
526    
527            /* Compute the overflow we should compensate */
528            if (s->type != XVID_TYPE_IVOP) {
529                    double frametype_factor;
530                    double framesize_factor;
531    
532                    /* Take only the desired part of overflow */
533                    overflow = rc->overflow;
534    
535                    /* Factor that will take care to decrease the overflow applied
536                     * according to the importance of this frame type in term of
537                     * overall size */
538                    frametype_factor  = rc->count[XVID_TYPE_IVOP-1]*rc->avg_length[XVID_TYPE_IVOP-1];
539                    frametype_factor += rc->count[XVID_TYPE_PVOP-1]*rc->avg_length[XVID_TYPE_PVOP-1];
540                    frametype_factor += rc->count[XVID_TYPE_BVOP-1]*rc->avg_length[XVID_TYPE_BVOP-1];
541                    frametype_factor /= rc->count[s->type-1]*rc->avg_length[s->type-1];
542                    frametype_factor  = 1/frametype_factor;
543    
544                    /* Factor that will take care not to compensate too much for this frame
545                     * size */
546                    framesize_factor  = dbytes;
547                    framesize_factor /= rc->avg_length[s->type-1];
548    
549                    /* Treat only the overflow part concerned by this frame type and size */
550                    overflow *= frametype_factor;
551    #if 0
552                    /* Leave this one alone, as it impacts badly on quality */
553                    overflow *= framesize_factor;
554    #endif
555    
556                    /* Apply the overflow strength imposed by the user */
557                    overflow *= (rc->param.overflow_control_strength/100.0f);
558            } else {
559                    /* no overflow applied in IFrames because:
560                     *  - their role is important as they're references for P/BFrames.
561                     *  - there aren't much in typical sequences, so if an IFrame overflows too
562                     *    much, this overflow may impact the next IFrame too much and generate
563                     *    a sequence of poor quality frames */
564                    overflow = 0;
565            }
566    
567            /* Make sure we are not trying to compensate more overflow than we even have */
568            if (fabs(overflow) > fabs(rc->overflow))
569                    overflow = rc->overflow;
570    
571            /* Make sure the overflow doesn't make the frame size to get out of the range
572             * [-max_degradation..+max_improvment] */
573            if (overflow > dbytes*rc->param.max_overflow_improvement / 100) {
574                    if(overflow <= dbytes)
575                            dbytes += dbytes * rc->param.max_overflow_improvement / 100;
576                    else
577                            dbytes += overflow * rc->param.max_overflow_improvement / 100;
578            } else if (overflow < - dbytes * rc->param.max_overflow_degradation / 100) {
579                    dbytes -= dbytes * rc->param.max_overflow_degradation / 100;
580            } else {
581                    dbytes += overflow;
582            }
583    
584            /*-------------------------------------------------------------------------
585             * Frame bit allocation last part:
586             *
587             * Cap frame length so we don't reach neither bigger frame sizes than first
588             * pass nor smaller than the allowed minimum.
589             *-----------------------------------------------------------------------*/
590    
591            if (dbytes > s->length) {
592                    dbytes = s->length;
593            } else if (dbytes < rc->min_length[s->type-1]) {
594                    dbytes = rc->min_length[s->type-1];
595            } else if (dbytes > rc->max_length) {
596                    /* ToDo: this condition is always wrong as max_length == maximum frame
597                     * length of first pass, so the first condition already caps the frame
598                     * size... */
599                    capped_to_max_framesize = 1;
600                    dbytes = rc->max_length;
601                    DPRINTF(XVID_DEBUG_RC,"[xvid rc] -- frame:%d Capped to maximum frame size\n",
602                                    data->frame_num);
603            }
604    
605            /*------------------------------------------------------------------------
606             * Desired frame length <-> quantizer mapping
607             *-----------------------------------------------------------------------*/
608    
609            /* For bframes we must retrieve the original quant used (sent to xvidcore)
610             * as core applies the bquant formula before writing the stat log entry */
611            if(s->type == XVID_TYPE_BVOP) {
612    
613                    twopass_stat_t *b_ref = s;
614    
615                    /* Find the reference frame */
616                    while(b_ref != &rc->stats[0] && b_ref->type == XVID_TYPE_BVOP)
617                            b_ref--;
618    
619                    /* Compute the original quant */
620                    s->quant  = 2*(100*s->quant - data->bquant_offset);
621                    s->quant += data->bquant_ratio - 1; /* to avoid rouding issues */
622                    s->quant  = s->quant/data->bquant_ratio - b_ref->quant;
623            }
624    
625            /* Don't laugh at this very 'simple' quant<->filesize relationship, it
626             * proves to be acurate enough for our algorithm */
627            scaled_quant = (double)s->quant*(double)s->length/(double)dbytes;
628    
629    #ifdef COMPENSATE_FORMULA
630            /* We know xvidcore will apply the bframe formula again, so we compensate
631             * it right now to make sure we would not apply it twice */
632            if(s->type == XVID_TYPE_BVOP) {
633    
634                    twopass_stat_t *b_ref = s;
635    
636                    /* Find the reference frame */
637                    while(b_ref != &rc->stats[0] && b_ref->type == XVID_TYPE_BVOP)
638                            b_ref--;
639    
640                    /* Compute the quant it would be if the core did not apply the bframe
641                     * formula */
642                    scaled_quant  = 100*scaled_quant - data->bquant_offset;
643                    scaled_quant += data->bquant_ratio - 1; /* to avoid rouding issues */
644                    scaled_quant /= data->bquant_ratio;
645            }
646    #endif
647    
648            /* Quantizer has been scaled using floating point operations/results, we
649             * must cast it to integer */
650            data->quant = (int)scaled_quant;
651    
652            /* Let's clip the computed quantizer, if needed */
653            if (data->quant < 1) {
654                    data->quant = 1;
655            } else if (data->quant > 31) {
656                    data->quant = 31;
657            } else {
658    
659                    /* The frame quantizer has not been clipped, this appears to be a good
660                     * computed quantizer, do not loose quantizer decimal part that we
661                     * accumulate for later reuse when its sum represents a complete
662                     * unit. */
663                    rc->quant_error[s->type-1][data->quant] += scaled_quant - (double)data->quant;
664    
665                    if (rc->quant_error[s->type-1][data->quant] >= 1.0) {
666                            rc->quant_error[s->type-1][data->quant] -= 1.0;
667                            data->quant++;
668                    } else if (rc->quant_error[s->type-1][data->quant] <= -1.0) {
669                            rc->quant_error[s->type-1][data->quant] += 1.0;
670                            data->quant--;
671                    }
672            }
673    
674            /* Now we have a computed quant that is in the right quante range, with a
675             * possible +1 correction due to cumulated error. We can now safely clip
676             * the quantizer again with user's quant ranges. "Safely" means the Rate
677             * Control could learn more about this quantizer, this knowledge is useful
678             * for future frames even if it this quantizer won't be really used atm,
679             * that's why we don't perform this clipping earlier. */
680            if (data->quant < data->min_quant[s->type-1]) {
681                    data->quant = data->min_quant[s->type-1];
682            } else if (data->quant > data->max_quant[s->type-1]) {
683                    data->quant = data->max_quant[s->type-1];
684            }
685    
686            /* To avoid big quality jumps from frame to frame, we apply a "security"
687             * rule that makes |last_quant - new_quant| <= 2. This rule only applies
688             * to predicted frames (P and B) */
689            if (s->type != XVID_TYPE_IVOP && rc->last_quant[s->type-1] && capped_to_max_framesize == 0) {
690    
691                    if (data->quant > rc->last_quant[s->type-1] + 2) {
692                            data->quant = rc->last_quant[s->type-1] + 2;
693                            DPRINTF(XVID_DEBUG_RC,
694                                            "[xvid rc] -- frame %d p/b-frame quantizer prevented from rising too steeply\n",
695                                            data->frame_num);
696                    }
697                    if (data->quant < rc->last_quant[s->type-1] - 2) {
698                            data->quant = rc->last_quant[s->type-1] - 2;
699                            DPRINTF(XVID_DEBUG_RC,
700                                            "[xvid rc] -- frame:%d p/b-frame quantizer prevented from falling too steeply\n",
701                                            data->frame_num);
702                    }
703            }
704    
705            /* We don't want to pollute the RC histerisis when our computed quant has
706             * been computed from a capped frame size */
707            if (capped_to_max_framesize == 0)
708                    rc->last_quant[s->type-1] = data->quant;
709    
710            /* Don't forget to force 1st pass frame type ;-) */
711            data->type = s->type;
712    
713            /* Store the quantizer into the statistics -- Used to compensate the double
714             * formula symptom */
715            s->quant2 = data->quant;
716    
717            return 0;
718    }
719    
720    /*----------------------------------------------------------------------------
721     *--------------------------------------------------------------------------*/
722    
723    static int
724    rc_2pass2_after(rc_2pass2_t * rc, xvid_plg_data_t * data)
725    {
726            const char frame_type[4] = { 'i', 'p', 'b', 's'};
727            twopass_stat_t * s = &rc->stats[data->frame_num];
728    
729            /* Insufficent stats data */
730            if (data->frame_num >= rc->num_frames)
731                    return 0;
732    
733            /* Update the quantizer counter */
734            rc->quant_count[s->type-1][data->quant]++;
735    
736            /* Update the frame type overflow */
737            if (data->type == XVID_TYPE_IVOP) {
738                    int kfdiff = 0;
739    
740                    if(rc->KF_idx != rc->num_frames -1) {
741                            kfdiff  = rc->keyframe_locations[rc->KF_idx+1];
742                            kfdiff -= rc->keyframe_locations[rc->KF_idx];
743                    }
744    
745                    /* Flush Keyframe overflow accumulator */
746                    rc->overflow += rc->KFoverflow;
747    
748                    /* Store the frame overflow to the keyframe accumulator */
749                    rc->KFoverflow = s->desired_length - data->length;
750    
751                    if (kfdiff > 1) {
752                            /* Non-consecutive keyframes case:
753                             * We can then divide this total keyframe overflow into equal parts
754                             * that we will distribute into regular overflow at each frame
755                             * between the sequence bounded by two IFrames */
756                            rc->KFoverflow_partial = rc->KFoverflow / (kfdiff - 1);
757                    } else {
758                            /* Consecutive keyframes case:
759                             * Flush immediatly the keyframe overflow and reset keyframe
760                             * overflow */
761                            rc->overflow += rc->KFoverflow;
762                            rc->KFoverflow = 0;
763                            rc->KFoverflow_partial = 0;
764                    }
765                    rc->KF_idx++;
766            } else {
767                    /* Accumulate the frame overflow */
768                    rc->overflow += s->desired_length - data->length;
769    
770                    /* Distribute part of the keyframe overflow */
771                    rc->overflow += rc->KFoverflow_partial;
772    
773                    /* Don't forget to substract that same amount from the total keyframe
774                     * overflow */
775                    rc->KFoverflow -= rc->KFoverflow_partial;
776            }
777    
778            rc->overflow += s->error = s->desired_length - data->length;
779            rc->real_total += data->length;
780    
781            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",
782                            data->frame_num,
783                            frame_type[data->type-1],
784                            data->quant,
785                            s->length,
786                            s->scaled_length,
787                            s->desired_length,
788                            s->desired_length - s->error,
789                            -s->error,
790                            rc->overflow);
791    
792            return(0);
793    }
794    
795    /*****************************************************************************
796     * Helper functions definition
797     ****************************************************************************/
798    
799    /* Default buffer size for reading lines */
800    #define BUF_SZ   1024
801    
802    /* Helper functions for reading/parsing the stats file */
803    static char *skipspaces(char *string);
804    static int iscomment(char *string);
805    static char *readline(FILE *f);
806    
807    /* This function counts the number of frame entries in the stats file
808     * It also counts the number of I Frames */
809    static int
810    statsfile_count_frames(rc_2pass2_t * rc, char * filename)
811    {
812            FILE * f;
813            char *line;
814            int lines;
815    
816            rc->num_frames = 0;
817            rc->num_keyframes = 0;
818    
819            if ((f = fopen(filename, "rb")) == NULL)
820                    return(-1);
821    
822            lines = 0;
823            while ((line = readline(f)) != NULL) {
824    
825                    char *ptr;
826                    char type;
827                    int fields;
828    
829                    lines++;
830    
831                    /* We skip spaces */
832                    ptr = skipspaces(line);
833    
834                    /* Skip coment lines or empty lines */
835                    if(iscomment(ptr) || *ptr == '\0') {
836                            free(line);
837                            continue;
838                    }
839    
840                    /* Read the stat line from buffer */
841                    fields = sscanf(ptr, "%c", &type);
842    
843                    /* Valid stats files have at least 6 fields */
844                    if (fields == 1) {
845                            switch(type) {
846                            case 'i':
847                            case 'I':
848                                    rc->num_keyframes++;
849                            case 'p':
850                            case 'P':
851                            case 'b':
852                            case 'B':
853                            case 's':
854                            case 'S':
855                                    rc->num_frames++;
856                                    break;
857                            default:
858                                    DPRINTF(XVID_DEBUG_RC,
859                                                    "[xvid rc] -- WARNING: L%d unknown frame type used (%c).\n",
860                                                    lines, type);
861                            }
862                    } else {
863                                    DPRINTF(XVID_DEBUG_RC,
864                                                    "[xvid rc] -- WARNING: L%d misses some stat fields (%d).\n",
865                                                    lines, 6-fields);
866                    }
867    
868                    /* Free the line buffer */
869                    free(line);
870            }
871    
872            /* We are done with the file */
873            fclose(f);
874    
875            return(0);
876    }
877    
878    /* open stats file(s) and read into rc->stats array */
879    static int
880    statsfile_load(rc_2pass2_t *rc, char * filename)
881    {
882            FILE * f;
883            int processed_entries;
884    
885            /* Opens the file */
886            if ((f = fopen(filename, "rb"))==NULL)
887                    return(-1);
888    
889            processed_entries = 0;
890            while(processed_entries < rc->num_frames) {
891                    char type;
892                    int fields;
893                    twopass_stat_t * s = &rc->stats[processed_entries];
894                    char *line, *ptr;
895    
896                    /* Read the line from the file */
897                    if((line = readline(f)) == NULL)
898                            break;
899    
900                    /* We skip spaces */
901                    ptr = skipspaces(line);
902    
903                    /* Skip comment lines or empty lines */
904                    if(iscomment(ptr) || *ptr == '\0') {
905                            free(line);
906                            continue;
907                    }
908    
909                    /* Reset this field that is optional */
910                    s->scaled_length = 0;
911    
912                    /* Convert the fields */
913                    fields = sscanf(ptr,
914                                                    "%c %d %d %d %d %d %d\n",
915                                                    &type,
916                                                    &s->quant,
917                                                    &s->blks[0], &s->blks[1], &s->blks[2],
918                                                    &s->length,
919                                                    &s->scaled_length);
920    
921                    /* Free line buffer, we don't need it anymore */
922                    free(line);
923    
924                    /* Fail silently, this has probably been warned in
925                     * statsfile_count_frames */
926                    if(fields != 6 && fields != 7)
927                            continue;
928    
929                    /* Convert frame type */
930                    switch(type) {
931                    case 'i':
932                    case 'I':
933                            s->type = XVID_TYPE_IVOP;
934                            break;
935                    case 'p':
936                    case 'P':
937                    case 's':
938                    case 'S':
939                            s->type = XVID_TYPE_PVOP;
940                            break;
941                    case 'b':
942                    case 'B':
943                            s->type = XVID_TYPE_BVOP;
944                            break;
945                    default:
946                            /* Same as before, fail silently */
947                            continue;
948                    }
949    
950                    /* Ok it seems it's been processed correctly */
951                    processed_entries++;
952            }
953    
954            /* Close the file */
955            fclose(f);
956    
957            return(0);
958    }
959    
960    /* pre-process the statistics data
961     * - for each type, count, tot_length, min_length, max_length
962     * - set keyframes_locations */
963    static void
964    first_pass_stats_prepare_data(rc_2pass2_t * rc)
965    {
966            int i,j;
967    
968            /* *rc fields initialization
969             * NB: INT_MAX and INT_MIN are used in order to be immediately replaced
970             *     with real values of the 1pass */
971            for (i=0; i<3; i++) {
972                    rc->count[i]=0;
973                    rc->tot_length[i] = 0;
974                    rc->min_length[i] = INT_MAX;
975            }
976    
977            rc->max_length = INT_MIN;
978    
979            /* Loop through all frames and find/compute all the stuff this function
980             * is supposed to do */
981            for (i=j=0; i<rc->num_frames; i++) {
982                    twopass_stat_t * s = &rc->stats[i];
983    
984                    rc->count[s->type-1]++;
985                    rc->tot_length[s->type-1] += s->length;
986    
987                    if (s->length < rc->min_length[s->type-1]) {
988                            rc->min_length[s->type-1] = s->length;
989                    }
990    
991                    if (s->length > rc->max_length) {
992                            rc->max_length = s->length;
993                    }
994    
995                    if (s->type == XVID_TYPE_IVOP) {
996                            rc->keyframe_locations[j] = i;
997                            j++;
998                    }
999            }
1000    
1001            /* NB:
1002             * The "per sequence" overflow system considers a natural sequence to be
1003             * formed by all frames between two iframes, so if we want to make sure
1004             * the system does not go nuts during last sequence, we force the last
1005             * frame to appear in the keyframe locations array. */
1006            rc->keyframe_locations[j] = i;
1007    
1008            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Min 1st pass IFrame length: %d\n", rc->min_length[0]);
1009            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Min 1st pass PFrame length: %d\n", rc->min_length[1]);
1010            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Min 1st pass BFrame length: %d\n", rc->min_length[2]);
1011    }
1012    
1013    /* calculate zone weight "center" */
1014    static void
1015    zone_process(rc_2pass2_t *rc, const xvid_plg_create_t * create)
1016    {
1017            int i,j;
1018            int n = 0;
1019    
1020            rc->avg_weight = 0.0;
1021            rc->tot_quant = 0;
1022    
1023    
1024            if (create->num_zones == 0) {
1025                    for (j = 0; j < rc->num_frames; j++) {
1026                            rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;
1027                            rc->stats[j].weight = 1.0;
1028                    }
1029                    rc->avg_weight += rc->num_frames * 1.0;
1030                    n += rc->num_frames;
1031            }
1032    
1033    
1034            for(i=0; i < create->num_zones; i++) {
1035    
1036                    int next = (i+1<create->num_zones) ? create->zones[i+1].frame : rc->num_frames;
1037    
1038                    if (i==0 && create->zones[i].frame > 0) {
1039                            for (j = 0; j < create->zones[i].frame && j < rc->num_frames; j++) {
1040                                    rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;
1041                                    rc->stats[j].weight = 1.0;
1042                            }
1043                            rc->avg_weight += create->zones[i].frame * 1.0;
1044                            n += create->zones[i].frame;
1045                    }
1046    
1047                    if (create->zones[i].mode == XVID_ZONE_WEIGHT) {
1048                            for (j = create->zones[i].frame; j < next && j < rc->num_frames; j++ ) {
1049                                    rc->stats[j].zone_mode = XVID_ZONE_WEIGHT;
1050                                    rc->stats[j].weight = (double)create->zones[i].increment / (double)create->zones[i].base;
1051                            }
1052                            next -= create->zones[i].frame;
1053                            rc->avg_weight += (double)(next * create->zones[i].increment) / (double)create->zones[i].base;
1054                            n += next;
1055                    }else{  /* XVID_ZONE_QUANT */
1056                            for (j = create->zones[i].frame; j < next && j < rc->num_frames; j++ ) {
1057                                    rc->stats[j].zone_mode = XVID_ZONE_QUANT;
1058                                    rc->stats[j].weight = (double)create->zones[i].increment / (double)create->zones[i].base;
1059                                    rc->tot_quant += rc->stats[j].length;
1060                            }
1061                    }
1062            }
1063            rc->avg_weight = n>0 ? rc->avg_weight/n : 1.0;
1064    
1065            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- center_weight:%f (for %d frames)  fixed_bytes:%d\n", rc->avg_weight, n, rc->tot_quant);
1066    }
1067    
1068    
1069    /* scale the curve */
1070    static void
1071    first_pass_scale_curve_internal(rc_2pass2_t *rc)
1072    {
1073            int64_t target;
1074            int64_t pass1_length;
1075            double scaler;
1076            int i, num_MBs;
1077    
1078            /* We remove the bytes used by the fixed quantizer zones
1079             * ToDo: this approach is flawed, the same amount of bytes is removed from
1080             *       target and first pass data, this has no sense, zone_process should
1081             *       give us two results one for unscaled data (1pass) and the other
1082             *       one for scaled data and we should then write:
1083             *       target = rc->target - rc->tot_quant_scaled;
1084             *       pass1_length = rc->i+p+b - rc->tot_quant_firstpass */
1085            target = rc->target - rc->tot_quant;
1086    
1087            /* Do the same for the first pass data */
1088            pass1_length  = rc->tot_length[XVID_TYPE_IVOP-1];
1089            pass1_length += rc->tot_length[XVID_TYPE_PVOP-1];
1090            pass1_length += rc->tot_length[XVID_TYPE_BVOP-1];
1091            pass1_length -= rc->tot_quant;
1092    
1093            /* Let's compute a linear scaler in order to perform curve scaling */
1094            scaler = (double)target / (double)pass1_length;
1095    
1096            if (target <= 0 || pass1_length <= 0 || target >= pass1_length) {
1097                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- WARNING: Undersize detected before correction\n");
1098                    scaler = 1.0;
1099            }
1100    
1101            /* Compute min frame lengths (for each frame type) according to the number
1102             * of MBs. We sum all block type counters of frame 0, this gives us the
1103             * number of MBs.
1104             *
1105             * We compare these hardcoded values with observed values in first pass
1106             * (determined in pre_process0).Then we keep the real minimum. */
1107    
1108            /* Number of MBs */
1109            num_MBs  = rc->stats[0].blks[0];
1110            num_MBs += rc->stats[0].blks[1];
1111            num_MBs += rc->stats[0].blks[2];
1112    
1113            /* Minimum for I frames */
1114            if(rc->min_length[XVID_TYPE_IVOP-1] > ((num_MBs*22) + 240) / 8)
1115                    rc->min_length[XVID_TYPE_IVOP-1] = ((num_MBs*22) + 240) / 8;
1116    
1117            /* Minimum for P/S frames */
1118            if(rc->min_length[XVID_TYPE_PVOP-1] > ((num_MBs) + 88)  / 8)
1119                    rc->min_length[XVID_TYPE_PVOP-1] = ((num_MBs) + 88)  / 8;
1120    
1121            /* Minimum for B frames */
1122            if(rc->min_length[XVID_TYPE_BVOP-1] > 8)
1123                    rc->min_length[XVID_TYPE_BVOP-1] = 8;
1124    
1125            /* Perform an initial scale pass.
1126             *
1127             * If a frame size is scaled underneath our hardcoded minimums, then we
1128             * force the frame size to the minimum, and deduct the original & scaled
1129             * frame length from the original and target total lengths */
1130            for (i=0; i<rc->num_frames; i++) {
1131                    twopass_stat_t * s = &rc->stats[i];
1132                    int len;
1133    
1134                    /* No need to scale frame length for which a specific quantizer is
1135                     * specified thanks to zones */
1136                    if (s->zone_mode == XVID_ZONE_QUANT) {
1137                            s->scaled_length = s->length;
1138                            continue;
1139                    }
1140    
1141                    /* Compute the scaled length */
1142                    len = (int)((double)s->length * scaler * s->weight / rc->avg_weight);
1143    
1144                    /* Compare with the computed minimum */
1145                    if (len < rc->min_length[s->type-1]) {
1146                            /* This is a 'forced size' frame, set its frame size to the
1147                             * computed minimum */
1148                            s->scaled_length = rc->min_length[s->type-1];
1149    
1150                            /* Remove both scaled and original size from their respective
1151                             * total counters, as we prepare a second pass for 'regular'
1152                             * frames */
1153                            target -= s->scaled_length;
1154                            pass1_length -= s->length;
1155                    } else {
1156                            /* Do nothing for now, we'll scale this later */
1157                            s->scaled_length = 0;
1158                    }
1159            }
1160    
1161            /* The first pass on data substracted all 'forced size' frames from the
1162             * total counters. Now, it's possible to scale the 'regular' frames. */
1163    
1164            /* Scaling factor for 'regular' frames */
1165            scaler = (double)target / (double)pass1_length;
1166    
1167            /* Detect undersizing */
1168            if (target <= 0 || pass1_length <= 0 || target >= pass1_length) {
1169                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- WARNING: Undersize detected after correction\n");
1170                    scaler = 1.0;
1171            }
1172    
1173            /* Do another pass with the new scaler */
1174            for (i=0; i<rc->num_frames; i++) {
1175                    twopass_stat_t * s = &rc->stats[i];
1176    
1177                    /* Ignore frame with forced frame sizes */
1178                    if (s->scaled_length == 0)
1179                            s->scaled_length = (int)((double)s->length * scaler * s->weight / rc->avg_weight);
1180            }
1181    
1182            /* Job done */
1183            return;
1184    }
1185    
1186    /* Apply all user settings to the scaled curve
1187     * This implies:
1188     *   keyframe boosting
1189     *   high/low compression */
1190    static void
1191    scaled_curve_apply_advanced_parameters(rc_2pass2_t * rc)
1192    {
1193            int i;
1194            uint64_t ivop_boost_total;
1195    
1196            /* Reset the rate controller (per frame type) total byte counters */
1197            for (i=0; i<3; i++) rc->tot_scaled_length[i] = 0;
1198    
1199            /* Compute total bytes for each frame type */
1200            for (i=0; i<rc->num_frames;i++) {
1201                    twopass_stat_t *s = &rc->stats[i];
1202                    rc->tot_scaled_length[s->type-1] += s->scaled_length;
1203            }
1204    
1205            /* First we compute the total amount of bits needed, as being described by
1206             * the scaled distribution. During this pass over the complete stats data,
1207             * we see how much bits two user settings will get/give from/to p&b frames:
1208             *  - keyframe boosting
1209             *  - keyframe distance penalty */
1210            rc->KF_idx = 0;
1211            ivop_boost_total = 0;
1212            for (i=0; i<rc->num_frames; i++) {
1213                    twopass_stat_t * s = &rc->stats[i];
1214    
1215                    /* Some more work is needed for I frames */
1216                    if (s->type == XVID_TYPE_IVOP) {
1217                            int penalty_distance;
1218                            int ivop_boost;
1219    
1220                            /* Accumulate bytes needed for keyframe boosting */
1221                            ivop_boost = s->scaled_length*rc->param.keyframe_boost/100;
1222    
1223                            if (rc->KF_idx) {
1224                                    /* Minimum keyframe distance penalties */
1225                                    penalty_distance  = rc->param.min_key_interval;
1226                                    penalty_distance -= rc->keyframe_locations[rc->KF_idx];
1227                                    penalty_distance += rc->keyframe_locations[rc->KF_idx-1];
1228    
1229                                    /* Ah ah ! guilty keyframe, you're under arrest ! */
1230                                    if (penalty_distance > 0)
1231                                             ivop_boost -= (s->scaled_length + ivop_boost)*penalty_distance*rc->param.kfreduction/100;
1232                            }
1233    
1234                            /* If the frame size drops under the minimum length, then cap ivop_boost */
1235                            if (ivop_boost + s->scaled_length < rc->min_length[XVID_TYPE_IVOP-1])
1236                                    ivop_boost = rc->min_length[XVID_TYPE_IVOP-1] - s->scaled_length;
1237    
1238                            /* Accumulate the ivop boost */
1239                            ivop_boost_total += ivop_boost;
1240    
1241                            /* Don't forget to update the keyframe index */
1242                            rc->KF_idx++;
1243                    }
1244            }
1245    
1246            /* Initialize the IBoost tax ratio for P/S/B frames
1247             *
1248             * This ratio has to be applied to p/b/s frames in order to reserve
1249             * additional bits for keyframes (keyframe boosting) or if too much
1250             * keyframe distance is applied, bits retrieved from the keyframes.
1251             *
1252             * ie pb_length *= rc->pb_iboost_tax_ratio;
1253             *
1254             *    gives the ideal length of a p/b frame */
1255    
1256            /* Compute the total length of p/b/s frames (temporary storage into
1257             * movie_curve) */
1258            rc->pb_iboost_tax_ratio  = (double)rc->tot_scaled_length[XVID_TYPE_PVOP-1];
1259            rc->pb_iboost_tax_ratio += (double)rc->tot_scaled_length[XVID_TYPE_BVOP-1];
1260    
1261            /* Compute the ratio described above
1262             *     taxed_total = sum(0, n, tax*scaled_length)
1263             * <=> taxed_total = tax.sum(0, n, tax*scaled_length)
1264             * <=> tax = taxed_total / original_total */
1265            rc->pb_iboost_tax_ratio =
1266                    (rc->pb_iboost_tax_ratio - ivop_boost_total) /
1267                    rc->pb_iboost_tax_ratio;
1268    
1269            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- IFrame boost tax ratio:%.2f\n",
1270                            rc->pb_iboost_tax_ratio);
1271    
1272            /* Compute the average size of frames per frame type */
1273            for(i=0; i<3; i++) {
1274                    /* Special case for missing type or weird case */
1275                    if (rc->count[i] == 0 || rc->pb_iboost_tax_ratio == 0) {
1276                            rc->avg_length[i] = 1;
1277                    } else {
1278                            rc->avg_length[i] = rc->tot_scaled_length[i];
1279    
1280                            if (i == (XVID_TYPE_IVOP-1)) {
1281                                    /* I Frames total has to be added the boost total */
1282                                    rc->avg_length[i] += ivop_boost_total;
1283                            } else {
1284                                    /* P/B frames has to taxed */
1285                                    rc->avg_length[i] *= rc->pb_iboost_tax_ratio;
1286                            }
1287    
1288                            /* Finally compute the average frame size */
1289                            rc->avg_length[i] /= (double)rc->count[i];
1290                    }
1291            }
1292    
1293            /* Assymetric curve compression */
1294            if (rc->param.curve_compression_high || rc->param.curve_compression_low) {
1295                    double symetric_total;
1296                    double assymetric_delta_total;
1297    
1298                    /* Like I frame boosting, assymetric curve compression modifies the total
1299                     * amount of needed bits, we must compute the ratio so we can prescale
1300                     lengths */
1301                    symetric_total = 0;
1302                    assymetric_delta_total = 0;
1303                    for (i=0; i<rc->num_frames; i++) {
1304                            double assymetric_delta;
1305                            double dbytes;
1306                            twopass_stat_t * s = &rc->stats[i];
1307    
1308                            /* I Frames are not concerned by assymetric scaling */
1309                            if (s->type == XVID_TYPE_IVOP)
1310                                    continue;
1311    
1312                            /* During the real run, we would have to apply the iboost tax */
1313                            dbytes = s->scaled_length * rc->pb_iboost_tax_ratio;
1314    
1315                            /* Update the symmetric curve compression total */
1316                            symetric_total += dbytes;
1317    
1318                            /* Apply assymetric curve compression */
1319                            if (dbytes > rc->avg_length[s->type-1])
1320                                    assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * (double)rc->param.curve_compression_high / 100.0f;
1321                            else
1322                                    assymetric_delta = (rc->avg_length[s->type-1] - dbytes) * (double)rc->param.curve_compression_low  / 100.0f;
1323    
1324                            /* Cap to the minimum frame size if needed */
1325                            if (dbytes + assymetric_delta < rc->min_length[s->type-1])
1326                                    assymetric_delta = rc->min_length[s->type-1] - dbytes;
1327    
1328                            /* Accumulate after assymetric curve compression */
1329                            assymetric_delta_total += assymetric_delta;
1330                    }
1331    
1332                    /* Compute the tax that all p/b frames have to pay in order to respect the
1333                     * bit distribution changes that the assymetric compression curve imposes
1334                     * We want assymetric_total = sum(0, n-1, tax.scaled_length)
1335                     *      ie assymetric_total = ratio.sum(0, n-1, scaled_length)
1336                     *         ratio = assymetric_total / symmetric_total */
1337                    rc->assymetric_tax_ratio = ((double)symetric_total - (double)assymetric_delta_total) / (double)symetric_total;
1338            } else {
1339                    rc->assymetric_tax_ratio = 1.0f;
1340            }
1341    
1342            DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- Assymetric tax ratio:%.2f\n", rc->assymetric_tax_ratio);
1343    
1344            /* Last bits that need to be reset */
1345            rc->overflow = 0;
1346            rc->KFoverflow = 0;
1347            rc->KFoverflow_partial = 0;
1348            rc->KF_idx = 0;
1349            rc->desired_total = 0;
1350            rc->real_total = 0;
1351    
1352            /* Job done */
1353            return;
1354    }
1355    
1356    /*****************************************************************************
1357     * Still more low level stuff (nothing to do with stats treatment)
1358     ****************************************************************************/
1359    
1360    /* This function returns an allocated string containing a complete line read
1361     * from the file starting at the current position */
1362    static char *
1363    readline(FILE *f)
1364    {
1365            char *buffer = NULL;
1366            int buffer_size = 0;
1367            int pos = 0;
1368    
1369            do {
1370                    int c;
1371    
1372                    /* Read a character from the stream */
1373                    c = fgetc(f);
1374    
1375                    /* Is that EOF or new line ? */
1376                    if(c == EOF || c == '\n')
1377                            break;
1378    
1379                    /* Do we have to update buffer ? */
1380                    if(pos >= buffer_size - 1) {
1381                            buffer_size += BUF_SZ;
1382                            buffer = (char*)realloc(buffer, buffer_size);
1383                            if (buffer == NULL)
1384                                    return(NULL);
1385                    }
1386    
1387                    buffer[pos] = c;
1388                    pos++;
1389            } while(1);
1390    
1391            /* Read \n or EOF */
1392            if (buffer == NULL) {
1393                    /* EOF, so we reached the end of the file, return NULL */
1394                    if(feof(f))
1395                            return(NULL);
1396    
1397                    /* Just an empty line with just a newline, allocate a 1 byte buffer to
1398                     * store a zero length string */
1399                    buffer = (char*)malloc(1);
1400                    if(buffer == NULL)
1401                            return(NULL);
1402            }
1403    
1404            /* Zero terminated string */
1405            buffer[pos] = '\0';
1406    
1407            return(buffer);
1408    }
1409    
1410    /* This function returns a pointer to the first non space char in the given
1411     * string */
1412    static char *
1413    skipspaces(char *string)
1414    {
1415            const char spaces[] =
1416                    {
1417                            ' ','\t','\0'
1418                    };
1419            const char *spacechar = spaces;
1420    
1421            if (string == NULL) return(NULL);
1422    
1423            while (*string != '\0') {
1424                    /* Test against space chars */
1425                    while (*spacechar != '\0') {
1426                            if (*string == *spacechar) {
1427                                    string++;
1428                                    spacechar = spaces;
1429                                    break;
1430                            }
1431                            spacechar++;
1432                    }
1433    
1434                    /* No space char */
1435                    if (*spacechar == '\0') return(string);
1436            }
1437    
1438            return(string);
1439    }
1440    
1441    /* This function returns a boolean that tells if the string is only a
1442     * comment */
1443    static int
1444    iscomment(char *string)
1445    {
1446            const char comments[] =
1447                    {
1448                            '#',';', '%', '\0'
1449                    };
1450            const char *cmtchar = comments;
1451            int iscomment = 0;
1452    
1453            if (string == NULL) return(1);
1454    
1455            string = skipspaces(string);
1456    
1457            while(*cmtchar != '\0') {
1458                    if(*string == *cmtchar) {
1459                            iscomment = 1;
1460                            break;
1461                    }
1462                    cmtchar++;
1463            }
1464    
1465            return(iscomment);
1466    }
1467    
1468    #if 0
1469    static void
1470    stats_print(rc_2pass2_t * rc)
1471    {
1472            int i;
1473            const char frame_type[4] = { 'i', 'p', 'b', 's'};
1474    
1475            for (i=0; i<rc->num_frames; i++) {
1476                    twopass_stat_t *s = &rc->stats[i];
1477                    DPRINTF(XVID_DEBUG_RC, "[xvid rc] -- frame:%d type:%c quant:%d stats:%d scaled:%d desired:%d actual:%d overflow(%c):%.2f\n",
1478                                    i, frame_type[s->type-1], -1, s->length, s->scaled_length,
1479                                    s->desired_length, -1, frame_type[s->type-1], -1.0f);
1480            }
1481    }
1482    #endif
Legend:
Removed from v.1.1  
changed lines
  Added in v.1.1.2.27
No admin address has been configured
 ViewVC Help
Powered by ViewVC 1.0.4