1 |
/****************************************************************************** |
/***************************************************************************** |
2 |
* * |
* |
3 |
* This file is part of XviD, a free MPEG-4 video encoder/decoder * |
* XVID MPEG-4 VIDEO CODEC |
4 |
* * |
* - Bitstream reader/writer inlined functions and constants- |
5 |
* XviD is an implementation of a part of one or more MPEG-4 Video tools * |
* |
6 |
* as specified in ISO/IEC 14496-2 standard. Those intending to use this * |
* Copyright (C) 2001-2003 Peter Ross <pross@xvid.org> |
7 |
* software module in hardware or software products are advised that its * |
* |
8 |
* use may infringe existing patents or copyrights, and any such use * |
* This program is free software ; you can redistribute it and/or modify |
9 |
* would be at such party's own risk. The original developer of this * |
* it under the terms of the GNU General Public License as published by |
10 |
* software module and his/her company, and subsequent editors and their * |
* the Free Software Foundation ; either version 2 of the License, or |
11 |
* companies, will have no liability for use of this software or * |
* (at your option) any later version. |
12 |
* modifications or derivatives thereof. * |
* |
13 |
* * |
* This program is distributed in the hope that it will be useful, |
14 |
* XviD is free software; you can redistribute it and/or modify it * |
* but WITHOUT ANY WARRANTY ; without even the implied warranty of |
15 |
* under the terms of the GNU General Public License as published by * |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
16 |
* the Free Software Foundation; either version 2 of the License, or * |
* GNU General Public License for more details. |
17 |
* (at your option) any later version. * |
* |
18 |
* * |
* You should have received a copy of the GNU General Public License |
19 |
* XviD is distributed in the hope that it will be useful, but * |
* along with this program ; if not, write to the Free Software |
20 |
* WITHOUT ANY WARRANTY; without even the implied warranty of * |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
21 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
* |
22 |
* GNU General Public License for more details. * |
* $Id$ |
23 |
* * |
* |
24 |
* You should have received a copy of the GNU General Public License * |
****************************************************************************/ |
|
* along with this program; if not, write to the Free Software * |
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * |
|
|
* * |
|
|
******************************************************************************/ |
|
|
|
|
|
/****************************************************************************** |
|
|
* * |
|
|
* bitstream.h * |
|
|
* * |
|
|
* Copyright (C) 2001 - Peter Ross <pross@cs.rmit.edu.au> * |
|
|
* * |
|
|
* For more information visit the XviD homepage: http://www.xvid.org * |
|
|
* * |
|
|
******************************************************************************/ |
|
|
|
|
|
/****************************************************************************** |
|
|
* * |
|
|
* Revision history: * |
|
|
* * |
|
|
* 26.03.2002 interlacing support - modified putvol/vopheaders paramters |
|
|
* 04.03.2002 putbits speedup (Isibaar) * |
|
|
* 03.03.2002 merged BITREADER and BITWRITER (Isibaar) * |
|
|
* 16.12.2001 inital version * |
|
|
* * |
|
|
******************************************************************************/ |
|
25 |
|
|
26 |
#ifndef _BITSTREAM_H_ |
#ifndef _BITSTREAM_H_ |
27 |
#define _BITSTREAM_H_ |
#define _BITSTREAM_H_ |
30 |
#include "../decoder.h" |
#include "../decoder.h" |
31 |
#include "../encoder.h" |
#include "../encoder.h" |
32 |
|
|
33 |
// comment any #defs we dont use |
|
34 |
|
/***************************************************************************** |
35 |
|
* Constants |
36 |
|
****************************************************************************/ |
37 |
|
|
38 |
|
/* comment any #defs we dont use */ |
39 |
|
|
40 |
#define VIDOBJ_START_CODE 0x00000100 /* ..0x0000011f */ |
#define VIDOBJ_START_CODE 0x00000100 /* ..0x0000011f */ |
41 |
#define VIDOBJLAY_START_CODE 0x00000120 /* ..0x0000012f */ |
#define VIDOBJLAY_START_CODE 0x00000120 /* ..0x0000012f */ |
43 |
#define VISOBJSEQ_STOP_CODE 0x000001b1 /* ??? */ |
#define VISOBJSEQ_STOP_CODE 0x000001b1 /* ??? */ |
44 |
#define USERDATA_START_CODE 0x000001b2 |
#define USERDATA_START_CODE 0x000001b2 |
45 |
#define GRPOFVOP_START_CODE 0x000001b3 |
#define GRPOFVOP_START_CODE 0x000001b3 |
46 |
//#define VIDSESERR_ERROR_CODE 0x000001b4 |
/*#define VIDSESERR_ERROR_CODE 0x000001b4 */ |
47 |
#define VISOBJ_START_CODE 0x000001b5 |
#define VISOBJ_START_CODE 0x000001b5 |
48 |
//#define SLICE_START_CODE 0x000001b7 |
#define VOP_START_CODE 0x000001b6 |
49 |
//#define EXT_START_CODE 0x000001b8 |
/*#define STUFFING_START_CODE 0x000001c3 */ |
50 |
|
|
51 |
|
|
52 |
#define VISOBJ_TYPE_VIDEO 1 |
#define VISOBJ_TYPE_VIDEO 1 |
53 |
//#define VISOBJ_TYPE_STILLTEXTURE 2 |
/*#define VISOBJ_TYPE_STILLTEXTURE 2 */ |
54 |
//#define VISOBJ_TYPE_MESH 3 |
/*#define VISOBJ_TYPE_MESH 3 */ |
55 |
//#define VISOBJ_TYPE_FBA 4 |
/*#define VISOBJ_TYPE_FBA 4 */ |
56 |
//#define VISOBJ_TYPE_3DMESH 5 |
/*#define VISOBJ_TYPE_3DMESH 5 */ |
57 |
|
|
58 |
|
|
59 |
#define VIDOBJLAY_TYPE_SIMPLE 1 |
#define VIDOBJLAY_TYPE_SIMPLE 1 |
60 |
//#define VIDOBJLAY_TYPE_SIMPLE_SCALABLE 2 |
/*#define VIDOBJLAY_TYPE_SIMPLE_SCALABLE 2 */ |
61 |
#define VIDOBJLAY_TYPE_CORE 3 |
/*#define VIDOBJLAY_TYPE_CORE 3 */ |
62 |
#define VIDOBJLAY_TYPE_MAIN 4 |
/*#define VIDOBJLAY_TYPE_MAIN 4 */ |
63 |
|
/*#define VIDOBJLAY_TYPE_NBIT 5 */ |
64 |
|
/*#define VIDOBJLAY_TYPE_ANIM_TEXT 6 */ |
65 |
//#define VIDOBJLAY_AR_SQUARE 1 |
/*#define VIDOBJLAY_TYPE_ANIM_MESH 7 */ |
66 |
//#define VIDOBJLAY_AR_625TYPE_43 2 |
/*#define VIDOBJLAY_TYPE_SIMPLE_FACE 8 */ |
67 |
//#define VIDOBJLAY_AR_525TYPE_43 3 |
/*#define VIDOBJLAY_TYPE_STILL_SCALABLE 9 */ |
68 |
//#define VIDOBJLAY_AR_625TYPE_169 8 |
#define VIDOBJLAY_TYPE_ART_SIMPLE 10 |
69 |
//#define VIDOBJLAY_AR_525TYPE_169 9 |
/*#define VIDOBJLAY_TYPE_CORE_SCALABLE 11 */ |
70 |
|
/*#define VIDOBJLAY_TYPE_ACE 12 */ |
71 |
|
/*#define VIDOBJLAY_TYPE_ADVANCED_SCALABLE_TEXTURE 13 */ |
72 |
|
/*#define VIDOBJLAY_TYPE_SIMPLE_FBA 14 */ |
73 |
|
/*#define VIDEOJLAY_TYPE_SIMPLE_STUDIO 15*/ |
74 |
|
/*#define VIDEOJLAY_TYPE_CORE_STUDIO 16*/ |
75 |
|
#define VIDOBJLAY_TYPE_ASP 17 |
76 |
|
/*#define VIDOBJLAY_TYPE_FGS 18*/ |
77 |
|
|
78 |
|
|
79 |
|
/*#define VIDOBJLAY_AR_SQUARE 1 */ |
80 |
|
/*#define VIDOBJLAY_AR_625TYPE_43 2 */ |
81 |
|
/*#define VIDOBJLAY_AR_525TYPE_43 3 */ |
82 |
|
/*#define VIDOBJLAY_AR_625TYPE_169 8 */ |
83 |
|
/*#define VIDOBJLAY_AR_525TYPE_169 9 */ |
84 |
#define VIDOBJLAY_AR_EXTPAR 15 |
#define VIDOBJLAY_AR_EXTPAR 15 |
85 |
|
|
86 |
|
|
89 |
#define VIDOBJLAY_SHAPE_BINARY_ONLY 2 |
#define VIDOBJLAY_SHAPE_BINARY_ONLY 2 |
90 |
#define VIDOBJLAY_SHAPE_GRAYSCALE 3 |
#define VIDOBJLAY_SHAPE_GRAYSCALE 3 |
91 |
|
|
92 |
#define VO_START_CODE 0x8 |
|
93 |
#define VOL_START_CODE 0x12 |
#define SPRITE_NONE 0 |
94 |
#define VOP_START_CODE 0x1b6 |
#define SPRITE_STATIC 1 |
95 |
|
#define SPRITE_GMC 2 |
96 |
|
|
97 |
|
|
98 |
|
|
99 |
#define READ_MARKER() BitstreamSkip(bs, 1) |
#define READ_MARKER() BitstreamSkip(bs, 1) |
100 |
#define WRITE_MARKER() BitstreamPutBit(bs, 1) |
#define WRITE_MARKER() BitstreamPutBit(bs, 1) |
101 |
|
|
102 |
// vop coding types |
/* vop coding types */ |
103 |
// intra, prediction, backward, sprite, not_coded |
/* intra, prediction, backward, sprite, not_coded */ |
104 |
#define I_VOP 0 |
#define I_VOP 0 |
105 |
#define P_VOP 1 |
#define P_VOP 1 |
106 |
#define B_VOP 2 |
#define B_VOP 2 |
107 |
#define S_VOP 3 |
#define S_VOP 3 |
108 |
#define N_VOP 4 |
#define N_VOP 4 |
109 |
|
|
110 |
|
/* resync-specific */ |
111 |
// header stuff |
#define NUMBITS_VP_RESYNC_MARKER 17 |
112 |
int BitstreamReadHeaders(Bitstream * bs, DECODER * dec, uint32_t * rounding, |
#define RESYNC_MARKER 1 |
113 |
uint32_t * quant, uint32_t * fcode_forward, uint32_t * fcode_backward, uint32_t * intra_dc_threshold); |
|
114 |
|
|
115 |
|
/***************************************************************************** |
116 |
|
* Prototypes |
117 |
|
****************************************************************************/ |
118 |
|
|
119 |
|
int read_video_packet_header(Bitstream *bs, |
120 |
|
DECODER * dec, |
121 |
|
const int addbits, |
122 |
|
int *quant, |
123 |
|
int *fcode_forward, |
124 |
|
int *fcode_backward, |
125 |
|
int *intra_dc_threshold); |
126 |
|
|
127 |
|
/* header stuff */ |
128 |
|
int BitstreamReadHeaders(Bitstream * bs, |
129 |
|
DECODER * dec, |
130 |
|
uint32_t * rounding, |
131 |
|
uint32_t * quant, |
132 |
|
uint32_t * fcode_forward, |
133 |
|
uint32_t * fcode_backward, |
134 |
|
uint32_t * intra_dc_threshold, |
135 |
|
WARPPOINTS * gmc_warp); |
136 |
|
|
137 |
|
|
138 |
void BitstreamWriteVolHeader(Bitstream * const bs, |
void BitstreamWriteVolHeader(Bitstream * const bs, |
139 |
const MBParam * pParam, |
const MBParam * pParam, |
140 |
const FRAMEINFO * frame); |
const FRAMEINFO * const frame); |
141 |
|
|
142 |
void BitstreamWriteVopHeader(Bitstream * const bs, |
void BitstreamWriteVopHeader(Bitstream * const bs, |
143 |
const MBParam * pParam, |
const MBParam * pParam, |
144 |
const FRAMEINFO * frame); |
const FRAMEINFO * const frame, |
145 |
|
int vop_coded, |
146 |
|
unsigned int quant); |
147 |
|
|
148 |
|
void BitstreamWriteUserData(Bitstream * const bs, |
149 |
|
const char *data, |
150 |
|
const unsigned int length); |
151 |
|
|
152 |
|
void |
153 |
|
BitstreamWriteEndOfSequence(Bitstream * const bs); |
154 |
|
|
155 |
|
void |
156 |
|
BitstreamWriteGroupOfVopHeader(Bitstream * const bs, |
157 |
|
const MBParam * pParam, |
158 |
|
uint32_t is_closed_gov); |
159 |
|
|
160 |
|
void write_video_packet_header(Bitstream * const bs, |
161 |
|
const MBParam * pParam, |
162 |
|
const FRAMEINFO * const frame, |
163 |
|
int mbnum); |
164 |
|
|
165 |
/* initialise bitstream structure */ |
/* initialise bitstream structure */ |
166 |
|
|
167 |
static void __inline BitstreamInit(Bitstream * const bs, |
static void __inline |
168 |
|
BitstreamInit(Bitstream * const bs, |
169 |
void * const bitstream, |
void * const bitstream, |
170 |
uint32_t length) |
uint32_t length) |
171 |
{ |
{ |
172 |
uint32_t tmp; |
uint32_t tmp; |
173 |
|
size_t bitpos; |
174 |
|
ptr_t adjbitstream = (ptr_t)bitstream; |
175 |
|
|
176 |
bs->start = bs->tail = (uint32_t*)bitstream; |
/* |
177 |
|
* Start the stream on a uint32_t boundary, by rounding down to the |
178 |
|
* previous uint32_t and skipping the intervening bytes. |
179 |
|
*/ |
180 |
|
bitpos = ((sizeof(uint32_t)-1) & (size_t)bitstream); |
181 |
|
adjbitstream = adjbitstream - bitpos; |
182 |
|
bs->start = bs->tail = (uint32_t *) adjbitstream; |
183 |
|
|
184 |
tmp = *(uint32_t *)bitstream; |
tmp = *bs->start; |
185 |
#ifndef ARCH_IS_BIG_ENDIAN |
#ifndef ARCH_IS_BIG_ENDIAN |
186 |
BSWAP(tmp); |
BSWAP(tmp); |
187 |
#endif |
#endif |
188 |
bs->bufa = tmp; |
bs->bufa = tmp; |
189 |
|
|
190 |
tmp = *((uint32_t *)bitstream + 1); |
tmp = *(bs->start + 1); |
191 |
#ifndef ARCH_IS_BIG_ENDIAN |
#ifndef ARCH_IS_BIG_ENDIAN |
192 |
BSWAP(tmp); |
BSWAP(tmp); |
193 |
#endif |
#endif |
194 |
bs->bufb = tmp; |
bs->bufb = tmp; |
195 |
|
|
196 |
bs->buf = 0; |
bs->buf = 0; |
197 |
bs->pos = 0; |
bs->pos = bs->initpos = bitpos*8; |
198 |
bs->length = length; |
bs->length = length; |
199 |
} |
} |
200 |
|
|
201 |
|
|
202 |
/* reset bitstream state */ |
/* reset bitstream state */ |
203 |
|
|
204 |
static void __inline BitstreamReset(Bitstream * const bs) |
static void __inline |
205 |
|
BitstreamReset(Bitstream * const bs) |
206 |
{ |
{ |
207 |
uint32_t tmp; |
uint32_t tmp; |
208 |
|
|
221 |
bs->bufb = tmp; |
bs->bufb = tmp; |
222 |
|
|
223 |
bs->buf = 0; |
bs->buf = 0; |
224 |
bs->pos = 0; |
bs->pos = bs->initpos; |
225 |
} |
} |
226 |
|
|
227 |
|
|
228 |
/* reads n bits from bitstream without changing the stream pos */ |
/* reads n bits from bitstream without changing the stream pos */ |
229 |
|
|
230 |
static uint32_t __inline BitstreamShowBits(Bitstream * const bs, |
static uint32_t __inline |
231 |
|
BitstreamShowBits(Bitstream * const bs, |
232 |
const uint32_t bits) |
const uint32_t bits) |
233 |
{ |
{ |
234 |
int nbit = (bits + bs->pos) - 32; |
int nbit = (bits + bs->pos) - 32; |
235 |
if (nbit > 0) |
|
236 |
{ |
if (nbit > 0) { |
237 |
return ((bs->bufa & (0xffffffff >> bs->pos)) << nbit) | |
return ((bs->bufa & (0xffffffff >> bs->pos)) << nbit) | (bs-> |
238 |
(bs->bufb >> (32 - nbit)); |
bufb >> (32 - |
239 |
} |
nbit)); |
240 |
else |
} else { |
|
{ |
|
241 |
return (bs->bufa & (0xffffffff >> bs->pos)) >> (32 - bs->pos - bits); |
return (bs->bufa & (0xffffffff >> bs->pos)) >> (32 - bs->pos - bits); |
242 |
} |
} |
243 |
} |
} |
245 |
|
|
246 |
/* skip n bits forward in bitstream */ |
/* skip n bits forward in bitstream */ |
247 |
|
|
248 |
static __inline void BitstreamSkip(Bitstream * const bs, const uint32_t bits) |
static __inline void |
249 |
|
BitstreamSkip(Bitstream * const bs, |
250 |
|
const uint32_t bits) |
251 |
{ |
{ |
252 |
bs->pos += bits; |
bs->pos += bits; |
253 |
|
|
254 |
if (bs->pos >= 32) |
if (bs->pos >= 32) { |
|
{ |
|
255 |
uint32_t tmp; |
uint32_t tmp; |
256 |
|
|
257 |
bs->bufa = bs->bufb; |
bs->bufa = bs->bufb; |
266 |
} |
} |
267 |
|
|
268 |
|
|
269 |
|
/* number of bits to next byte alignment */ |
270 |
|
static __inline uint32_t |
271 |
|
BitstreamNumBitsToByteAlign(Bitstream *bs) |
272 |
|
{ |
273 |
|
uint32_t n = (32 - bs->pos) % 8; |
274 |
|
return n == 0 ? 8 : n; |
275 |
|
} |
276 |
|
|
277 |
|
|
278 |
|
/* show nbits from next byte alignment */ |
279 |
|
static __inline uint32_t |
280 |
|
BitstreamShowBitsFromByteAlign(Bitstream *bs, int bits) |
281 |
|
{ |
282 |
|
int bspos = bs->pos + BitstreamNumBitsToByteAlign(bs); |
283 |
|
int nbit = (bits + bspos) - 32; |
284 |
|
|
285 |
|
if (bspos >= 32) { |
286 |
|
return bs->bufb >> (32 - nbit); |
287 |
|
} else if (nbit > 0) { |
288 |
|
return ((bs->bufa & (0xffffffff >> bspos)) << nbit) | (bs-> |
289 |
|
bufb >> (32 - |
290 |
|
nbit)); |
291 |
|
} else { |
292 |
|
return (bs->bufa & (0xffffffff >> bspos)) >> (32 - bspos - bits); |
293 |
|
} |
294 |
|
|
295 |
|
} |
296 |
|
|
297 |
|
|
298 |
|
|
299 |
/* move forward to the next byte boundary */ |
/* move forward to the next byte boundary */ |
300 |
|
|
301 |
static __inline void BitstreamByteAlign(Bitstream * const bs) |
static __inline void |
302 |
|
BitstreamByteAlign(Bitstream * const bs) |
303 |
{ |
{ |
304 |
uint32_t remainder = bs->pos % 8; |
uint32_t remainder = bs->pos % 8; |
305 |
if (remainder) |
|
306 |
{ |
if (remainder) { |
307 |
BitstreamSkip(bs, 8 - remainder); |
BitstreamSkip(bs, 8 - remainder); |
308 |
} |
} |
309 |
} |
} |
311 |
|
|
312 |
/* bitstream length (unit bits) */ |
/* bitstream length (unit bits) */ |
313 |
|
|
314 |
static uint32_t __inline BitstreamPos(const Bitstream * const bs) |
static uint32_t __inline |
315 |
|
BitstreamPos(const Bitstream * const bs) |
316 |
{ |
{ |
317 |
return 8 * ((uint32_t)bs->tail - (uint32_t)bs->start) + bs->pos; |
return((uint32_t)(8*((ptr_t)bs->tail - (ptr_t)bs->start) + bs->pos - bs->initpos)); |
318 |
} |
} |
319 |
|
|
320 |
|
|
321 |
/* flush the bitstream & return length (unit bytes) |
/* |
322 |
NOTE: assumes no futher bitstream functions will be called. |
* flush the bitstream & return length (unit bytes) |
323 |
|
* NOTE: assumes no futher bitstream functions will be called. |
324 |
*/ |
*/ |
325 |
|
|
326 |
static uint32_t __inline BitstreamLength(Bitstream * const bs) |
static uint32_t __inline |
327 |
|
BitstreamLength(Bitstream * const bs) |
328 |
{ |
{ |
329 |
uint32_t len = (uint32_t) bs->tail - (uint32_t) bs->start; |
uint32_t len = (uint32_t)((ptr_t)bs->tail - (ptr_t)bs->start); |
330 |
|
|
331 |
if (bs->pos) |
if (bs->pos) { |
|
{ |
|
332 |
uint32_t b = bs->buf; |
uint32_t b = bs->buf; |
333 |
|
|
334 |
#ifndef ARCH_IS_BIG_ENDIAN |
#ifndef ARCH_IS_BIG_ENDIAN |
335 |
BSWAP(b); |
BSWAP(b); |
336 |
#endif |
#endif |
339 |
len += (bs->pos + 7) / 8; |
len += (bs->pos + 7) / 8; |
340 |
} |
} |
341 |
|
|
342 |
|
/* initpos is always on a byte boundary */ |
343 |
|
if (bs->initpos) |
344 |
|
len -= bs->initpos/8; |
345 |
|
|
346 |
return len; |
return len; |
347 |
} |
} |
348 |
|
|
349 |
|
|
350 |
/* move bitstream position forward by n bits and write out buffer if needed */ |
/* move bitstream position forward by n bits and write out buffer if needed */ |
351 |
|
|
352 |
static void __inline BitstreamForward(Bitstream * const bs, const uint32_t bits) |
static void __inline |
353 |
|
BitstreamForward(Bitstream * const bs, |
354 |
|
const uint32_t bits) |
355 |
{ |
{ |
356 |
bs->pos += bits; |
bs->pos += bits; |
357 |
|
|
358 |
if (bs->pos >= 32) |
if (bs->pos >= 32) { |
|
{ |
|
359 |
uint32_t b = bs->buf; |
uint32_t b = bs->buf; |
360 |
|
|
361 |
#ifndef ARCH_IS_BIG_ENDIAN |
#ifndef ARCH_IS_BIG_ENDIAN |
362 |
BSWAP(b); |
BSWAP(b); |
363 |
#endif |
#endif |
367 |
} |
} |
368 |
} |
} |
369 |
|
|
|
|
|
|
/* pad bitstream to the next byte boundary */ |
|
|
|
|
|
static void __inline BitstreamPad(Bitstream * const bs) |
|
|
{ |
|
|
uint32_t remainder = bs->pos % 8; |
|
|
|
|
|
if (remainder) |
|
|
{ |
|
|
BitstreamForward(bs, 8 - remainder); |
|
|
} |
|
|
} |
|
|
|
|
|
|
|
370 |
/* read n bits from bitstream */ |
/* read n bits from bitstream */ |
371 |
|
|
372 |
static uint32_t __inline BitstreamGetBits(Bitstream * const bs, |
static uint32_t __inline |
373 |
|
BitstreamGetBits(Bitstream * const bs, |
374 |
const uint32_t n) |
const uint32_t n) |
375 |
{ |
{ |
376 |
uint32_t ret = BitstreamShowBits(bs, n); |
uint32_t ret = BitstreamShowBits(bs, n); |
377 |
|
|
378 |
BitstreamSkip(bs, n); |
BitstreamSkip(bs, n); |
379 |
return ret; |
return ret; |
380 |
} |
} |
382 |
|
|
383 |
/* read single bit from bitstream */ |
/* read single bit from bitstream */ |
384 |
|
|
385 |
static uint32_t __inline BitstreamGetBit(Bitstream * const bs) |
static uint32_t __inline |
386 |
|
BitstreamGetBit(Bitstream * const bs) |
387 |
{ |
{ |
388 |
return BitstreamGetBits(bs, 1); |
return BitstreamGetBits(bs, 1); |
389 |
} |
} |
391 |
|
|
392 |
/* write single bit to bitstream */ |
/* write single bit to bitstream */ |
393 |
|
|
394 |
static void __inline BitstreamPutBit(Bitstream * const bs, |
static void __inline |
395 |
|
BitstreamPutBit(Bitstream * const bs, |
396 |
const uint32_t bit) |
const uint32_t bit) |
397 |
{ |
{ |
398 |
if (bit) |
if (bit) |
404 |
|
|
405 |
/* write n bits to bitstream */ |
/* write n bits to bitstream */ |
406 |
|
|
407 |
static void __inline BitstreamPutBits(Bitstream * const bs, |
static void __inline |
408 |
|
BitstreamPutBits(Bitstream * const bs, |
409 |
const uint32_t value, |
const uint32_t value, |
410 |
const uint32_t size) |
const uint32_t size) |
411 |
{ |
{ |
429 |
} |
} |
430 |
} |
} |
431 |
|
|
432 |
|
static const int stuffing_codes[8] = |
433 |
|
{ |
434 |
|
/* nbits stuffing code */ |
435 |
|
0, /* 1 0 */ |
436 |
|
1, /* 2 01 */ |
437 |
|
3, /* 3 011 */ |
438 |
|
7, /* 4 0111 */ |
439 |
|
0xf, /* 5 01111 */ |
440 |
|
0x1f, /* 6 011111 */ |
441 |
|
0x3f, /* 7 0111111 */ |
442 |
|
0x7f, /* 8 01111111 */ |
443 |
|
}; |
444 |
|
|
445 |
|
/* pad bitstream to the next byte boundary */ |
446 |
|
|
447 |
|
static void __inline |
448 |
|
BitstreamPad(Bitstream * const bs) |
449 |
|
{ |
450 |
|
int bits = 8 - (bs->pos % 8); |
451 |
|
if (bits < 8) |
452 |
|
BitstreamPutBits(bs, stuffing_codes[bits - 1], bits); |
453 |
|
} |
454 |
|
|
455 |
|
|
456 |
|
/* |
457 |
|
* pad bitstream to the next byte boundary |
458 |
|
* alway pad: even if currently at the byte boundary |
459 |
|
*/ |
460 |
|
|
461 |
|
static void __inline |
462 |
|
BitstreamPadAlways(Bitstream * const bs) |
463 |
|
{ |
464 |
|
int bits = 8 - (bs->pos % 8); |
465 |
|
BitstreamPutBits(bs, stuffing_codes[bits - 1], bits); |
466 |
|
} |
467 |
|
|
468 |
#endif /* _BITSTREAM_H_ */ |
#endif /* _BITSTREAM_H_ */ |