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mpeg12.c
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1 /*
2  * MPEG-1/2 decoder
3  * Copyright (c) 2000, 2001 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * MPEG-1/2 decoder
26  */
27 
28 #define UNCHECKED_BITSTREAM_READER 1
29 
30 #include "libavutil/attributes.h"
31 #include "libavutil/avassert.h"
32 #include "libavutil/timecode.h"
33 
34 #include "internal.h"
35 #include "avcodec.h"
36 #include "mpegvideo.h"
37 #include "error_resilience.h"
38 #include "mpeg12.h"
39 #include "mpeg12data.h"
40 #include "mpegvideodata.h"
41 #include "bytestream.h"
42 #include "vdpau_internal.h"
43 #include "thread.h"
44 
46 
47 static const uint8_t table_mb_ptype[7][2] = {
48  { 3, 5 }, // 0x01 MB_INTRA
49  { 1, 2 }, // 0x02 MB_PAT
50  { 1, 3 }, // 0x08 MB_FOR
51  { 1, 1 }, // 0x0A MB_FOR|MB_PAT
52  { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
53  { 1, 5 }, // 0x12 MB_QUANT|MB_PAT
54  { 2, 5 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
55 };
56 
57 static const uint8_t table_mb_btype[11][2] = {
58  { 3, 5 }, // 0x01 MB_INTRA
59  { 2, 3 }, // 0x04 MB_BACK
60  { 3, 3 }, // 0x06 MB_BACK|MB_PAT
61  { 2, 4 }, // 0x08 MB_FOR
62  { 3, 4 }, // 0x0A MB_FOR|MB_PAT
63  { 2, 2 }, // 0x0C MB_FOR|MB_BACK
64  { 3, 2 }, // 0x0E MB_FOR|MB_BACK|MB_PAT
65  { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
66  { 2, 6 }, // 0x16 MB_QUANT|MB_BACK|MB_PAT
67  { 3, 6 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
68  { 2, 5 }, // 0x1E MB_QUANT|MB_FOR|MB_BACK|MB_PAT
69 };
70 
71 #define INIT_2D_VLC_RL(rl, static_size)\
72 {\
73  static RL_VLC_ELEM rl_vlc_table[static_size];\
74  rl.rl_vlc[0] = rl_vlc_table;\
75  init_2d_vlc_rl(&rl, static_size);\
76 }
77 
78 static av_cold void init_2d_vlc_rl(RLTable *rl, unsigned static_size)
79 {
80  int i;
81  VLC_TYPE table[680][2] = {{0}};
82  VLC vlc = { .table = table, .table_allocated = static_size };
83  av_assert0(static_size <= FF_ARRAY_ELEMS(table));
84  init_vlc(&vlc, TEX_VLC_BITS, rl->n + 2, &rl->table_vlc[0][1], 4, 2, &rl->table_vlc[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
85 
86  for (i = 0; i < vlc.table_size; i++) {
87  int code = vlc.table[i][0];
88  int len = vlc.table[i][1];
89  int level, run;
90 
91  if (len == 0) { // illegal code
92  run = 65;
93  level = MAX_LEVEL;
94  } else if (len<0) { //more bits needed
95  run = 0;
96  level = code;
97  } else {
98  if (code == rl->n) { //esc
99  run = 65;
100  level = 0;
101  } else if (code == rl->n+1) { //eob
102  run = 0;
103  level = 127;
104  } else {
105  run = rl->table_run [code] + 1;
106  level = rl->table_level[code];
107  }
108  }
109  rl->rl_vlc[0][i].len = len;
110  rl->rl_vlc[0][i].level = level;
111  rl->rl_vlc[0][i].run = run;
112  }
113 }
114 
116 {
117 
118  s->y_dc_scale_table =
120 
121 }
122 
124 {
125  s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
126  s->last_dc[1] = s->last_dc[0];
127  s->last_dc[2] = s->last_dc[0];
128  memset(s->last_mv, 0, sizeof(s->last_mv));
129 }
130 
131 
132 /******************************************/
133 /* decoding */
134 
136 
139 
144 
146 {
147  static int done = 0;
148 
149  if (!done) {
150  done = 1;
151 
152  INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
154  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
155  INIT_VLC_STATIC(&ff_dc_chroma_vlc, DC_VLC_BITS, 12,
157  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
158  INIT_VLC_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17,
159  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
160  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
161  INIT_VLC_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
162  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
163  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
164  INIT_VLC_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
165  &ff_mpeg12_mbPatTable[0][1], 2, 1,
166  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
167 
168  INIT_VLC_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
169  &table_mb_ptype[0][1], 2, 1,
170  &table_mb_ptype[0][0], 2, 1, 64);
171  INIT_VLC_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
172  &table_mb_btype[0][1], 2, 1,
173  &table_mb_btype[0][0], 2, 1, 64);
176 
179  }
180 }
181 
182 /**
183  * Find the end of the current frame in the bitstream.
184  * @return the position of the first byte of the next frame, or -1
185  */
187 {
188  int i;
189  uint32_t state = pc->state;
190 
191  /* EOF considered as end of frame */
192  if (buf_size == 0)
193  return 0;
194 
195 /*
196  0 frame start -> 1/4
197  1 first_SEQEXT -> 0/2
198  2 first field start -> 3/0
199  3 second_SEQEXT -> 2/0
200  4 searching end
201 */
202 
203  for (i = 0; i < buf_size; i++) {
204  av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
205  if (pc->frame_start_found & 1) {
206  if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
207  pc->frame_start_found--;
208  else if (state == EXT_START_CODE + 2) {
209  if ((buf[i] & 3) == 3)
210  pc->frame_start_found = 0;
211  else
212  pc->frame_start_found = (pc->frame_start_found + 1) & 3;
213  }
214  state++;
215  } else {
216  i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
217  if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
218  i++;
219  pc->frame_start_found = 4;
220  }
221  if (state == SEQ_END_CODE) {
222  pc->frame_start_found = 0;
223  pc->state=-1;
224  return i+1;
225  }
226  if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
227  pc->frame_start_found = 0;
228  if (pc->frame_start_found < 4 && state == EXT_START_CODE)
229  pc->frame_start_found++;
230  if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
231  if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
232  pc->frame_start_found = 0;
233  pc->state = -1;
234  return i - 3;
235  }
236  }
237  if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
238  ff_fetch_timestamp(s, i - 3, 1, i > 3);
239  }
240  }
241  }
242  pc->state = state;
243  return END_NOT_FOUND;
244 }
245 
246 #define MAX_INDEX (64 - 1)
247 
249  const uint16_t *quant_matrix,
250  uint8_t *const scantable, int last_dc[3],
251  int16_t *block, int index, int qscale)
252 {
253  int dc, diff, i = 0, component;
254  RLTable *rl = &ff_rl_mpeg1;
255 
256  /* DC coefficient */
257  component = index <= 3 ? 0 : index - 4 + 1;
258 
259  diff = decode_dc(gb, component);
260  if (diff >= 0xffff)
261  return AVERROR_INVALIDDATA;
262 
263  dc = last_dc[component];
264  dc += diff;
265  last_dc[component] = dc;
266 
267  block[0] = dc * quant_matrix[0];
268 
269  {
270  OPEN_READER(re, gb);
271  UPDATE_CACHE(re, gb);
272  if (((int32_t)GET_CACHE(re, gb)) <= (int32_t)0xBFFFFFFF)
273  goto end;
274 
275  /* now quantify & encode AC coefficients */
276  while (1) {
277  int level, run, j;
278 
279  GET_RL_VLC(level, run, re, gb, rl->rl_vlc[0],
280  TEX_VLC_BITS, 2, 0);
281 
282  if (level != 0) {
283  i += run;
284  if (i > MAX_INDEX)
285  break;
286 
287  j = scantable[i];
288  level = (level * qscale * quant_matrix[j]) >> 4;
289  level = (level - 1) | 1;
290  level = (level ^ SHOW_SBITS(re, gb, 1)) -
291  SHOW_SBITS(re, gb, 1);
292  SKIP_BITS(re, gb, 1);
293  } else {
294  /* escape */
295  run = SHOW_UBITS(re, gb, 6) + 1;
296  LAST_SKIP_BITS(re, gb, 6);
297  UPDATE_CACHE(re, gb);
298  level = SHOW_SBITS(re, gb, 8);
299  SKIP_BITS(re, gb, 8);
300 
301  if (level == -128) {
302  level = SHOW_UBITS(re, gb, 8) - 256;
303  SKIP_BITS(re, gb, 8);
304  } else if (level == 0) {
305  level = SHOW_UBITS(re, gb, 8);
306  SKIP_BITS(re, gb, 8);
307  }
308 
309  i += run;
310  if (i > MAX_INDEX)
311  break;
312 
313  j = scantable[i];
314  if (level < 0) {
315  level = -level;
316  level = (level * qscale * quant_matrix[j]) >> 4;
317  level = (level - 1) | 1;
318  level = -level;
319  } else {
320  level = (level * qscale * quant_matrix[j]) >> 4;
321  level = (level - 1) | 1;
322  }
323  }
324 
325  block[j] = level;
326  if (((int32_t)GET_CACHE(re, gb)) <= (int32_t)0xBFFFFFFF)
327  break;
328 
329  UPDATE_CACHE(re, gb);
330  }
331 end:
332  LAST_SKIP_BITS(re, gb, 2);
333  CLOSE_READER(re, gb);
334  }
335 
336  if (i > MAX_INDEX)
338 
339  return i;
340 }
int table_size
Definition: get_bits.h:66
const char * s
Definition: avisynth_c.h:631
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define SLICE_MAX_START_CODE
Definition: cavs.h:32
VLC ff_dc_lum_vlc
Definition: mpeg12.c:137
#define GET_RL_VLC
Definition: get_bits.h:708
const uint8_t * y_dc_scale_table
qscale -> y_dc_scale table
Definition: mpegvideo.h:185
int last_mv[2][2][2]
last MV, used for MV prediction in MPEG1 & B-frame MPEG4
Definition: mpegvideo.h:278
av_cold void ff_mpeg12_init_vlcs(void)
Definition: mpeg12.c:145
const unsigned char ff_mpeg12_vlc_dc_lum_bits[12]
Definition: mpeg12data.c:55
void ff_mpeg1_clean_buffers(MpegEncContext *s)
Definition: mpeg12.c:123
#define VLC_TYPE
Definition: get_bits.h:61
mpegvideo header.
const uint16_t ff_mpeg12_vlc_dc_lum_code[12]
Definition: mpeg12data.c:52
const int8_t * table_level
Definition: rl.h:43
uint8_t run
Definition: svq3.c:192
#define SLICE_MIN_START_CODE
Definition: mpegvideo.h:70
static struct @224 state
int frame_start_found
Definition: parser.h:34
RLTable.
Definition: rl.h:38
Macro definitions for various function/variable attributes.
#define INIT_2D_VLC_RL(rl, static_size)
Definition: mpeg12.c:71
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
#define MBINCR_VLC_BITS
Definition: mpeg12vlc.h:37
uint8_t
#define av_cold
Definition: attributes.h:82
RLTable ff_rl_mpeg2
Definition: mpeg12data.c:174
#define INIT_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size)
Definition: get_bits.h:484
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
Multithreading support functions.
int intra_dc_precision
Definition: mpegvideo.h:460
static const uint8_t table_mb_ptype[7][2]
Definition: mpeg12.c:47
VLC ff_mv_vlc
Definition: mpeg12.c:135
#define MAX_LEVEL
Definition: rl.h:35
const uint8_t * avpriv_find_start_code(const uint8_t *p, const uint8_t *end, uint32_t *state)
#define MAX_INDEX
Definition: mpeg12.c:246
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:173
int last_dc[3]
last DC values for MPEG1
Definition: mpegvideo.h:182
static const struct endianess table[]
const uint16_t ff_mpeg12_vlc_dc_chroma_code[12]
Definition: mpeg12data.c:59
simple assert() macros that are a bit more flexible than ISO C assert().
#define SEQ_END_CODE
Definition: mpegvideo.h:66
#define CLOSE_READER(name, gb)
Definition: get_bits.h:144
VLC ff_mb_pat_vlc
Definition: mpeg12.c:143
static int decode_dc(GetBitContext *gb, int component)
Definition: mpeg12.h:32
int8_t len
Definition: get_bits.h:71
Definition: get_bits.h:63
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:188
static const uint8_t table_mb_btype[11][2]
Definition: mpeg12.c:57
const uint8_t *const ff_mpeg2_dc_scale_table[4]
Definition: mpegvideodata.c:82
int n
number of entries of table_vlc minus 1
Definition: rl.h:39
#define MB_PAT_VLC_BITS
Definition: mpeg12vlc.h:38
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
Definition: avassert.h:53
const uint16_t(* table_vlc)[2]
Definition: rl.h:41
const unsigned char ff_mpeg12_vlc_dc_chroma_bits[12]
Definition: mpeg12data.c:62
RLTable ff_rl_mpeg1
Definition: mpeg12data.c:166
#define MB_BTYPE_VLC_BITS
Definition: mpeg12vlc.h:40
int32_t
const int8_t * table_run
Definition: rl.h:42
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:194
#define EXT_START_CODE
Definition: cavs.h:33
#define INIT_VLC_USE_NEW_STATIC
Definition: get_bits.h:482
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:47
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:206
#define FF_ARRAY_ELEMS(a)
static av_cold void init_2d_vlc_rl(RLTable *rl, unsigned static_size)
Definition: mpeg12.c:78
#define MV_VLC_BITS
Definition: ituh263dec.c:54
VLC ff_dc_chroma_vlc
Definition: mpeg12.c:138
Libavcodec external API header.
Timecode helpers header.
#define MB_PTYPE_VLC_BITS
Definition: mpeg12vlc.h:39
MPEG1/2 tables.
#define OPEN_READER(name, gb)
Definition: get_bits.h:133
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: get_bits.h:465
av_cold int ff_rl_init(RLTable *rl, uint8_t static_store[2][2 *MAX_RUN+MAX_LEVEL+3])
Definition: rl.c:37
void * buf
Definition: avisynth_c.h:553
uint32_t state
contains the last few bytes in MSB order
Definition: parser.h:33
int index
Definition: gxfenc.c:89
VLC ff_mb_ptype_vlc
Definition: mpeg12.c:141
#define GET_CACHE(name, gb)
Definition: get_bits.h:210
int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
Find the end of the current frame in the bitstream.
Definition: mpeg12.c:186
#define END_NOT_FOUND
Definition: parser.h:40
av_cold void ff_mpeg12_common_init(MpegEncContext *s)
Definition: mpeg12.c:115
const uint8_t * c_dc_scale_table
qscale -> c_dc_scale table
Definition: mpegvideo.h:186
uint8_t level
Definition: svq3.c:193
#define DC_VLC_BITS
Definition: intrax8.c:37
MpegEncContext.
Definition: mpegvideo.h:78
uint8_t run
Definition: get_bits.h:72
#define MAX_RUN
Definition: rl.h:34
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:207
int ff_mpeg1_decode_block_intra(GetBitContext *gb, const uint16_t *quant_matrix, uint8_t *const scantable, int last_dc[3], int16_t *block, int index, int qscale)
Definition: mpeg12.c:248
common internal api header.
#define TEX_VLC_BITS
Definition: dv.h:93
uint8_t ff_mpeg12_static_rl_table_store[2][2][2 *MAX_RUN+MAX_LEVEL+3]
Definition: mpeg12.c:45
VLC ff_mbincr_vlc
Definition: mpeg12.c:140
const uint8_t ff_mpeg12_mbPatTable[64][2]
Definition: mpeg12data.c:221
static av_always_inline int diff(const uint32_t a, const uint32_t b)
float re
Definition: fft-test.c:73
int len
#define SEQ_START_CODE
Definition: mpegvideo.h:67
const uint8_t ff_mpeg12_mbAddrIncrTable[36][2]
Definition: mpeg12data.c:182
VLC_TYPE(* table)[2]
code, bits
Definition: get_bits.h:65
int16_t level
Definition: get_bits.h:70
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31))))#defineSET_CONV_FUNC_GROUP(ofmt, ifmt) staticvoidset_generic_function(AudioConvert *ac){}voidff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, intsample_rate, intapply_map){AudioConvert *ac;intin_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) returnNULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt)>2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);returnNULL;}returnac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}elseif(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;elseac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);returnac;}intff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){intuse_generic=1;intlen=in->nb_samples;intp;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%dsamples-audio_convert:%sto%s(dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));returnff_convert_dither(ac-> dc
const uint8_t ff_mpeg12_mbMotionVectorTable[17][2]
Definition: mpeg12data.c:288
#define PICTURE_START_CODE
Definition: mpegvideo.h:69
void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
Fetch timestamps for a specific byte within the current access unit.
Definition: parser.c:105
static int16_t block[64]
Definition: dct-test.c:112
VLC ff_mb_btype_vlc
Definition: mpeg12.c:142