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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 "thread.h"
43 
45 
46 static const uint8_t table_mb_ptype[7][2] = {
47  { 3, 5 }, // 0x01 MB_INTRA
48  { 1, 2 }, // 0x02 MB_PAT
49  { 1, 3 }, // 0x08 MB_FOR
50  { 1, 1 }, // 0x0A MB_FOR|MB_PAT
51  { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
52  { 1, 5 }, // 0x12 MB_QUANT|MB_PAT
53  { 2, 5 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
54 };
55 
56 static const uint8_t table_mb_btype[11][2] = {
57  { 3, 5 }, // 0x01 MB_INTRA
58  { 2, 3 }, // 0x04 MB_BACK
59  { 3, 3 }, // 0x06 MB_BACK|MB_PAT
60  { 2, 4 }, // 0x08 MB_FOR
61  { 3, 4 }, // 0x0A MB_FOR|MB_PAT
62  { 2, 2 }, // 0x0C MB_FOR|MB_BACK
63  { 3, 2 }, // 0x0E MB_FOR|MB_BACK|MB_PAT
64  { 1, 6 }, // 0x11 MB_QUANT|MB_INTRA
65  { 2, 6 }, // 0x16 MB_QUANT|MB_BACK|MB_PAT
66  { 3, 6 }, // 0x1A MB_QUANT|MB_FOR|MB_PAT
67  { 2, 5 }, // 0x1E MB_QUANT|MB_FOR|MB_BACK|MB_PAT
68 };
69 
70 av_cold void ff_init_2d_vlc_rl(RLTable *rl, unsigned static_size, int flags)
71 {
72  int i;
73  VLC_TYPE table[680][2] = {{0}};
74  VLC vlc = { .table = table, .table_allocated = static_size };
75  av_assert0(static_size <= FF_ARRAY_ELEMS(table));
76  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 | flags);
77 
78  for (i = 0; i < vlc.table_size; i++) {
79  int code = vlc.table[i][0];
80  int len = vlc.table[i][1];
81  int level, run;
82 
83  if (len == 0) { // illegal code
84  run = 65;
85  level = MAX_LEVEL;
86  } else if (len<0) { //more bits needed
87  run = 0;
88  level = code;
89  } else {
90  if (code == rl->n) { //esc
91  run = 65;
92  level = 0;
93  } else if (code == rl->n+1) { //eob
94  run = 0;
95  level = 127;
96  } else {
97  run = rl->table_run [code] + 1;
98  level = rl->table_level[code];
99  }
100  }
101  rl->rl_vlc[0][i].len = len;
102  rl->rl_vlc[0][i].level = level;
103  rl->rl_vlc[0][i].run = run;
104  }
105 }
106 
108 {
109 
110  s->y_dc_scale_table =
112 
113 }
114 
116 {
117  s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
118  s->last_dc[1] = s->last_dc[0];
119  s->last_dc[2] = s->last_dc[0];
120  memset(s->last_mv, 0, sizeof(s->last_mv));
121 }
122 
123 
124 /******************************************/
125 /* decoding */
126 
128 
131 
136 
138 {
139  static int done = 0;
140 
141  if (!done) {
142  done = 1;
143 
144  INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
146  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
147  INIT_VLC_STATIC(&ff_dc_chroma_vlc, DC_VLC_BITS, 12,
149  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
150  INIT_VLC_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17,
151  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
152  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
153  INIT_VLC_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36,
154  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
155  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
156  INIT_VLC_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64,
157  &ff_mpeg12_mbPatTable[0][1], 2, 1,
158  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
159 
160  INIT_VLC_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
161  &table_mb_ptype[0][1], 2, 1,
162  &table_mb_ptype[0][0], 2, 1, 64);
163  INIT_VLC_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
164  &table_mb_btype[0][1], 2, 1,
165  &table_mb_btype[0][0], 2, 1, 64);
168 
169  INIT_2D_VLC_RL(ff_rl_mpeg1, 680, 0);
170  INIT_2D_VLC_RL(ff_rl_mpeg2, 674, 0);
171  }
172 }
173 
174 /**
175  * Find the end of the current frame in the bitstream.
176  * @return the position of the first byte of the next frame, or -1
177  */
179 {
180  int i;
181  uint32_t state = pc->state;
182 
183  /* EOF considered as end of frame */
184  if (buf_size == 0)
185  return 0;
186 
187 /*
188  0 frame start -> 1/4
189  1 first_SEQEXT -> 0/2
190  2 first field start -> 3/0
191  3 second_SEQEXT -> 2/0
192  4 searching end
193 */
194 
195  for (i = 0; i < buf_size; i++) {
196  av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4);
197  if (pc->frame_start_found & 1) {
198  if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80)
199  pc->frame_start_found--;
200  else if (state == EXT_START_CODE + 2) {
201  if ((buf[i] & 3) == 3)
202  pc->frame_start_found = 0;
203  else
204  pc->frame_start_found = (pc->frame_start_found + 1) & 3;
205  }
206  state++;
207  } else {
208  i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1;
209  if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) {
210  i++;
211  pc->frame_start_found = 4;
212  }
213  if (state == SEQ_END_CODE) {
214  pc->frame_start_found = 0;
215  pc->state=-1;
216  return i+1;
217  }
218  if (pc->frame_start_found == 2 && state == SEQ_START_CODE)
219  pc->frame_start_found = 0;
220  if (pc->frame_start_found < 4 && state == EXT_START_CODE)
221  pc->frame_start_found++;
222  if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) {
223  if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) {
224  pc->frame_start_found = 0;
225  pc->state = -1;
226  return i - 3;
227  }
228  }
229  if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) {
230  ff_fetch_timestamp(s, i - 3, 1, i > 3);
231  }
232  }
233  }
234  pc->state = state;
235  return END_NOT_FOUND;
236 }
237 
238 #define MAX_INDEX (64 - 1)
239 
241  const uint16_t *quant_matrix,
242  uint8_t *const scantable, int last_dc[3],
243  int16_t *block, int index, int qscale)
244 {
245  int dc, diff, i = 0, component;
246  RLTable *rl = &ff_rl_mpeg1;
247 
248  /* DC coefficient */
249  component = index <= 3 ? 0 : index - 4 + 1;
250 
251  diff = decode_dc(gb, component);
252  if (diff >= 0xffff)
253  return AVERROR_INVALIDDATA;
254 
255  dc = last_dc[component];
256  dc += diff;
257  last_dc[component] = dc;
258 
259  block[0] = dc * quant_matrix[0];
260 
261  {
262  OPEN_READER(re, gb);
263  UPDATE_CACHE(re, gb);
264  if (((int32_t)GET_CACHE(re, gb)) <= (int32_t)0xBFFFFFFF)
265  goto end;
266 
267  /* now quantify & encode AC coefficients */
268  while (1) {
269  int level, run, j;
270 
271  GET_RL_VLC(level, run, re, gb, rl->rl_vlc[0],
272  TEX_VLC_BITS, 2, 0);
273 
274  if (level != 0) {
275  i += run;
276  if (i > MAX_INDEX)
277  break;
278 
279  j = scantable[i];
280  level = (level * qscale * quant_matrix[j]) >> 4;
281  level = (level - 1) | 1;
282  level = (level ^ SHOW_SBITS(re, gb, 1)) -
283  SHOW_SBITS(re, gb, 1);
284  SKIP_BITS(re, gb, 1);
285  } else {
286  /* escape */
287  run = SHOW_UBITS(re, gb, 6) + 1;
288  LAST_SKIP_BITS(re, gb, 6);
289  UPDATE_CACHE(re, gb);
290  level = SHOW_SBITS(re, gb, 8);
291  SKIP_BITS(re, gb, 8);
292 
293  if (level == -128) {
294  level = SHOW_UBITS(re, gb, 8) - 256;
295  SKIP_BITS(re, gb, 8);
296  } else if (level == 0) {
297  level = SHOW_UBITS(re, gb, 8);
298  SKIP_BITS(re, gb, 8);
299  }
300 
301  i += run;
302  if (i > MAX_INDEX)
303  break;
304 
305  j = scantable[i];
306  if (level < 0) {
307  level = -level;
308  level = (level * qscale * quant_matrix[j]) >> 4;
309  level = (level - 1) | 1;
310  level = -level;
311  } else {
312  level = (level * qscale * quant_matrix[j]) >> 4;
313  level = (level - 1) | 1;
314  }
315  }
316 
317  block[j] = level;
318  if (((int32_t)GET_CACHE(re, gb)) <= (int32_t)0xBFFFFFFF)
319  break;
320 
321  UPDATE_CACHE(re, gb);
322  }
323 end:
324  LAST_SKIP_BITS(re, gb, 2);
325  CLOSE_READER(re, gb);
326  }
327 
328  if (i > MAX_INDEX)
330 
331  return i;
332 }
int table_size
Definition: vlc.h:29
const char * s
Definition: avisynth_c.h:768
#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:129
const uint8_t * y_dc_scale_table
qscale -> y_dc_scale table
Definition: mpegvideo.h:188
int last_mv[2][2][2]
last MV, used for MV prediction in MPEG-1 & B-frame MPEG-4
Definition: mpegvideo.h:278
float re
Definition: fft.c:82
av_cold void ff_mpeg12_init_vlcs(void)
Definition: mpeg12.c:137
#define INIT_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size)
Definition: vlc.h:75
const unsigned char ff_mpeg12_vlc_dc_lum_bits[12]
Definition: mpeg12data.c:55
void ff_mpeg1_clean_buffers(MpegEncContext *s)
Definition: mpeg12.c:115
mpegvideo header.
const uint16_t ff_mpeg12_vlc_dc_lum_code[12]
Definition: mpeg12data.c:52
const int8_t * table_level
Definition: rl.h:44
uint8_t run
Definition: svq3.c:206
#define SLICE_MIN_START_CODE
Definition: mpegvideo.h:71
int frame_start_found
Definition: parser.h:34
RLTable.
Definition: rl.h:39
Macro definitions for various function/variable attributes.
static int16_t block[64]
Definition: dct.c:115
#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
#define INIT_2D_VLC_RL(rl, static_size, flags)
Definition: mpeg12.h:32
RLTable ff_rl_mpeg2
Definition: mpeg12data.c:174
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
Multithreading support functions.
int intra_dc_precision
Definition: mpegvideo.h:463
static const uint8_t table_mb_ptype[7][2]
Definition: mpeg12.c:46
static int flags
Definition: log.c:55
VLC ff_mv_vlc
Definition: mpeg12.c:127
#define MAX_LEVEL
Definition: rl.h:36
const uint8_t * avpriv_find_start_code(const uint8_t *p, const uint8_t *end, uint32_t *state)
#define MAX_INDEX
Definition: mpeg12.c:238
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:161
int last_dc[3]
last DC values for MPEG-1
Definition: mpegvideo.h:185
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: vlc.h:38
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:67
#define CLOSE_READER(name, gb)
Definition: get_bits.h:132
VLC ff_mb_pat_vlc
Definition: mpeg12.c:135
static int decode_dc(GetBitContext *gb, int component)
Definition: mpeg12.h:41
int8_t len
Definition: vlc.h:34
#define GET_RL_VLC(level, run, name, gb, table, bits,max_depth, need_update)
Definition: get_bits.h:517
Definition: vlc.h:26
#define SKIP_BITS(name, gb, num)
Definition: get_bits.h:176
av_cold void ff_init_2d_vlc_rl(RLTable *rl, unsigned static_size, int flags)
Definition: mpeg12.c:70
static const uint8_t table_mb_btype[11][2]
Definition: mpeg12.c:56
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:40
#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:42
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:43
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:182
#define EXT_START_CODE
Definition: cavs.h:33
static struct @271 state
RL_VLC_ELEM * rl_vlc[32]
decoding only
Definition: rl.h:48
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:194
#define FF_ARRAY_ELEMS(a)
#define MV_VLC_BITS
Definition: ituh263dec.c:54
VLC ff_dc_chroma_vlc
Definition: mpeg12.c:130
Libavcodec external API header.
Timecode helpers header.
#define MB_PTYPE_VLC_BITS
Definition: mpeg12vlc.h:39
MPEG-1/2 tables.
#define OPEN_READER(name, gb)
Definition: get_bits.h:121
av_cold int ff_rl_init(RLTable *rl, uint8_t static_store[2][2 *MAX_RUN+MAX_LEVEL+3])
Definition: rl.c:39
void * buf
Definition: avisynth_c.h:690
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:133
#define GET_CACHE(name, gb)
Definition: get_bits.h:198
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:178
#define END_NOT_FOUND
Definition: parser.h:40
av_cold void ff_mpeg12_common_init(MpegEncContext *s)
Definition: mpeg12.c:107
const uint8_t * c_dc_scale_table
qscale -> c_dc_scale table
Definition: mpegvideo.h:189
uint8_t level
Definition: svq3.c:207
#define DC_VLC_BITS
Definition: intrax8.c:37
MpegEncContext.
Definition: mpegvideo.h:81
uint8_t run
Definition: vlc.h:35
#define MAX_RUN
Definition: rl.h:35
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:195
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:240
common internal api header.
#define TEX_VLC_BITS
Definition: dv.h:96
uint8_t ff_mpeg12_static_rl_table_store[2][2][2 *MAX_RUN+MAX_LEVEL+3]
Definition: mpeg12.c:44
#define INIT_VLC_USE_NEW_STATIC
Definition: vlc.h:55
VLC ff_mbincr_vlc
Definition: mpeg12.c:132
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)
int len
#define SEQ_START_CODE
Definition: mpegvideo.h:68
const uint8_t ff_mpeg12_mbAddrIncrTable[36][2]
Definition: mpeg12data.c:182
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
int16_t level
Definition: vlc.h:33
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:70
#define VLC_TYPE
Definition: vlc.h:24
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:174
VLC ff_mb_btype_vlc
Definition: mpeg12.c:134