parser.c
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1 /*
2  * Audio and Video frame extraction
3  * Copyright (c) 2003 Fabrice Bellard
4  * Copyright (c) 2003 Michael Niedermayer
5  *
6  * This file is part of Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "parser.h"
24 
26 
28  if(p) return p->next;
29  else return av_first_parser;
30 }
31 
33 {
34  parser->next = av_first_parser;
35  av_first_parser = parser;
36 }
37 
39 {
41  AVCodecParser *parser;
42  int ret;
43 
44  if(codec_id == CODEC_ID_NONE)
45  return NULL;
46 
47  for(parser = av_first_parser; parser != NULL; parser = parser->next) {
48  if (parser->codec_ids[0] == codec_id ||
49  parser->codec_ids[1] == codec_id ||
50  parser->codec_ids[2] == codec_id ||
51  parser->codec_ids[3] == codec_id ||
52  parser->codec_ids[4] == codec_id)
53  goto found;
54  }
55  return NULL;
56  found:
57  s = av_mallocz(sizeof(AVCodecParserContext));
58  if (!s)
59  return NULL;
60  s->parser = parser;
61  if (parser->priv_data_size) {
62  s->priv_data = av_mallocz(parser->priv_data_size);
63  if (!s->priv_data) {
64  av_free(s);
65  return NULL;
66  }
67  }
68  if (parser->parser_init) {
69  ret = parser->parser_init(s);
70  if (ret != 0) {
71  av_free(s->priv_data);
72  av_free(s);
73  return NULL;
74  }
75  }
76  s->fetch_timestamp=1;
78  s->key_frame = -1;
79  s->convergence_duration = 0;
80  s->dts_sync_point = INT_MIN;
81  s->dts_ref_dts_delta = INT_MIN;
82  s->pts_dts_delta = INT_MIN;
83  return s;
84 }
85 
86 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){
87  int i;
88 
89  s->dts= s->pts= AV_NOPTS_VALUE;
90  s->pos= -1;
91  s->offset= 0;
92  for(i = 0; i < AV_PARSER_PTS_NB; i++) {
93  if ( s->cur_offset + off >= s->cur_frame_offset[i]
94  && (s->frame_offset < s->cur_frame_offset[i] ||
95  (!s->frame_offset && !s->next_frame_offset)) // first field/frame
96  //check is disabled because mpeg-ts doesnt send complete PES packets
97  && /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
98  s->dts= s->cur_frame_dts[i];
99  s->pts= s->cur_frame_pts[i];
100  s->pos= s->cur_frame_pos[i];
101  s->offset = s->next_frame_offset - s->cur_frame_offset[i];
102  if(remove)
104  if(s->cur_offset + off < s->cur_frame_end[i])
105  break;
106  }
107  }
108 }
109 
111  AVCodecContext *avctx,
112  uint8_t **poutbuf, int *poutbuf_size,
113  const uint8_t *buf, int buf_size,
114  int64_t pts, int64_t dts,
115  int64_t pos)
116 {
117  int index, i;
118  uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
119 
120  if(!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
121  s->next_frame_offset =
122  s->cur_offset = pos;
124  }
125 
126  if (buf_size == 0) {
127  /* padding is always necessary even if EOF, so we add it here */
128  memset(dummy_buf, 0, sizeof(dummy_buf));
129  buf = dummy_buf;
130  } else if (s->cur_offset + buf_size !=
131  s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
132  /* add a new packet descriptor */
133  i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
134  s->cur_frame_start_index = i;
135  s->cur_frame_offset[i] = s->cur_offset;
136  s->cur_frame_end[i] = s->cur_offset + buf_size;
137  s->cur_frame_pts[i] = pts;
138  s->cur_frame_dts[i] = dts;
139  s->cur_frame_pos[i] = pos;
140  }
141 
142  if (s->fetch_timestamp){
143  s->fetch_timestamp=0;
144  s->last_pts = s->pts;
145  s->last_dts = s->dts;
146  s->last_pos = s->pos;
147  ff_fetch_timestamp(s, 0, 0);
148  }
149 
150  /* WARNING: the returned index can be negative */
151  index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
152 //av_log(NULL, AV_LOG_DEBUG, "parser: in:%"PRId64", %"PRId64", out:%"PRId64", %"PRId64", in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id);
153  /* update the file pointer */
154  if (*poutbuf_size) {
155  /* fill the data for the current frame */
157 
158  /* offset of the next frame */
160  s->fetch_timestamp=1;
161  }
162  if (index < 0)
163  index = 0;
164  s->cur_offset += index;
165  return index;
166 }
167 
174  AVCodecContext *avctx,
175  uint8_t **poutbuf, int *poutbuf_size,
176  const uint8_t *buf, int buf_size, int keyframe){
177 
178  if(s && s->parser->split){
179  if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
180  int i= s->parser->split(avctx, buf, buf_size);
181  buf += i;
182  buf_size -= i;
183  }
184  }
185 
186  /* cast to avoid warning about discarding qualifiers */
187  *poutbuf= (uint8_t *) buf;
188  *poutbuf_size= buf_size;
189  if(avctx->extradata){
190  if( (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
191  /*||(s->pict_type != AV_PICTURE_TYPE_I && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
192  /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
193  int size= buf_size + avctx->extradata_size;
194  *poutbuf_size= size;
195  *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
196 
197  memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
198  memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
199  return 1;
200  }
201  }
202 
203  return 0;
204 }
205 
207 {
208  if(s){
209  if (s->parser->parser_close)
210  s->parser->parser_close(s);
211  av_free(s->priv_data);
212  av_free(s);
213  }
214 }
215 
216 /*****************************************************/
217 
222 int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
223 {
224  if(pc->overread){
225  av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
226  pc->overread, pc->state, next, pc->index, pc->overread_index);
227  av_dlog(NULL, "%X %X %X %X\n", (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
228  }
229 
230  /* Copy overread bytes from last frame into buffer. */
231  for(; pc->overread>0; pc->overread--){
232  pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
233  }
234 
235  /* flush remaining if EOF */
236  if(!*buf_size && next == END_NOT_FOUND){
237  next= 0;
238  }
239 
240  pc->last_index= pc->index;
241 
242  /* copy into buffer end return */
243  if(next == END_NOT_FOUND){
244  void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
245 
246  if(!new_buffer)
247  return AVERROR(ENOMEM);
248  pc->buffer = new_buffer;
249  memcpy(&pc->buffer[pc->index], *buf, *buf_size);
250  pc->index += *buf_size;
251  return -1;
252  }
253 
254  *buf_size=
255  pc->overread_index= pc->index + next;
256 
257  /* append to buffer */
258  if(pc->index){
259  void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
260 
261  if(!new_buffer)
262  return AVERROR(ENOMEM);
263  pc->buffer = new_buffer;
264  if (next > -FF_INPUT_BUFFER_PADDING_SIZE)
265  memcpy(&pc->buffer[pc->index], *buf,
267  pc->index = 0;
268  *buf= pc->buffer;
269  }
270 
271  /* store overread bytes */
272  for(;next < 0; next++){
273  pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
274  pc->state64 = (pc->state64<<8) | pc->buffer[pc->last_index + next];
275  pc->overread++;
276  }
277 
278  if(pc->overread){
279  av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
280  pc->overread, pc->state, next, pc->index, pc->overread_index);
281  av_dlog(NULL, "%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
282  }
283 
284  return 0;
285 }
286 
288 {
289  ParseContext *pc = s->priv_data;
290 
291  av_freep(&pc->buffer);
292 }
293 
295 {
296  ParseContext1 *pc1 = s->priv_data;
297 
298  av_free(pc1->pc.buffer);
299  av_free(pc1->enc);
300 }
301 
302 /*************************/
303 
305  const uint8_t *buf, int buf_size)
306 {
307  int i;
308  uint32_t state= -1;
309 
310  for(i=0; i<buf_size; i++){
311  state= (state<<8) | buf[i];
312  if(state == 0x1B3 || state == 0x1B6)
313  return i-3;
314  }
315  return 0;
316 }
int(* parser_init)(AVCodecParserContext *s)
Definition: avcodec.h:4544
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:154
#define CODEC_FLAG2_LOCAL_HEADER
Place global headers at every keyframe instead of in extradata.
Definition: avcodec.h:660
int size
int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx, uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size, int keyframe)
Definition: parser.c:173
int64_t next_frame_offset
Definition: avcodec.h:4419
int codec_ids[5]
Definition: avcodec.h:4542
AVCodecParser * av_parser_next(AVCodecParser *p)
Definition: parser.c:27
int64_t cur_frame_pos[AV_PARSER_PTS_NB]
Position of the packet in file.
Definition: avcodec.h:4528
int dts_ref_dts_delta
Offset of the current timestamp against last timestamp sync point in units of AVCodecContext.time_base.
Definition: avcodec.h:4507
int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
Definition: parser.c:304
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:147
void ff_parse1_close(AVCodecParserContext *s)
Definition: parser.c:294
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1387
void av_parser_close(AVCodecParserContext *s)
Definition: parser.c:206
struct AVCodecParser * next
Definition: avcodec.h:4551
int(* parser_parse)(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: avcodec.h:4545
void av_register_codec_parser(AVCodecParser *parser)
Definition: parser.c:32
void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove)
Fetch timestamps for a specific byte within the current access unit.
Definition: parser.c:86
enum CodecID codec_id
Definition: mov_chan.c:417
unsigned int buffer_size
Definition: parser.h:32
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:137
int64_t pos
Byte position of currently parsed frame in stream.
Definition: avcodec.h:4533
int priv_data_size
Definition: avcodec.h:4543
struct AVCodecParser * parser
Definition: avcodec.h:4415
int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
Combine the (truncated) bitstream to a complete frame.
Definition: parser.c:222
#define AVERROR(e)
Definition: error.h:43
int flags
CODEC_FLAG_*.
Definition: avcodec.h:1355
int overread_index
the index into ParseContext.buffer of the overread bytes
Definition: parser.h:36
int64_t cur_frame_dts[AV_PARSER_PTS_NB]
Definition: avcodec.h:4444
int off
Definition: dsputil_bfin.c:28
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:287
int overread
the number of bytes which where irreversibly read from the next frame
Definition: parser.h:35
int last_index
Definition: parser.h:31
void(* parser_close)(AVCodecParserContext *s)
Definition: avcodec.h:4549
int64_t offset
byte offset from starting packet start
Definition: avcodec.h:4452
int64_t convergence_duration
Time difference in stream time base units from the pts of this packet to the point at which the outpu...
Definition: avcodec.h:4480
int64_t cur_frame_end[AV_PARSER_PTS_NB]
Definition: avcodec.h:4453
int64_t cur_frame_pts[AV_PARSER_PTS_NB]
Definition: avcodec.h:4443
#define av_dlog(pctx,...)
av_dlog macros Useful to print debug messages that shouldn't get compiled in normally.
Definition: log.h:158
int64_t last_pos
Previous frame byte position.
Definition: avcodec.h:4538
int pts_dts_delta
Presentation delay of current frame in units of AVCodecContext.time_base.
Definition: avcodec.h:4521
NULL
Definition: eval.c:50
uint8_t * buffer
Definition: parser.h:29
main external API structure.
Definition: avcodec.h:1329
#define PARSER_FLAG_FETCHED_OFFSET
Set if the parser has a valid file offset.
Definition: avcodec.h:4450
#define INT64_MAX
Definition: internal.h:80
uint32_t state
contains the last few bytes in MSB order
Definition: parser.h:33
int extradata_size
Definition: avcodec.h:1388
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:64
#define CODEC_FLAG_GLOBAL_HEADER
Place global headers in extradata instead of every keyframe.
Definition: avcodec.h:648
int index
Definition: gxfenc.c:73
uint64_t state64
contains the last 8 bytes in MSB order
Definition: parser.h:37
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:497
static AVCodecParser * av_first_parser
Definition: parser.c:25
#define END_NOT_FOUND
Definition: parser.h:55
#define AV_PARSER_PTS_NB
Definition: avcodec.h:4440
static uint32_t state
Definition: trasher.c:25
ParseContext pc
Definition: parser.h:43
int(* split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
Definition: avcodec.h:4550
int index
Definition: parser.h:30
int64_t cur_frame_offset[AV_PARSER_PTS_NB]
Definition: avcodec.h:4442
AVCodecParserContext * av_parser_init(int codec_id)
Definition: parser.c:38
int64_t frame_offset
Definition: avcodec.h:4416
void * av_fast_realloc(void *ptr, unsigned int *size, size_t min_size)
Reallocate the given block if it is not large enough, otherwise do nothing.
Definition: utils.c:55
int flags2
CODEC_FLAG2_*.
Definition: avcodec.h:2357
struct MpegEncContext * enc
Definition: parser.h:51
int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx, uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size, int64_t pts, int64_t dts, int64_t pos)
Parse a packet.
Definition: parser.c:110
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:4461
int dts_sync_point
Synchronization point for start of timestamp generation.
Definition: avcodec.h:4492
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:271