FFmpeg
g729_parser.c
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1 /*
2  * Copyright (c) 2015 Ganesh Ajjanagadde
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * G.729 audio parser
24  *
25  * Splits packets into individual blocks.
26  */
27 
28 #include "libavutil/avassert.h"
29 #include "parser.h"
30 #include "g729.h"
31 
32 typedef struct G729ParseContext {
35  int duration;
36  int remaining;
38 
40  const uint8_t **poutbuf, int *poutbuf_size,
41  const uint8_t *buf, int buf_size)
42 {
44  ParseContext *pc = &s->pc;
45  int next;
46 
47  if (!s->block_size) {
49  /* FIXME: replace this heuristic block_size with more precise estimate */
51  s->block_size *= avctx->channels;
52  s->duration = avctx->frame_size;
53  }
54 
55  if (!s->remaining)
56  s->remaining = s->block_size;
57  if (s->remaining <= buf_size) {
58  next = s->remaining;
59  s->remaining = 0;
60  } else {
61  next = END_NOT_FOUND;
62  s->remaining -= buf_size;
63  }
64 
65  if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
66  *poutbuf = NULL;
67  *poutbuf_size = 0;
68  return buf_size;
69  }
70 
71  s1->duration = s->duration;
72 
73  *poutbuf = buf;
74  *poutbuf_size = buf_size;
75  return next;
76 }
77 
80  .priv_data_size = sizeof(G729ParseContext),
81  .parser_parse = g729_parse,
82  .parser_close = ff_parse_close,
83 };
#define NULL
Definition: coverity.c:32
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1615
int codec_ids[5]
Definition: avcodec.h:5276
int duration
Duration of the current frame.
Definition: avcodec.h:5230
uint8_t
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:234
simple assert() macros that are a bit more flexible than ISO C assert().
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:315
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
Definition: avassert.h:53
#define s(width, name)
Definition: cbs_vp9.c:257
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:2245
enum AVCodecID codec_id
Definition: avcodec.h:1575
main external API structure.
Definition: avcodec.h:1565
void * buf
Definition: avisynth_c.h:766
#define G729D_6K4_BLOCK_SIZE
Definition: g729.h:31
#define s1
Definition: regdef.h:38
#define END_NOT_FOUND
Definition: parser.h:40
#define G729_8K_BLOCK_SIZE
Definition: g729.h:30
int channels
number of audio channels
Definition: avcodec.h:2226
static int g729_parse(AVCodecParserContext *s1, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: g729_parser.c:39
AVCodecParser ff_g729_parser
Definition: g729_parser.c:78
ParseContext pc
Definition: g729_parser.c:33