Libav
gsm_parser.c
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1 /*
2  * Copyright (c) 2012 Justin Ruggles
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
28 #include "parser.h"
29 #include "gsm.h"
30 
31 typedef struct GSMParseContext {
34  int duration;
35  int remaining;
37 
39  const uint8_t **poutbuf, int *poutbuf_size,
40  const uint8_t *buf, int buf_size)
41 {
42  GSMParseContext *s = s1->priv_data;
43  ParseContext *pc = &s->pc;
44  int next;
45 
46  if (!s->block_size) {
47  switch (avctx->codec_id) {
48  case AV_CODEC_ID_GSM:
51  break;
52  case AV_CODEC_ID_GSM_MS:
53  s->block_size = avctx->block_align ? avctx->block_align
55  s->duration = GSM_FRAME_SIZE * 2;
56  break;
57  default:
58  return AVERROR(EINVAL);
59  }
60  }
61 
62  if (!s->remaining)
63  s->remaining = s->block_size;
64  if (s->remaining <= buf_size) {
65  next = s->remaining;
66  s->remaining = 0;
67  } else {
68  next = END_NOT_FOUND;
69  s->remaining -= buf_size;
70  }
71 
72  if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
73  *poutbuf = NULL;
74  *poutbuf_size = 0;
75  return buf_size;
76  }
77 
78  s1->duration = s->duration;
79 
80  *poutbuf = buf;
81  *poutbuf_size = buf_size;
82  return next;
83 }
84 
87  .priv_data_size = sizeof(GSMParseContext),
88  .parser_parse = gsm_parse,
89  .parser_close = ff_parse_close,
90 };
#define GSM_FRAME_SIZE
Definition: gsm.h:30
ParseContext pc
Definition: gsm_parser.c:32
AVCodecParser ff_gsm_parser
Definition: gsm_parser.c:85
int codec_ids[5]
Definition: avcodec.h:3822
int duration
Duration of the current frame.
Definition: avcodec.h:3798
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:1828
uint8_t
#define GSM_MS_BLOCK_SIZE
Definition: gsm.h:26
#define GSM_BLOCK_SIZE
Definition: gsm.h:25
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:217
#define AVERROR(e)
Definition: error.h:43
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:287
NULL
Definition: eval.c:55
static int gsm_parse(AVCodecParserContext *s1, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: gsm_parser.c:38
enum AVCodecID codec_id
Definition: avcodec.h:1067
main external API structure.
Definition: avcodec.h:1050
#define END_NOT_FOUND
Definition: parser.h:40
as in Berlin toast format
Definition: avcodec.h:396