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gsm_parser.c
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1 /*
2  * Copyright (c) 2012 Justin Ruggles
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  * GSM audio parser
24  *
25  * Splits packets into individual blocks.
26  */
27 
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 {
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  *poutbuf = buf;
59  *poutbuf_size = buf_size;
60  av_log(avctx, AV_LOG_ERROR, "Invalid codec_id\n");
61  return buf_size;
62  }
63  }
64 
65  if (!s->remaining)
66  s->remaining = s->block_size;
67  if (s->remaining <= buf_size) {
68  next = s->remaining;
69  s->remaining = 0;
70  } else {
71  next = END_NOT_FOUND;
72  s->remaining -= buf_size;
73  }
74 
75  if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
76  *poutbuf = NULL;
77  *poutbuf_size = 0;
78  return buf_size;
79  }
80 
81  s1->duration = s->duration;
82 
83  *poutbuf = buf;
84  *poutbuf_size = buf_size;
85  return next;
86 }
87 
90  .priv_data_size = sizeof(GSMParseContext),
91  .parser_parse = gsm_parse,
92  .parser_close = ff_parse_close,
93 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
#define GSM_FRAME_SIZE
Definition: gsm.h:30
ParseContext pc
Definition: gsm_parser.c:32
AVCodecParser ff_gsm_parser
Definition: gsm_parser.c:88
int codec_ids[5]
Definition: avcodec.h:4426
int duration
Duration of the current frame.
Definition: avcodec.h:4380
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2022
uint8_t
#define GSM_MS_BLOCK_SIZE
Definition: gsm.h:26
#define GSM_BLOCK_SIZE
Definition: gsm.h:25
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
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:231
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:307
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:1258
main external API structure.
Definition: avcodec.h:1241
void * buf
Definition: avisynth_c.h:553
#define s1
Definition: regdef.h:38
#define END_NOT_FOUND
Definition: parser.h:40
as in Berlin toast format
Definition: avcodec.h:438