FFmpeg
ftr_parser.c
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1 /*
2  * FTR parser
3  * Copyright (c) 2022 Paul B Mahol
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * FTR parser
25  */
26 
27 #include "parser.h"
28 #include "adts_header.h"
29 #include "adts_parser.h"
30 #include "mpeg4audio.h"
31 
32 typedef struct FTRParseContext {
34  int skip;
35  int split;
38 
40  const uint8_t **poutbuf, int *poutbuf_size,
41  const uint8_t *buf, int buf_size)
42 {
43  uint8_t tmp[8 + AV_INPUT_BUFFER_PADDING_SIZE];
44  FTRParseContext *ftr = s->priv_data;
45  uint64_t state = ftr->pc.state64;
46  int next = END_NOT_FOUND;
48  int size;
49 
50  *poutbuf_size = 0;
51  *poutbuf = NULL;
52 
53  if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
54  next = buf_size;
55  } else {
56  for (int i = 0; i < buf_size; i++) {
57  if (ftr->skip > 0) {
58  ftr->skip--;
59  if (ftr->skip == 0 && ftr->split) {
60  ftr->split = 0;
61  next = i;
62  s->duration = 1024;
63  s->key_frame = 1;
64  break;
65  } else if (ftr->skip > 0) {
66  continue;
67  }
68  }
69 
70  state = (state << 8) | buf[i];
71  AV_WB64(tmp, state);
73 
74  if (size > 0) {
75  ftr->skip = size - 6;
77  if (ftr->frame_index >= avctx->ch_layout.nb_channels) {
78  ftr->frame_index = 0;
79  ftr->split = 1;
80  }
81  }
82  }
83 
84  ftr->pc.state64 = state;
85 
86  if (ff_combine_frame(&ftr->pc, next, &buf, &buf_size) < 0) {
87  *poutbuf = NULL;
88  *poutbuf_size = 0;
89  return buf_size;
90  }
91  }
92 
93  *poutbuf = buf;
94  *poutbuf_size = buf_size;
95 
96  return next;
97 }
98 
100  .codec_ids = { AV_CODEC_ID_FTR },
101  .priv_data_size = sizeof(FTRParseContext),
102  .parser_parse = ftr_parse,
103  .parser_close = ff_parse_close,
104 };
AV_AAC_ADTS_HEADER_SIZE
#define AV_AAC_ADTS_HEADER_SIZE
Definition: adts_parser.h:25
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:28
ff_parse_close
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:289
FTRParseContext::skip
int skip
Definition: ftr_parser.c:34
FTRParseContext::split
int split
Definition: ftr_parser.c:35
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:313
AV_WB64
#define AV_WB64(p, v)
Definition: intreadwrite.h:431
ParseContext
Definition: parser.h:28
mpeg4audio.h
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:1065
AACADTSHeaderInfo::chan_config
uint8_t chan_config
Definition: adts_header.h:42
ff_adts_header_parse_buf
int ff_adts_header_parse_buf(const uint8_t buf[AV_AAC_ADTS_HEADER_SIZE+AV_INPUT_BUFFER_PADDING_SIZE], AACADTSHeaderInfo *hdr)
Wrapper around ff_adts_header_parse() for users that don't already have a suitable GetBitContext.
Definition: adts_header.c:76
s
#define s(width, name)
Definition: cbs_vp9.c:198
FTRParseContext
Definition: ftr_parser.c:32
FTRParseContext::frame_index
int frame_index
Definition: ftr_parser.c:36
NULL
#define NULL
Definition: coverity.c:32
AVCodecParser::codec_ids
int codec_ids[7]
Definition: avcodec.h:2868
size
int size
Definition: twinvq_data.h:10344
ff_combine_frame
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:203
PARSER_FLAG_COMPLETE_FRAMES
#define PARSER_FLAG_COMPLETE_FRAMES
Definition: avcodec.h:2742
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
FTRParseContext::pc
ParseContext pc
Definition: ftr_parser.c:33
state
static struct @416 state
parser.h
AVCodecParserContext
Definition: avcodec.h:2708
ftr_parse
static int ftr_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: ftr_parser.c:39
adts_parser.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
AVCodecContext
main external API structure.
Definition: avcodec.h:445
ff_mpeg4audio_channels
const uint8_t ff_mpeg4audio_channels[15]
Definition: mpeg4audio.c:59
ParseContext::state64
uint64_t state64
contains the last 8 bytes in MSB order
Definition: parser.h:37
ff_ftr_parser
const AVCodecParser ff_ftr_parser
Definition: ftr_parser.c:99
adts_header.h
END_NOT_FOUND
#define END_NOT_FOUND
Definition: parser.h:40
AVCodecParser
Definition: avcodec.h:2867
AV_CODEC_ID_FTR
@ AV_CODEC_ID_FTR
Definition: codec_id.h:540
AACADTSHeaderInfo
Definition: adts_header.h:35