FFmpeg
ftr_parser.c
Go to the documentation of this file.
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 "get_bits.h"
29 #include "adts_header.h"
30 #include "adts_parser.h"
31 #include "mpeg4audio.h"
32 
33 typedef struct FTRParseContext {
35  int skip;
36  int split;
39 
41  const uint8_t **poutbuf, int *poutbuf_size,
42  const uint8_t *buf, int buf_size)
43 {
44  uint8_t tmp[8 + AV_INPUT_BUFFER_PADDING_SIZE];
45  FTRParseContext *ftr = s->priv_data;
46  uint64_t state = ftr->pc.state64;
47  int next = END_NOT_FOUND;
50  int size;
51 
52  *poutbuf_size = 0;
53  *poutbuf = NULL;
54 
55  if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
56  next = buf_size;
57  } else {
58  for (int i = 0; i < buf_size; i++) {
59  if (ftr->skip > 0) {
60  ftr->skip--;
61  if (ftr->skip == 0 && ftr->split) {
62  ftr->split = 0;
63  next = i;
64  s->duration = 1024;
65  s->key_frame = 1;
66  break;
67  } else if (ftr->skip > 0) {
68  continue;
69  }
70  }
71 
72  state = (state << 8) | buf[i];
73  AV_WB64(tmp, state);
76 
77  if ((size = ff_adts_header_parse(&bits, &hdr)) > 0) {
78  ftr->skip = size - 6;
80  if (ftr->frame_index >= avctx->ch_layout.nb_channels) {
81  ftr->frame_index = 0;
82  ftr->split = 1;
83  }
84  }
85  }
86 
87  ftr->pc.state64 = state;
88 
89  if (ff_combine_frame(&ftr->pc, next, &buf, &buf_size) < 0) {
90  *poutbuf = NULL;
91  *poutbuf_size = 0;
92  return buf_size;
93  }
94  }
95 
96  *poutbuf = buf;
97  *poutbuf_size = buf_size;
98 
99  return next;
100 }
101 
103  .codec_ids = { AV_CODEC_ID_FTR },
104  .priv_data_size = sizeof(FTRParseContext),
105  .parser_parse = ftr_parse,
106  .parser_close = ff_parse_close,
107 };
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:284
FTRParseContext::skip
int skip
Definition: ftr_parser.c:35
FTRParseContext::split
int split
Definition: ftr_parser.c:36
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:311
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:649
AV_WB64
#define AV_WB64(p, v)
Definition: intreadwrite.h:433
ParseContext
Definition: parser.h:28
mpeg4audio.h
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2059
ff_adts_header_parse
int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr)
Parse the ADTS frame header to the end of the variable header, which is the first 54 bits.
Definition: adts_header.c:30
GetBitContext
Definition: get_bits.h:61
AACADTSHeaderInfo::chan_config
uint8_t chan_config
Definition: adts_header.h:35
s
#define s(width, name)
Definition: cbs_vp9.c:256
FTRParseContext
Definition: ftr_parser.c:33
bits
uint8_t bits
Definition: vp3data.h:128
get_bits.h
state
static struct @344 state
FTRParseContext::frame_index
int frame_index
Definition: ftr_parser.c:37
NULL
#define NULL
Definition: coverity.c:32
AVCodecParser::codec_ids
int codec_ids[7]
Definition: avcodec.h:2960
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:199
PARSER_FLAG_COMPLETE_FRAMES
#define PARSER_FLAG_COMPLETE_FRAMES
Definition: avcodec.h:2834
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
FTRParseContext::pc
ParseContext pc
Definition: ftr_parser.c:34
parser.h
AVCodecParserContext
Definition: avcodec.h:2800
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:40
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:398
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:102
adts_header.h
END_NOT_FOUND
#define END_NOT_FOUND
Definition: parser.h:40
AVCodecParser
Definition: avcodec.h:2959
AV_CODEC_ID_FTR
@ AV_CODEC_ID_FTR
Definition: codec_id.h:535
AACADTSHeaderInfo
Definition: adts_header.h:28