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loasdec.c
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1 /*
2  * LOAS AudioSyncStream demuxer
3  * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
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 #include "libavutil/intreadwrite.h"
23 #include "libavutil/internal.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "rawdec.h"
27 
28 #define LOAS_SYNC_WORD 0x2b7
29 
30 static int loas_probe(AVProbeData *p)
31 {
32  int max_frames = 0, first_frames = 0;
33  int fsize, frames;
34  const uint8_t *buf0 = p->buf;
35  const uint8_t *buf2;
36  const uint8_t *buf;
37  const uint8_t *end = buf0 + p->buf_size - 3;
38  buf = buf0;
39 
40  for (; buf < end; buf = buf2 + 1) {
41  buf2 = buf;
42 
43  for (frames = 0; buf2 < end; frames++) {
44  uint32_t header = AV_RB24(buf2);
45  if ((header >> 13) != LOAS_SYNC_WORD)
46  break;
47  fsize = (header & 0x1FFF) + 3;
48  if (fsize < 7)
49  break;
50  fsize = FFMIN(fsize, end - buf2);
51  buf2 += fsize;
52  }
53  max_frames = FFMAX(max_frames, frames);
54  if (buf == buf0)
55  first_frames = frames;
56  }
57 
58  if (first_frames >= 3)
59  return AVPROBE_SCORE_EXTENSION + 1;
60  else if (max_frames > 100)
62  else if (max_frames >= 3)
63  return AVPROBE_SCORE_EXTENSION / 2;
64  else
65  return 0;
66 }
67 
69 {
70  AVStream *st;
71 
72  st = avformat_new_stream(s, NULL);
73  if (!st)
74  return AVERROR(ENOMEM);
75 
79 
80  //LCM of all possible AAC sample rates
81  avpriv_set_pts_info(st, 64, 1, 28224000);
82 
83  return 0;
84 }
85 
87  .name = "loas",
88  .long_name = NULL_IF_CONFIG_SMALL("LOAS AudioSyncStream"),
89  .read_probe = loas_probe,
90  .read_header = loas_read_header,
91  .read_packet = ff_raw_read_partial_packet,
92  .flags= AVFMT_GENERIC_INDEX,
93  .raw_codec_id = AV_CODEC_ID_AAC_LATM,
94 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
static int loas_read_header(AVFormatContext *s)
Definition: loasdec.c:68
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4581
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3981
Format I/O context.
Definition: avformat.h:1338
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
enum AVStreamParseType need_parsing
Definition: avformat.h:1076
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4214
#define LOAS_SYNC_WORD
Definition: loasdec.c:28
static const uint8_t header[24]
Definition: sdr2.c:67
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:814
#define AVERROR(e)
Definition: error.h:43
int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawdec.c:35
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3977
#define FFMAX(a, b)
Definition: common.h:94
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:464
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:463
common internal API header
#define FFMIN(a, b)
Definition: common.h:96
int frames
Definition: movenc.c:65
Stream structure.
Definition: avformat.h:889
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:87
static int loas_probe(AVProbeData *p)
Definition: loasdec.c:30
void * buf
Definition: avisynth_c.h:690
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:487
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:471
This structure contains the data a format has to probe a file.
Definition: avformat.h:461
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:710
Main libavformat public API header.
struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1350
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:664
AVCodecParameters * codecpar
Definition: avformat.h:1241
static int64_t fsize(FILE *f)
Definition: audiomatch.c:28
AVInputFormat ff_loas_demuxer
Definition: loasdec.c:86