FFmpeg
apac.c
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1 /*
2  * APAC demuxer
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 #include "libavutil/intreadwrite.h"
23 #include "avformat.h"
24 #include "demux.h"
25 #include "internal.h"
26 #include "rawdec.h"
27 
28 static int apac_probe(const AVProbeData *p)
29 {
30  if (AV_RB32(p->buf) == MKBETAG('A','P','A','C') &&
31  AV_RB32(p->buf + 8) == MKBETAG('P','R','O','F') &&
32  AV_RB32(p->buf + 12) == MKBETAG('N','A','D',' '))
33  return AVPROBE_SCORE_MAX;
34 
35  return 0;
36 }
37 
38 static int apac_read_header(AVFormatContext *s)
39 {
40  AVIOContext *pb = s->pb;
41  uint32_t chunk_size;
42  AVStream *st;
43  int64_t pos;
44 
45  avio_skip(pb, 16);
46  chunk_size = avio_rl32(pb);
47  avio_skip(pb, chunk_size);
48  if (avio_rb32(pb) != MKBETAG('P','F','M','T'))
49  return AVERROR_INVALIDDATA;
50  chunk_size = avio_rl32(pb);
51  pos = avio_tell(pb);
52  avio_skip(pb, 2);
53  st = avformat_new_stream(s, NULL);
54  if (!st)
55  return AVERROR(ENOMEM);
56  st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
57  st->codecpar->codec_id = AV_CODEC_ID_APAC;
58  st->codecpar->ch_layout.nb_channels = avio_rl16(pb);
59  st->codecpar->sample_rate = avio_rl32(pb);
60  if (st->codecpar->ch_layout.nb_channels <= 0 ||
61  st->codecpar->ch_layout.nb_channels > 2 ||
62  st->codecpar->sample_rate <= 0)
63  return AVERROR_INVALIDDATA;
64  avio_skip(pb, 2);
65  st->codecpar->bits_per_coded_sample = avio_rl16(pb);
66  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
67  avio_skip(pb, (chunk_size + pos) - avio_tell(pb) + (chunk_size & 1));
68  if (avio_rb32(pb) != MKBETAG('P','A','D',' '))
69  return AVERROR_INVALIDDATA;
70  avio_skip(pb, 4);
71 
72  return 0;
73 }
74 
75 const AVInputFormat ff_apac_demuxer = {
76  .name = "apac",
77  .long_name = NULL_IF_CONFIG_SMALL("raw APAC"),
78  .read_probe = apac_probe,
79  .read_header = apac_read_header,
80  .read_packet = ff_raw_read_partial_packet,
81  .extensions = "apc",
82  .flags = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,
83  .raw_codec_id = AV_CODEC_ID_APAC,
84  .priv_data_size = sizeof(FFRawDemuxerContext),
85  .priv_class = &ff_raw_demuxer_class,
86 };
AV_CODEC_ID_APAC
@ AV_CODEC_ID_APAC
Definition: codec_id.h:541
AVFMT_NO_BYTE_SEEK
#define AVFMT_NO_BYTE_SEEK
Format does not allow seeking by bytes.
Definition: avformat.h:488
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:480
AVFMT_NOBINSEARCH
#define AVFMT_NOBINSEARCH
Format does not allow to fall back on binary search via read_timestamp.
Definition: avformat.h:486
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:317
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:464
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:761
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:513
FFRawDemuxerContext
Definition: rawdec.h:36
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:761
apac_read_header
static int apac_read_header(AVFormatContext *s)
Definition: apac.c:38
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:808
AVInputFormat
Definition: avformat.h:549
ff_raw_read_partial_packet
int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawdec.c:32
ff_apac_demuxer
const AVInputFormat ff_apac_demuxer
Definition: apac.c:75
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:554
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:454
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
ff_raw_demuxer_class
const AVClass ff_raw_demuxer_class
Definition: rawdec.c:140
AVFormatContext
Format I/O context.
Definition: avformat.h:1115
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
apac_probe
static int apac_probe(const AVProbeData *p)
Definition: apac.c:28
NULL
#define NULL
Definition: coverity.c:32
rawdec.h
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:452
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:206
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:171
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:777
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:106
MKBETAG
#define MKBETAG(a, b, c, d)
Definition: macros.h:56
AV_RB32
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_RB32
Definition: bytestream.h:96
demux.h
AVStream
Stream structure.
Definition: avformat.h:841
pos
unsigned int pos
Definition: spdifenc.c:413
avformat.h
AVFMT_NOGENSEARCH
#define AVFMT_NOGENSEARCH
Format does not allow to fall back on generic search.
Definition: avformat.h:487
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:365
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:97
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
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