FFmpeg
acedec.c
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1 /*
2  * ACE demuxer
3  * Copyright (c) 2020 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 "internal.h"
25 
26 static int ace_probe(const AVProbeData *p)
27 {
28  uint32_t asc;
29 
30  if (AV_RB32(p->buf) != MKBETAG('A','A','C',' '))
31  return 0;
32  if (p->buf_size < 0x44)
33  return 0;
34  asc = AV_RB32(p->buf + 0x40);
35  if (asc < 0x44 || asc > p->buf_size - 4)
36  return 0;
37  if (AV_RB32(p->buf + asc) != MKBETAG('A','S','C',' '))
38  return 0;
39 
40  return AVPROBE_SCORE_MAX / 2 + 1;
41 }
42 
44 {
45  AVIOContext *pb = s->pb;
46  AVCodecParameters *par;
47  int ret, codec, rate, nb_channels;
48  uint32_t asc_pos, size;
49  AVStream *st;
50 
51  avio_skip(pb, 0x40);
52  asc_pos = avio_rb32(pb);
53  if (asc_pos < 0x44)
54  return AVERROR_INVALIDDATA;
55  avio_skip(pb, asc_pos - 0x44);
56  if (avio_rb32(pb) != MKBETAG('A','S','C',' '))
57  return AVERROR_INVALIDDATA;
58  avio_skip(pb, 0xec);
59  codec = avio_rb32(pb);
60  nb_channels = avio_rb32(pb);
61  if (nb_channels <= 0 || nb_channels > 8)
62  return AVERROR_INVALIDDATA;
63  size = avio_rb32(pb);
64  if (size == 0)
65  return AVERROR_INVALIDDATA;
66  rate = avio_rb32(pb);
67  if (rate <= 0)
68  return AVERROR_INVALIDDATA;
69  avio_skip(pb, 16);
70 
71  st = avformat_new_stream(s, NULL);
72  if (!st)
73  return AVERROR(ENOMEM);
74  st->start_time = 0;
75  par = st->codecpar;
77  par->channels = nb_channels;
78  par->sample_rate = rate;
79  par->block_align = (codec == 4 ? 0x60 : codec == 5 ? 0x98 : 0xC0) * nb_channels;
80  st->duration = (size / par->block_align) * 1024LL;
82 
83  ret = ff_alloc_extradata(par, 14);
84  if (ret < 0)
85  return ret;
86 
87  AV_WL16(st->codecpar->extradata, 1);
88  AV_WL16(st->codecpar->extradata+2, 2048 * par->channels);
89  AV_WL16(st->codecpar->extradata+4, 0);
90  AV_WL16(st->codecpar->extradata+6, codec == 4 ? 1 : 0);
91  AV_WL16(st->codecpar->extradata+8, codec == 4 ? 1 : 0);
92  AV_WL16(st->codecpar->extradata+10, 1);
93  AV_WL16(st->codecpar->extradata+12, 0);
94 
95  avpriv_set_pts_info(st, 64, 1, par->sample_rate);
96 
97  return 0;
98 }
99 
101 {
102  AVCodecParameters *par = s->streams[0]->codecpar;
103 
104  return av_get_packet(s->pb, pkt, par->block_align);
105 }
106 
108  .name = "ace",
109  .long_name = NULL_IF_CONFIG_SMALL("tri-Ace Audio Container"),
110  .read_probe = ace_probe,
111  .read_header = ace_read_header,
112  .read_packet = ace_read_packet,
113  .flags = AVFMT_GENERIC_INDEX,
114 };
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4547
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
ace_probe
static int ace_probe(const AVProbeData *p)
Definition: acedec.c:26
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:922
AV_CODEC_ID_ATRAC3
@ AV_CODEC_ID_ATRAC3
Definition: codec_id.h:455
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:781
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:640
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVFormatContext
Format I/O context.
Definition: avformat.h:1231
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
ace_read_header
static int ace_read_header(AVFormatContext *s)
Definition: acedec.c:43
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
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:117
ff_ace_demuxer
AVInputFormat ff_ace_demuxer
Definition: acedec.c:107
avpriv_set_pts_info
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:4993
size
int size
Definition: twinvq_data.h:10344
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
MKBETAG
#define MKBETAG(a, b, c, d)
Definition: common.h:479
AV_WL16
#define AV_WL16(p, v)
Definition: intreadwrite.h:412
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:177
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:310
ace_read_packet
static int ace_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: acedec.c:100
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:873
avformat.h
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:337
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:346
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:912
ff_alloc_extradata
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0.
Definition: utils.c:3368
nb_channels
int nb_channels
Definition: channel_layout.c:81