FFmpeg
wvedec.c
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1 /*
2  * Copyright (c) 2015 Paul B Mahol
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "avformat.h"
22 #include "internal.h"
23 #include "pcm.h"
24 
25 static int wve_probe(const AVProbeData *p)
26 {
27  if (memcmp(p->buf, "ALawSoundFile**\0\017\020", 18) ||
28  memcmp(p->buf + 22, "\0\0\0\1\0\0\0\0\0\0", 10))
29  return 0;
30  return AVPROBE_SCORE_MAX;
31 }
32 
34 {
35  AVStream *st;
36 
37  st = avformat_new_stream(s, NULL);
38  if (!st)
39  return AVERROR(ENOMEM);
40 
41  avio_skip(s->pb, 18);
42  st->duration = avio_rb32(s->pb);
45  st->codecpar->sample_rate = 8000;
46  st->codecpar->channels = 1;
49  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
50  avio_skip(s->pb, 10);
51 
52  return 0;
53 }
54 
56  .name = "wve",
57  .long_name = NULL_IF_CONFIG_SMALL("Psion 3 audio"),
58  .read_probe = wve_probe,
59  .read_header = wve_read_header,
60  .read_packet = ff_pcm_read_packet,
61  .read_seek = ff_pcm_read_seek,
62 };
#define NULL
Definition: coverity.c:32
static int wve_probe(const AVProbeData *p)
Definition: wvedec.c:25
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:4930
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3971
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
Format I/O context.
Definition: avformat.h:1358
static int wve_read_header(AVFormatContext *s)
Definition: wvedec.c:33
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:803
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4503
int av_get_bits_per_sample(enum AVCodecID codec_id)
Return codec bits per sample.
Definition: utils.c:1533
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3967
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
int block_align
Audio only.
Definition: avcodec.h:4088
AVInputFormat ff_wve_demuxer
Definition: wvedec.c:55
#define s(width, name)
Definition: cbs_vp9.c:257
int ff_pcm_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: pcm.c:52
Stream structure.
Definition: avformat.h:881
int ff_pcm_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: pcm.c:29
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4081
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4013
int channels
Audio only.
Definition: avcodec.h:4077
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
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