FFmpeg
adp.c
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1 /*
2  * ADP demuxer
3  * Copyright (c) 2013 James Almer
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 
23 #include "libavutil/intreadwrite.h"
24 #include "avformat.h"
25 #include "internal.h"
26 
27 static int adp_probe(const AVProbeData *p)
28 {
29  int i, changes = 0;
30  uint8_t last = 0;
31 
32  if (p->buf_size < 32)
33  return 0;
34 
35  for (i = 0; i < p->buf_size - 3; i+=32) {
36  if (p->buf[i] != p->buf[i+2] || p->buf[i+1] != p->buf[i+3])
37  return 0;
38  if (p->buf[i] != last)
39  changes++;
40  last = p->buf[i];
41  }
42  if (changes <= 1)
43  return 0;
44 
45  return p->buf_size < 260 ? 1 : AVPROBE_SCORE_MAX / 4;
46 }
47 
49 {
50  AVStream *st;
51 
52  st = avformat_new_stream(s, NULL);
53  if (!st)
54  return AVERROR(ENOMEM);
55 
59  st->codecpar->channels = 2;
60  st->codecpar->sample_rate = 48000;
61  st->start_time = 0;
64 
65  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
66 
67  return 0;
68 }
69 
71 {
72  int ret, size = 1024;
73 
74  if (avio_feof(s->pb))
75  return AVERROR_EOF;
76 
77  ret = av_get_packet(s->pb, pkt, size);
78 
79  if (ret != size) {
80  if (ret < 0) {
81  av_packet_unref(pkt);
82  return ret;
83  }
84  av_shrink_packet(pkt, ret);
85  }
86  pkt->stream_index = 0;
87 
88  return ret;
89 }
90 
92  .name = "adp",
93  .long_name = NULL_IF_CONFIG_SMALL("ADP"),
94  .read_probe = adp_probe,
95  .read_header = adp_read_header,
96  .read_packet = adp_read_packet,
97  .extensions = "adp,dtk",
98 };
static int adp_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: adp.c:70
#define NULL
Definition: coverity.c:32
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:339
AVInputFormat ff_adp_demuxer
Definition: adp.c:91
void av_shrink_packet(AVPacket *pkt, int size)
Reduce packet size, correctly zeroing padding.
Definition: avpacket.c:101
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:4896
static int adp_read_header(AVFormatContext *s)
Definition: adp.c:48
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3960
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
Format I/O context.
Definition: avformat.h:1358
uint8_t
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4469
#define AVERROR_EOF
End of file.
Definition: error.h:55
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
ptrdiff_t size
Definition: opengl_enc.c:100
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4062
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
static int adp_probe(const AVProbeData *p)
Definition: adp.c:27
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3956
int av_get_audio_frame_duration2(AVCodecParameters *par, int frame_bytes)
This function is the same as av_get_audio_frame_duration(), except it works with AVCodecParameters in...
Definition: utils.c:1730
This document is a tutorial initiation for writing simple filters in libavfilter libavfilter is which means that it is highly recommended that you submit your filters to the FFmpeg development mailing list and make sure that they are applied your filters are likely to have a very short lifetime due to more or less regular internal API changes
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:260
audio channel layout utility functions
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:881
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:599
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:4070
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:920
int channels
Audio only.
Definition: avcodec.h:4066
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
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
int stream_index
Definition: avcodec.h:1482
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
This structure stores compressed data.
Definition: avcodec.h:1457