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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(AVProbeData *p)
28 {
29  int i, changes = 0;
30  char 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->codec->channels = 2;
60  st->codec->sample_rate = 48000;
61  st->start_time = 0;
62  if (s->pb->seekable)
64 
65  avpriv_set_pts_info(st, 64, 1, st->codec->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_free_packet(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
const char * s
Definition: avisynth_c.h:631
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:281
void av_free_packet(AVPacket *pkt)
Free a packet.
Definition: avpacket.c:280
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:103
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:4006
static int adp_read_header(AVFormatContext *s)
Definition: adp.c:48
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
Format I/O context.
Definition: avformat.h:1272
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3672
#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:241
ptrdiff_t size
Definition: opengl_enc.c:101
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2046
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:861
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:451
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:450
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:160
audio channel layout utility functions
ret
Definition: avfilter.c:974
static int adp_probe(AVProbeData *p)
Definition: adp.c:27
Stream structure.
Definition: avformat.h:842
enum AVMediaType codec_type
Definition: avcodec.h:1249
enum AVCodecID codec_id
Definition: avcodec.h:1258
int sample_rate
samples per second
Definition: avcodec.h:1985
AVIOContext * pb
I/O context.
Definition: avformat.h:1314
This structure contains the data a format has to probe a file.
Definition: avformat.h:448
int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)
Return audio frame duration.
Definition: utils.c:3336
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:901
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:460
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:894
int channels
number of audio channels
Definition: avcodec.h:1986
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:628
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:300
int stream_index
Definition: avcodec.h:1164
This structure stores compressed data.
Definition: avcodec.h:1139