pvfdec.c
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1 /*
2  * PVF demuxer
3  * Copyright (c) 2012 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 "avformat.h"
23 #include "internal.h"
24 #include "pcm.h"
25 
26 static int pvf_probe(AVProbeData *p)
27 {
28  if (!memcmp(p->buf, "PVF1\n", 5))
29  return AVPROBE_SCORE_MAX;
30  return 0;
31 }
32 
34 {
35  char buffer[32];
36  AVStream *st;
37  int bps, channels, sample_rate;
38 
39  avio_skip(s->pb, 5);
40  ff_get_line(s->pb, buffer, sizeof(buffer));
41  if (sscanf(buffer, "%d %d %d",
42  &channels,
43  &sample_rate,
44  &bps) != 3)
45  return AVERROR_INVALIDDATA;
46 
47  if (channels <= 0 || bps <= 0 || sample_rate <= 0)
48  return AVERROR_INVALIDDATA;
49 
50  st = avformat_new_stream(s, NULL);
51  if (!st)
52  return AVERROR(ENOMEM);
53 
55  st->codec->channels = channels;
57  st->codec->codec_id = ff_get_pcm_codec_id(bps, 0, 1, 0xFFFF);
59  st->codec->block_align = bps * st->codec->channels / 8;
60 
61  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
62 
63  return 0;
64 }
65 
67  .name = "pvf",
68  .long_name = NULL_IF_CONFIG_SMALL("PVF (Portable Voice Format)"),
69  .read_probe = pvf_probe,
70  .read_header = pvf_read_header,
71  .read_packet = ff_pcm_read_packet,
72  .read_seek = ff_pcm_read_seek,
73  .extensions = "pvf",
74  .flags = AVFMT_GENERIC_INDEX,
75 };
const char * s
Definition: avisynth_c.h:668
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
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.
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:256
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
static int pvf_read_header(AVFormatContext *s)
Definition: pvfdec.c:33
Format I/O context.
Definition: avformat.h:944
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
static int pvf_probe(AVProbeData *p)
Definition: pvfdec.c:26
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:662
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:336
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:618
int ff_pcm_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Stream structure.
Definition: avformat.h:643
int ff_pcm_read_packet(AVFormatContext *s, AVPacket *pkt)
NULL
Definition: eval.c:55
AVInputFormat ff_pvf_demuxer
Definition: pvfdec.c:66
sample_rate
enum AVMediaType codec_type
enum AVCodecID codec_id
int sample_rate
samples per second
AVIOContext * pb
I/O context.
Definition: avformat.h:977
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:353
enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags)
Select a PCM codec based on the given parameters.
This structure contains the data a format has to probe a file.
Definition: avformat.h:334
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFilterBuffer 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.Buffer references ownership and permissions
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:340
Main libavformat public API header.
the buffer and buffer reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFilterBuffer structures They must not be accessed but through references stored in AVFilterBufferRef structures Several references can point to the same buffer
unsigned bps
Definition: movenc.c:895
int channels
number of audio channels
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:461