FFmpeg: libavformat/afc.c Source File

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libavformat

afc.c

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1 /*

2 * AFC demuxer

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 */

22 #include "libavutil/channel_layout.h"

23 #include "avformat.h"

24 #include "internal.h"

26 typedef struct AFCDemuxContext {

27 int64_t data_end;

28 } AFCDemuxContext;

30 static int afc_read_header(AVFormatContext *s)

31 {

32 AFCDemuxContext *c = s->priv_data;

33 AVStream *st;

35 st = avformat_new_stream(s, NULL);

36 if (!st)

37 return AVERROR(ENOMEM);

38 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

39 st->codec->codec_id = AV_CODEC_ID_ADPCM_AFC;

40 st->codec->channels = 2;

41 st->codec->channel_layout = AV_CH_LAYOUT_STEREO;

43 if (ff_alloc_extradata(st->codec, 1))

44 return AVERROR(ENOMEM);

45 st->codec->extradata[0] = 8 * st->codec->channels;

47 c->data_end = avio_rb32(s->pb) + 32LL;

48 st->duration = avio_rb32(s->pb);

49 st->codec->sample_rate = avio_rb16(s->pb);

50 avio_skip(s->pb, 22);

51 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

53 return 0;

54 }

56 static int afc_read_packet(AVFormatContext *s, AVPacket *pkt)

57 {

58 AFCDemuxContext *c = s->priv_data;

59 int64_t size;

60 int ret;

62 size = FFMIN(c->data_end - avio_tell(s->pb), 18 * 128);

63 if (size <= 0)

64 return AVERROR_EOF;

66 ret = av_get_packet(s->pb, pkt, size);

67 pkt->stream_index = 0;

68 return ret;

69 }

71 AVInputFormat ff_afc_demuxer = {

72 .name = "afc",

73 .long_name = NULL_IF_CONFIG_SMALL("AFC"),

74 .priv_data_size = sizeof(AFCDemuxContext),

75 .read_header = afc_read_header,

76 .read_packet = afc_read_packet,

77 .extensions = "afc",

78 .flags = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK,

79 };

NULL

#define NULL

Definition: coverity.c:32

AVFMT_NOBINSEARCH

#define AVFMT_NOBINSEARCH

Format does not allow to fall back on binary search via read_timestamp.

Definition: avformat.h:491

const char * s

Definition: avisynth_c.h:631

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:4149

avio_skip

int64_t avio_skip(AVIOContext *s, int64_t offset)

Skip given number of bytes forward.

Definition: aviobuf.c:282

AVInputFormat

Definition: avformat.h:656

pkt

static AVPacket pkt

Definition: demuxing_decoding.c:54

AV_CH_LAYOUT_STEREO

#define AV_CH_LAYOUT_STEREO

Definition: channel_layout.h:86

avio_rb16

unsigned int avio_rb16(AVIOContext *s)

Definition: aviobuf.c:683

AVFormatContext

Format I/O context.

Definition: avformat.h:1314

AV_CODEC_ID_ADPCM_AFC

Definition: avcodec.h:393

avio_rb32

unsigned int avio_rb32(AVIOContext *s)

Definition: aviobuf.c:698

AFCDemuxContext

Definition: afc.c:26

AVCodecContext::extradata

uint8_t * extradata

some codecs need / can use extradata like Huffman tables.

Definition: avcodec.h:1647

avformat_new_stream

AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)

Add a new stream to a media file.

Definition: utils.c:3805

afc_read_header

static int afc_read_header(AVFormatContext *s)

Definition: afc.c:30

AVERROR_EOF

#define AVERROR_EOF

End of file.

Definition: error.h:55

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:252

size

ptrdiff_t size

Definition: opengl_enc.c:101

avio_tell

static av_always_inline int64_t avio_tell(AVIOContext *s)

ftell() equivalent for AVIOContext.

Definition: avio.h:442

AVERROR

#define AVERROR(e)

Definition: error.h:43

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:176

AVMEDIA_TYPE_AUDIO

Definition: avutil.h:194

internal.h

AVCodecContext::channel_layout

uint64_t channel_layout

Audio channel layout.

Definition: avcodec.h:2338

AVStream::codec

AVCodecContext * codec

Codec context associated with this stream.

Definition: avformat.h:896

channel_layout.h

audio channel layout utility functions

FFMIN

#define FFMIN(a, b)

Definition: common.h:96

AFCDemuxContext::data_end

int64_t data_end

Definition: afc.c:27

read_header

static int read_header(FFV1Context *f)

Definition: ffv1dec.c:638

AVStream

Stream structure.

Definition: avformat.h:877

read_packet

static int read_packet(void *opaque, uint8_t *buf, int buf_size)

Definition: avio_reading.c:42

AVCodecContext::codec_type

enum AVMediaType codec_type

Definition: avcodec.h:1540

AVCodecContext::codec_id

enum AVCodecID codec_id

Definition: avcodec.h:1549

AVCodecContext::sample_rate

int sample_rate

samples per second

Definition: avcodec.h:2287

AVFormatContext::pb

AVIOContext * pb

I/O context.

Definition: avformat.h:1356

afc_read_packet

static int afc_read_packet(AVFormatContext *s, AVPacket *pkt)

Definition: afc.c:56

AVFMT_NOGENSEARCH

#define AVFMT_NOGENSEARCH

Format does not allow to fall back on generic search.

Definition: avformat.h:492

ff_alloc_extradata

int ff_alloc_extradata(AVCodecContext *avctx, int size)

Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0...

Definition: utils.c:2979

flags

static int flags

Definition: cpu.c:47

ff_afc_demuxer

AVInputFormat ff_afc_demuxer

Definition: afc.c:71

AVStream::duration

int64_t duration

Decoding: duration of the stream, in stream time base.

Definition: avformat.h:936

avformat.h

Main libavformat public API header.

static double c[64]

Definition: vsrc_mptestsrc.c:87

AVFMT_NO_BYTE_SEEK

#define AVFMT_NO_BYTE_SEEK

Format does not allow seeking by bytes.

Definition: avformat.h:493

AVCodecContext::channels

int channels

number of audio channels

Definition: avcodec.h:2288

AVFormatContext::priv_data

void * priv_data

Format private data.

Definition: avformat.h:1342

AVInputFormat::name

const char * name

A comma separated list of short names for the format.

Definition: avformat.h:661

AVPacket::stream_index

int stream_index

Definition: avcodec.h:1469

AVPacket

This structure stores compressed data.

Definition: avcodec.h:1444

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