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 };

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