FFmpeg: libavformat/ivfdec.c Source File

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libavformat

ivfdec.c

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1 /*

3 *

4 * This file is part of FFmpeg.

5 *

6 * FFmpeg is free software; you can redistribute it and/or

7 * modify it under the terms of the GNU Lesser General Public

8 * License as published by the Free Software Foundation; either

9 * version 2.1 of the License, or (at your option) any later version.

10 *

11 * FFmpeg is distributed in the hope that it will be useful,

12 * but WITHOUT ANY WARRANTY; without even the implied warranty of

13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

14 * Lesser General Public License for more details.

15 *

16 * You should have received a copy of the GNU Lesser General Public

17 * License along with FFmpeg; if not, write to the Free Software

18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

19 */

21 #include "avformat.h"

22 #include "internal.h"

23 #include "riff.h"

24 #include "libavutil/intreadwrite.h"

26 static int probe(AVProbeData *p)

27 {

28 if (AV_RL32(p->buf) == MKTAG('D','K','I','F')

29 && !AV_RL16(p->buf+4) && AV_RL16(p->buf+6) == 32)

30 return AVPROBE_SCORE_MAX-2;

32 return 0;

33 }

35 static int read_header(AVFormatContext *s)

36 {

37 AVStream *st;

38 AVRational time_base;

40 avio_rl32(s->pb); // DKIF

41 avio_rl16(s->pb); // version

42 avio_rl16(s->pb); // header size

44 st = avformat_new_stream(s, NULL);

45 if (!st)

46 return AVERROR(ENOMEM);

49 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

50 st->codec->codec_tag = avio_rl32(s->pb);

51 st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, st->codec->codec_tag);

52 st->codec->width = avio_rl16(s->pb);

53 st->codec->height = avio_rl16(s->pb);

54 time_base.den = avio_rl32(s->pb);

55 time_base.num = avio_rl32(s->pb);

56 st->duration = avio_rl64(s->pb);

58 st->need_parsing = AVSTREAM_PARSE_HEADERS;

60 if (!time_base.den || !time_base.num) {

61 av_log(s, AV_LOG_ERROR, "Invalid frame rate\n");

62 return AVERROR_INVALIDDATA;

63 }

65 avpriv_set_pts_info(st, 64, time_base.num, time_base.den);

67 return 0;

68 }

70 static int read_packet(AVFormatContext *s, AVPacket *pkt)

71 {

72 int ret, size = avio_rl32(s->pb);

73 int64_t pts = avio_rl64(s->pb);

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

76 pkt->stream_index = 0;

77 pkt->pts = pts;

78 pkt->pos -= 12;

80 return ret;

81 }

83 AVInputFormat ff_ivf_demuxer = {

84 .name = "ivf",

85 .long_name = NULL_IF_CONFIG_SMALL("On2 IVF"),

86 .read_probe = probe,

87 .read_header = read_header,

88 .read_packet = read_packet,

89 .flags = AVFMT_GENERIC_INDEX,

90 .codec_tag = (const AVCodecTag* const []){ ff_codec_bmp_tags, 0 },

91 };

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