FFmpeg: libavformat/vc1test.c Source File

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libavformat

vc1test.c

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1 /*

2 * VC1 Test Bitstreams Format 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 /**

23 * @file

24 * VC1 test bitstream file demuxer

25 * by Konstantin Shishkov

26 * Format specified in SMPTE standard 421 Annex L

27 */

29 #include "libavutil/intreadwrite.h"

30 #include "avformat.h"

31 #include "internal.h"

33 #define VC1_EXTRADATA_SIZE 4

35 static int vc1t_probe(AVProbeData *p)

36 {

37 if (p->buf_size < 24)

38 return 0;

39 if (p->buf[3] != 0xC5 || AV_RL32(&p->buf[4]) != 4 || AV_RL32(&p->buf[20]) != 0xC)

40 return 0;

42 return AVPROBE_SCORE_EXTENSION;

43 }

45 static int vc1t_read_header(AVFormatContext *s)

46 {

47 AVIOContext *pb = s->pb;

48 AVStream *st;

49 int frames;

50 uint32_t fps;

52 frames = avio_rl24(pb);

53 if(avio_r8(pb) != 0xC5 || avio_rl32(pb) != 4)

54 return AVERROR_INVALIDDATA;

56 /* init video codec */

57 st = avformat_new_stream(s, NULL);

58 if (!st)

59 return AVERROR(ENOMEM);

61 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

62 st->codec->codec_id = AV_CODEC_ID_WMV3;

64 if (ff_get_extradata(st->codec, pb, VC1_EXTRADATA_SIZE) < 0)

65 return AVERROR(ENOMEM);

66 st->codec->height = avio_rl32(pb);

67 st->codec->width = avio_rl32(pb);

68 if(avio_rl32(pb) != 0xC)

69 return AVERROR_INVALIDDATA;

70 avio_skip(pb, 8);

71 fps = avio_rl32(pb);

72 if(fps == 0xFFFFFFFF)

73 avpriv_set_pts_info(st, 32, 1, 1000);

74 else{

75 if (!fps) {

76 av_log(s, AV_LOG_ERROR, "Zero FPS specified, defaulting to 1 FPS\n");

77 fps = 1;

78 }

79 avpriv_set_pts_info(st, 24, 1, fps);

80 st->duration = frames;

81 }

83 return 0;

84 }

86 static int vc1t_read_packet(AVFormatContext *s,

87 AVPacket *pkt)

88 {

89 AVIOContext *pb = s->pb;

90 int frame_size;

91 int keyframe = 0;

92 uint32_t pts;

94 if(avio_feof(pb))

95 return AVERROR(EIO);

97 frame_size = avio_rl24(pb);

98 if(avio_r8(pb) & 0x80)

99 keyframe = 1;

100 pts = avio_rl32(pb);

101 if(av_get_packet(pb, pkt, frame_size) < 0)

102 return AVERROR(EIO);

103 if(s->streams[0]->time_base.den == 1000)

104 pkt->pts = pts;

105 pkt->flags |= keyframe ? AV_PKT_FLAG_KEY : 0;

106 pkt->pos -= 8;

107

108 return pkt->size;

109 }

110

111 AVInputFormat ff_vc1t_demuxer = {

112 .name = "vc1test",

113 .long_name = NULL_IF_CONFIG_SMALL("VC-1 test bitstream"),

114 .read_probe = vc1t_probe,

115 .read_header = vc1t_read_header,

116 .read_packet = vc1t_read_packet,

117 .flags = AVFMT_GENERIC_INDEX,

118 };

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