FFmpeg: libavformat/lvfdec.c Source File

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libavformat

lvfdec.c

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1 /*

2 * LVF 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/intreadwrite.h"

23 #include "avformat.h"

24 #include "riff.h"

26 static int lvf_probe(AVProbeData *p)

27 {

28 if (AV_RL32(p->buf) == MKTAG('L', 'V', 'F', 'F'))

29 return AVPROBE_SCORE_EXTENSION;

30 return 0;

31 }

33 static int lvf_read_header(AVFormatContext *s)

34 {

35 AVStream *st;

36 int64_t next_offset;

37 unsigned size, nb_streams, id;

39 avio_skip(s->pb, 16);

40 nb_streams = avio_rl32(s->pb);

41 if (!nb_streams)

42 return AVERROR_INVALIDDATA;

43 if (nb_streams > 2) {

44 avpriv_request_sample(s, "%d streams", nb_streams);

45 return AVERROR_PATCHWELCOME;

46 }

48 avio_skip(s->pb, 1012);

50 while (!url_feof(s->pb)) {

51 id = avio_rl32(s->pb);

52 size = avio_rl32(s->pb);

53 next_offset = avio_tell(s->pb) + size;

55 switch (id) {

56 case MKTAG('0', '0', 'f', 'm'):

57 st = avformat_new_stream(s, 0);

58 if (!st)

59 return AVERROR(ENOMEM);

61 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

62 avio_skip(s->pb, 4);

63 st->codec->width = avio_rl32(s->pb);

64 st->codec->height = avio_rl32(s->pb);

65 avio_skip(s->pb, 4);

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

67 st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags,

68 st->codec->codec_tag);

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

70 break;

71 case MKTAG('0', '1', 'f', 'm'):

72 st = avformat_new_stream(s, 0);

73 if (!st)

74 return AVERROR(ENOMEM);

76 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

77 st->codec->codec_tag = avio_rl16(s->pb);

78 st->codec->channels = avio_rl16(s->pb);

79 st->codec->sample_rate = avio_rl16(s->pb);

80 avio_skip(s->pb, 8);

81 st->codec->bits_per_coded_sample = avio_r8(s->pb);

82 st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags,

83 st->codec->codec_tag);

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

85 break;

86 case 0:

87 avio_seek(s->pb, 2048 + 8, SEEK_SET);

88 return 0;

89 default:

90 avpriv_request_sample(s, "id %d", id);

91 return AVERROR_PATCHWELCOME;

92 }

94 avio_seek(s->pb, next_offset, SEEK_SET);

95 }

97 return AVERROR_EOF;

98 }

100 static int lvf_read_packet(AVFormatContext *s, AVPacket *pkt)

101 {

102 unsigned size, flags, timestamp, id;

103 int64_t pos;

104 int ret, is_video = 0;

105

106 pos = avio_tell(s->pb);

107 while (!url_feof(s->pb)) {

108 id = avio_rl32(s->pb);

109 size = avio_rl32(s->pb);

110

111 if (size == 0xFFFFFFFFu)

112 return AVERROR_EOF;

113

114 switch (id) {

115 case MKTAG('0', '0', 'd', 'c'):

116 is_video = 1;

117 case MKTAG('0', '1', 'w', 'b'):

118 if (size < 8)

119 return AVERROR_INVALIDDATA;

120 timestamp = avio_rl32(s->pb);

121 flags = avio_rl32(s->pb);

122 ret = av_get_packet(s->pb, pkt, size - 8);

123 if (flags & (1 << 12))

124 pkt->flags |= AV_PKT_FLAG_KEY;

125 pkt->stream_index = is_video ? 0 : 1;

126 pkt->pts = timestamp;

127 pkt->pos = pos;

128 return ret;

129 default:

130 ret = avio_skip(s->pb, size);

131 }

132

133 if (ret < 0)

134 return ret;

135 }

136

137 return AVERROR_EOF;

138 }

139

140 AVInputFormat ff_lvf_demuxer = {

141 .name = "lvf",

142 .long_name = NULL_IF_CONFIG_SMALL("LVF"),

143 .read_probe = lvf_probe,

144 .read_header = lvf_read_header,

145 .read_packet = lvf_read_packet,

146 .extensions = "lvf",

147 .flags = AVFMT_GENERIC_INDEX,

148 };

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