FFmpeg: libavformat/dfa.c Source File

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libavformat

dfa.c

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1 /*

2 * Chronomaster DFA 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 #include <inttypes.h>

24 #include "libavutil/intreadwrite.h"

25 #include "avformat.h"

26 #include "internal.h"

28 static int dfa_probe(AVProbeData *p)

29 {

30 if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('D', 'F', 'I', 'A'))

31 return 0;

33 if (AV_RL32(p->buf + 16) != 0x80)

34 return AVPROBE_SCORE_MAX / 4;

36 return AVPROBE_SCORE_MAX;

37 }

39 static int dfa_read_header(AVFormatContext *s)

40 {

41 AVIOContext *pb = s->pb;

42 AVStream *st;

43 int frames;

44 int version;

45 uint32_t mspf;

47 if (avio_rl32(pb) != MKTAG('D', 'F', 'I', 'A')) {

48 av_log(s, AV_LOG_ERROR, "Invalid magic for DFA\n");

49 return AVERROR_INVALIDDATA;

50 }

52 version = avio_rl16(pb);

53 frames = avio_rl16(pb);

55 st = avformat_new_stream(s, NULL);

56 if (!st)

57 return AVERROR(ENOMEM);

59 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

60 st->codec->codec_id = AV_CODEC_ID_DFA;

61 st->codec->width = avio_rl16(pb);

62 st->codec->height = avio_rl16(pb);

63 mspf = avio_rl32(pb);

64 if (!mspf) {

65 av_log(s, AV_LOG_WARNING, "Zero FPS reported, defaulting to 10\n");

66 mspf = 100;

67 }

68 avpriv_set_pts_info(st, 24, mspf, 1000);

69 avio_skip(pb, 128 - 16); // padding

70 st->duration = frames;

72 if (ff_alloc_extradata(st->codec, 2))

73 return AVERROR(ENOMEM);

74 AV_WL16(st->codec->extradata, version);

75 if (version == 0x100)

76 st->sample_aspect_ratio = (AVRational){2, 1};

78 return 0;

79 }

81 static int dfa_read_packet(AVFormatContext *s, AVPacket *pkt)

82 {

83 AVIOContext *pb = s->pb;

84 uint32_t frame_size;

85 int ret, first = 1;

87 if (avio_feof(pb))

88 return AVERROR_EOF;

90 if (av_get_packet(pb, pkt, 12) != 12)

91 return AVERROR(EIO);

92 while (!avio_feof(pb)) {

93 if (!first) {

94 ret = av_append_packet(pb, pkt, 12);

95 if (ret < 0) {

96 av_free_packet(pkt);

97 return ret;

98 }

99 } else

100 first = 0;

101 frame_size = AV_RL32(pkt->data + pkt->size - 8);

102 if (frame_size > INT_MAX - 4) {

103 av_log(s, AV_LOG_ERROR, "Too large chunk size: %"PRIu32"\n", frame_size);

104 return AVERROR(EIO);

105 }

106 if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {

107 if (frame_size) {

108 av_log(s, AV_LOG_WARNING,

109 "skipping %"PRIu32" bytes of end-of-frame marker chunk\n",

110 frame_size);

111 avio_skip(pb, frame_size);

112 }

113 return 0;

114 }

115 ret = av_append_packet(pb, pkt, frame_size);

116 if (ret < 0) {

117 av_free_packet(pkt);

118 return ret;

119 }

120 }

121

122 return 0;

123 }

124

125 AVInputFormat ff_dfa_demuxer = {

126 .name = "dfa",

127 .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),

128 .read_probe = dfa_probe,

129 .read_header = dfa_read_header,

130 .read_packet = dfa_read_packet,

131 .flags = AVFMT_GENERIC_INDEX,

132 };

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