FFmpeg: libavformat/tta.c Source File

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libavformat

tta.c

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1 /*

2 * TTA 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 "libavcodec/get_bits.h"

23 #include "apetag.h"

24 #include "avformat.h"

25 #include "avio_internal.h"

26 #include "internal.h"

27 #include "id3v1.h"

28 #include "libavutil/crc.h"

29 #include "libavutil/dict.h"

31 typedef struct {

32 int totalframes, currentframe;

33 int frame_size;

34 int last_frame_size;

35 } TTAContext;

37 static unsigned long tta_check_crc(unsigned long checksum, const uint8_t *buf,

38 unsigned int len)

39 {

40 return av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), checksum, buf, len);

41 }

43 static int tta_probe(AVProbeData *p)

44 {

45 if (AV_RL32(&p->buf[0]) == MKTAG('T', 'T', 'A', '1') &&

46 (AV_RL16(&p->buf[4]) == 1 || AV_RL16(&p->buf[4]) == 2) &&

47 AV_RL16(&p->buf[6]) > 0 &&

48 AV_RL16(&p->buf[8]) > 0 &&

49 AV_RL32(&p->buf[10]) > 0)

50 return AVPROBE_SCORE_EXTENSION + 30;

51 return 0;

52 }

54 static int tta_read_header(AVFormatContext *s)

55 {

56 TTAContext *c = s->priv_data;

57 AVStream *st;

58 int i, channels, bps, samplerate;

59 uint64_t framepos, start_offset;

60 uint32_t nb_samples, crc;

62 ff_id3v1_read(s);

64 start_offset = avio_tell(s->pb);

65 ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);

66 if (avio_rl32(s->pb) != AV_RL32("TTA1"))

67 return AVERROR_INVALIDDATA;

69 avio_skip(s->pb, 2); // FIXME: flags

70 channels = avio_rl16(s->pb);

71 bps = avio_rl16(s->pb);

72 samplerate = avio_rl32(s->pb);

73 if(samplerate <= 0 || samplerate > 1000000){

74 av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");

75 return AVERROR_INVALIDDATA;

76 }

78 nb_samples = avio_rl32(s->pb);

79 if (!nb_samples) {

80 av_log(s, AV_LOG_ERROR, "invalid number of samples\n");

81 return AVERROR_INVALIDDATA;

82 }

84 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;

85 if (crc != avio_rl32(s->pb)) {

86 av_log(s, AV_LOG_ERROR, "Header CRC error\n");

87 return AVERROR_INVALIDDATA;

88 }

90 c->frame_size = samplerate * 256 / 245;

91 c->last_frame_size = nb_samples % c->frame_size;

92 if (!c->last_frame_size)

93 c->last_frame_size = c->frame_size;

94 c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);

95 c->currentframe = 0;

97 if(c->totalframes >= UINT_MAX/sizeof(uint32_t) || c->totalframes <= 0){

98 av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);

99 return AVERROR_INVALIDDATA;

100 }

101

102 st = avformat_new_stream(s, NULL);

103 if (!st)

104 return AVERROR(ENOMEM);

105

106 avpriv_set_pts_info(st, 64, 1, samplerate);

107 st->start_time = 0;

108 st->duration = nb_samples;

109

110 framepos = avio_tell(s->pb) + 4*c->totalframes + 4;

111

112 if (ff_alloc_extradata(st->codec, avio_tell(s->pb) - start_offset))

113 return AVERROR(ENOMEM);

114

115 avio_seek(s->pb, start_offset, SEEK_SET);

116 avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);

117

118 ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);

119 for (i = 0; i < c->totalframes; i++) {

120 uint32_t size = avio_rl32(s->pb);

121 av_add_index_entry(st, framepos, i * c->frame_size, size, 0,

122 AVINDEX_KEYFRAME);

123 framepos += size;

124 }

125 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;

126 if (crc != avio_rl32(s->pb)) {

127 av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");

128 return AVERROR_INVALIDDATA;

129 }

130

131 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

132 st->codec->codec_id = AV_CODEC_ID_TTA;

133 st->codec->channels = channels;

134 st->codec->sample_rate = samplerate;

135 st->codec->bits_per_coded_sample = bps;

136

137 if (s->pb->seekable) {

138 int64_t pos = avio_tell(s->pb);

139 ff_ape_parse_tag(s);

140 avio_seek(s->pb, pos, SEEK_SET);

141 }

142

143 return 0;

144 }

145

146 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)

147 {

148 TTAContext *c = s->priv_data;

149 AVStream *st = s->streams[0];

150 int size, ret;

151

152 // FIXME!

153 if (c->currentframe >= c->totalframes)

154 return AVERROR_EOF;

155

156 size = st->index_entries[c->currentframe].size;

157

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

159 pkt->dts = st->index_entries[c->currentframe++].timestamp;

160 pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :

161 c->frame_size;

162 return ret;

163 }

164

165 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

166 {

167 TTAContext *c = s->priv_data;

168 AVStream *st = s->streams[stream_index];

169 int index = av_index_search_timestamp(st, timestamp, flags);

170 if (index < 0)

171 return -1;

172 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)

173 return -1;

174

175 c->currentframe = index;

176

177 return 0;

178 }

179

180 AVInputFormat ff_tta_demuxer = {

181 .name = "tta",

182 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),

183 .priv_data_size = sizeof(TTAContext),

184 .read_probe = tta_probe,

185 .read_header = tta_read_header,

186 .read_packet = tta_read_packet,

187 .read_seek = tta_read_seek,

188 .extensions = "tta",

189 };

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