tta.c
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1 /*
2  * TTA demuxer
3  * Copyright (c) 2006 Alex Beregszaszi
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavcodec/get_bits.h"
23 #include "avformat.h"
24 #include "internal.h"
25 #include "id3v1.h"
26 #include "libavutil/dict.h"
27 
28 typedef struct {
29  int totalframes, currentframe;
30 } TTAContext;
31 
32 static int tta_probe(AVProbeData *p)
33 {
34  const uint8_t *d = p->buf;
35 
36  if (d[0] == 'T' && d[1] == 'T' && d[2] == 'A' && d[3] == '1')
37  return 80;
38  return 0;
39 }
40 
42 {
43  TTAContext *c = s->priv_data;
44  AVStream *st;
45  int i, channels, bps, samplerate, datalen, framelen;
46  uint64_t framepos, start_offset;
47 
49  ff_id3v1_read(s);
50 
51  start_offset = avio_tell(s->pb);
52  if (avio_rl32(s->pb) != AV_RL32("TTA1"))
53  return -1; // not tta file
54 
55  avio_skip(s->pb, 2); // FIXME: flags
56  channels = avio_rl16(s->pb);
57  bps = avio_rl16(s->pb);
58  samplerate = avio_rl32(s->pb);
59  if(samplerate <= 0 || samplerate > 1000000){
60  av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
61  return -1;
62  }
63 
64  datalen = avio_rl32(s->pb);
65  if(datalen < 0){
66  av_log(s, AV_LOG_ERROR, "nonsense datalen\n");
67  return -1;
68  }
69 
70  avio_skip(s->pb, 4); // header crc
71 
72  framelen = samplerate*256/245;
73  c->totalframes = datalen / framelen + ((datalen % framelen) ? 1 : 0);
74  c->currentframe = 0;
75 
76  if(c->totalframes >= UINT_MAX/sizeof(uint32_t)){
77  av_log(s, AV_LOG_ERROR, "totalframes too large\n");
78  return -1;
79  }
80 
81  st = avformat_new_stream(s, NULL);
82  if (!st)
83  return AVERROR(ENOMEM);
84 
85  avpriv_set_pts_info(st, 64, 1, samplerate);
86  st->start_time = 0;
87  st->duration = datalen;
88 
89  framepos = avio_tell(s->pb) + 4*c->totalframes + 4;
90 
91  for (i = 0; i < c->totalframes; i++) {
92  uint32_t size = avio_rl32(s->pb);
93  av_add_index_entry(st, framepos, i*framelen, size, 0, AVINDEX_KEYFRAME);
94  framepos += size;
95  }
96  avio_skip(s->pb, 4); // seektable crc
97 
100  st->codec->channels = channels;
101  st->codec->sample_rate = samplerate;
103 
104  st->codec->extradata_size = avio_tell(s->pb) - start_offset;
106  //this check is redundant as avio_read should fail
107  av_log(s, AV_LOG_ERROR, "extradata_size too large\n");
108  return -1;
109  }
111  if (!st->codec->extradata) {
112  st->codec->extradata_size = 0;
113  return AVERROR(ENOMEM);
114  }
115  avio_seek(s->pb, start_offset, SEEK_SET);
117 
118  return 0;
119 }
120 
122 {
123  TTAContext *c = s->priv_data;
124  AVStream *st = s->streams[0];
125  int size, ret;
126 
127  // FIXME!
128  if (c->currentframe >= c->totalframes)
129  return AVERROR_EOF;
130 
131  size = st->index_entries[c->currentframe].size;
132 
133  ret = av_get_packet(s->pb, pkt, size);
134  pkt->dts = st->index_entries[c->currentframe++].timestamp;
135  return ret;
136 }
137 
138 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
139 {
140  TTAContext *c = s->priv_data;
141  AVStream *st = s->streams[stream_index];
142  int index = av_index_search_timestamp(st, timestamp, flags);
143  if (index < 0)
144  return -1;
145 
146  c->currentframe = index;
147  avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET);
148 
149  return 0;
150 }
151 
153  .name = "tta",
154  .long_name = NULL_IF_CONFIG_SMALL("True Audio"),
155  .priv_data_size = sizeof(TTAContext),
160  .extensions = "tta",
161 };