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tta.c
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1 /*
2  * TTA demuxer
3  * Copyright (c) 2006 Alex Beregszaszi
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  */
21 
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"
30 
31 typedef struct {
32  int totalframes, currentframe;
35 } TTAContext;
36 
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 }
42 
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 }
53 
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;
61 
62  ff_id3v1_read(s);
63 
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;
68 
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  }
77 
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  }
83 
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  }
89 
90  c->frame_size = samplerate * 256 / 245;
91  c->last_frame_size = nb_samples % c->frame_size;
92  if (!c->last_frame_size)
94  c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
95  c->currentframe = 0;
96 
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  st->codec->extradata_size = avio_tell(s->pb) - start_offset;
114  if (!st->codec->extradata) {
115  st->codec->extradata_size = 0;
116  return AVERROR(ENOMEM);
117  }
118 
119  avio_seek(s->pb, start_offset, SEEK_SET);
121 
122  ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
123  for (i = 0; i < c->totalframes; i++) {
124  uint32_t size = avio_rl32(s->pb);
125  av_add_index_entry(st, framepos, i * c->frame_size, size, 0,
127  framepos += size;
128  }
129  crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
130  if (crc != avio_rl32(s->pb)) {
131  av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
132  return AVERROR_INVALIDDATA;
133  }
134 
137  st->codec->channels = channels;
138  st->codec->sample_rate = samplerate;
140 
141  if (s->pb->seekable) {
142  int64_t pos = avio_tell(s->pb);
143  ff_ape_parse_tag(s);
144  avio_seek(s->pb, pos, SEEK_SET);
145  }
146 
147  return 0;
148 }
149 
151 {
152  TTAContext *c = s->priv_data;
153  AVStream *st = s->streams[0];
154  int size, ret;
155 
156  // FIXME!
157  if (c->currentframe >= c->totalframes)
158  return AVERROR_EOF;
159 
160  size = st->index_entries[c->currentframe].size;
161 
162  ret = av_get_packet(s->pb, pkt, size);
163  pkt->dts = st->index_entries[c->currentframe++].timestamp;
164  pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
165  c->frame_size;
166  return ret;
167 }
168 
169 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
170 {
171  TTAContext *c = s->priv_data;
172  AVStream *st = s->streams[stream_index];
173  int index = av_index_search_timestamp(st, timestamp, flags);
174  if (index < 0)
175  return -1;
176  if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
177  return -1;
178 
179  c->currentframe = index;
180 
181  return 0;
182 }
183 
185  .name = "tta",
186  .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
187  .priv_data_size = sizeof(TTAContext),
192  .extensions = "tta",
193 };