3 * Copyright (c) 2006 Alex Beregszaszi
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/crc.h"
23 #include "libavutil/dict.h"
24 #include "libavutil/intreadwrite.h"
28 #include "avio_internal.h"
32 typedef struct TTAContext {
33 int totalframes, currentframe;
38 static int tta_probe(AVProbeData *p)
40 if (AV_RL32(&p->buf[0]) == MKTAG('T', 'T', 'A', '1') &&
41 (AV_RL16(&p->buf[4]) == 1 || AV_RL16(&p->buf[4]) == 2) &&
42 AV_RL16(&p->buf[6]) > 0 &&
43 AV_RL16(&p->buf[8]) > 0 &&
44 AV_RL32(&p->buf[10]) > 0)
45 return AVPROBE_SCORE_EXTENSION + 30;
49 static int tta_read_header(AVFormatContext *s)
51 TTAContext *c = s->priv_data;
53 int i, channels, bps, samplerate;
54 int64_t framepos, start_offset;
55 uint32_t nb_samples, crc;
59 start_offset = avio_tell(s->pb);
62 ffio_init_checksum(s->pb, ff_crcEDB88320_update, UINT32_MAX);
63 if (avio_rl32(s->pb) != AV_RL32("TTA1"))
64 return AVERROR_INVALIDDATA;
66 avio_skip(s->pb, 2); // FIXME: flags
67 channels = avio_rl16(s->pb);
68 bps = avio_rl16(s->pb);
69 samplerate = avio_rl32(s->pb);
70 if(samplerate <= 0 || samplerate > 1000000){
71 av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
72 return AVERROR_INVALIDDATA;
75 nb_samples = avio_rl32(s->pb);
77 av_log(s, AV_LOG_ERROR, "invalid number of samples\n");
78 return AVERROR_INVALIDDATA;
81 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
82 if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {
83 av_log(s, AV_LOG_ERROR, "Header CRC error\n");
84 return AVERROR_INVALIDDATA;
87 c->frame_size = samplerate * 256 / 245;
88 c->last_frame_size = nb_samples % c->frame_size;
89 if (!c->last_frame_size)
90 c->last_frame_size = c->frame_size;
91 c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
94 if(c->totalframes >= UINT_MAX/sizeof(uint32_t) || c->totalframes <= 0){
95 av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);
96 return AVERROR_INVALIDDATA;
99 st = avformat_new_stream(s, NULL);
101 return AVERROR(ENOMEM);
103 avpriv_set_pts_info(st, 64, 1, samplerate);
105 st->duration = nb_samples;
107 framepos = avio_tell(s->pb);
110 framepos += 4 * c->totalframes + 4;
112 if (ff_alloc_extradata(st->codecpar, avio_tell(s->pb) - start_offset))
113 return AVERROR(ENOMEM);
115 avio_seek(s->pb, start_offset, SEEK_SET);
116 avio_read(s->pb, st->codecpar->extradata, st->codecpar->extradata_size);
118 ffio_init_checksum(s->pb, ff_crcEDB88320_update, UINT32_MAX);
119 for (i = 0; i < c->totalframes; i++) {
120 uint32_t size = avio_rl32(s->pb);
122 if ((r = av_add_index_entry(st, framepos, i * c->frame_size, size, 0,
123 AVINDEX_KEYFRAME)) < 0)
127 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
128 if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {
129 av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
130 return AVERROR_INVALIDDATA;
133 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
134 st->codecpar->codec_id = AV_CODEC_ID_TTA;
135 st->codecpar->channels = channels;
136 st->codecpar->sample_rate = samplerate;
137 st->codecpar->bits_per_coded_sample = bps;
139 if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
140 int64_t pos = avio_tell(s->pb);
142 avio_seek(s->pb, pos, SEEK_SET);
148 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
150 TTAContext *c = s->priv_data;
151 AVStream *st = s->streams[0];
155 if (c->currentframe >= c->totalframes)
158 if (st->nb_index_entries < c->totalframes) {
159 av_log(s, AV_LOG_ERROR, "Index entry disappeared\n");
160 return AVERROR_INVALIDDATA;
163 size = st->index_entries[c->currentframe].size;
165 ret = av_get_packet(s->pb, pkt, size);
166 pkt->dts = st->index_entries[c->currentframe++].timestamp;
167 pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
172 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
174 TTAContext *c = s->priv_data;
175 AVStream *st = s->streams[stream_index];
176 int index = av_index_search_timestamp(st, timestamp, flags);
179 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
182 c->currentframe = index;
187 AVInputFormat ff_tta_demuxer = {
189 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
190 .priv_data_size = sizeof(TTAContext),
191 .read_probe = tta_probe,
192 .read_header = tta_read_header,
193 .read_packet = tta_read_packet,
194 .read_seek = tta_read_seek,