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 unsigned long tta_check_crc(unsigned long checksum, const uint8_t *buf,
41 return av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), checksum, buf, len);
44 static int tta_probe(AVProbeData *p)
46 if (AV_RL32(&p->buf[0]) == MKTAG('T', 'T', 'A', '1') &&
47 (AV_RL16(&p->buf[4]) == 1 || AV_RL16(&p->buf[4]) == 2) &&
48 AV_RL16(&p->buf[6]) > 0 &&
49 AV_RL16(&p->buf[8]) > 0 &&
50 AV_RL32(&p->buf[10]) > 0)
51 return AVPROBE_SCORE_EXTENSION + 30;
55 static int tta_read_header(AVFormatContext *s)
57 TTAContext *c = s->priv_data;
59 int i, channels, bps, samplerate;
60 int64_t framepos, start_offset;
61 uint32_t nb_samples, crc;
65 start_offset = avio_tell(s->pb);
68 ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
69 if (avio_rl32(s->pb) != AV_RL32("TTA1"))
70 return AVERROR_INVALIDDATA;
72 avio_skip(s->pb, 2); // FIXME: flags
73 channels = avio_rl16(s->pb);
74 bps = avio_rl16(s->pb);
75 samplerate = avio_rl32(s->pb);
76 if(samplerate <= 0 || samplerate > 1000000){
77 av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
78 return AVERROR_INVALIDDATA;
81 nb_samples = avio_rl32(s->pb);
83 av_log(s, AV_LOG_ERROR, "invalid number of samples\n");
84 return AVERROR_INVALIDDATA;
87 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
88 if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {
89 av_log(s, AV_LOG_ERROR, "Header CRC error\n");
90 return AVERROR_INVALIDDATA;
93 c->frame_size = samplerate * 256 / 245;
94 c->last_frame_size = nb_samples % c->frame_size;
95 if (!c->last_frame_size)
96 c->last_frame_size = c->frame_size;
97 c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
100 if(c->totalframes >= UINT_MAX/sizeof(uint32_t) || c->totalframes <= 0){
101 av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);
102 return AVERROR_INVALIDDATA;
105 st = avformat_new_stream(s, NULL);
107 return AVERROR(ENOMEM);
109 avpriv_set_pts_info(st, 64, 1, samplerate);
111 st->duration = nb_samples;
113 framepos = avio_tell(s->pb);
116 framepos += 4 * c->totalframes + 4;
118 if (ff_alloc_extradata(st->codecpar, avio_tell(s->pb) - start_offset))
119 return AVERROR(ENOMEM);
121 avio_seek(s->pb, start_offset, SEEK_SET);
122 avio_read(s->pb, st->codecpar->extradata, st->codecpar->extradata_size);
124 ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
125 for (i = 0; i < c->totalframes; i++) {
126 uint32_t size = avio_rl32(s->pb);
128 if ((r = av_add_index_entry(st, framepos, i * c->frame_size, size, 0,
129 AVINDEX_KEYFRAME)) < 0)
133 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
134 if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {
135 av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
136 return AVERROR_INVALIDDATA;
139 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
140 st->codecpar->codec_id = AV_CODEC_ID_TTA;
141 st->codecpar->channels = channels;
142 st->codecpar->sample_rate = samplerate;
143 st->codecpar->bits_per_coded_sample = bps;
145 if (s->pb->seekable) {
146 int64_t pos = avio_tell(s->pb);
148 avio_seek(s->pb, pos, SEEK_SET);
154 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
156 TTAContext *c = s->priv_data;
157 AVStream *st = s->streams[0];
161 if (c->currentframe >= c->totalframes)
164 if (st->nb_index_entries < c->totalframes) {
165 av_log(s, AV_LOG_ERROR, "Index entry disappeared\n");
166 return AVERROR_INVALIDDATA;
169 size = st->index_entries[c->currentframe].size;
171 ret = av_get_packet(s->pb, pkt, size);
172 pkt->dts = st->index_entries[c->currentframe++].timestamp;
173 pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
178 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
180 TTAContext *c = s->priv_data;
181 AVStream *st = s->streams[stream_index];
182 int index = av_index_search_timestamp(st, timestamp, flags);
185 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
188 c->currentframe = index;
193 AVInputFormat ff_tta_demuxer = {
195 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
196 .priv_data_size = sizeof(TTAContext),
197 .read_probe = tta_probe,
198 .read_header = tta_read_header,
199 .read_packet = tta_read_packet,
200 .read_seek = tta_read_seek,