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 "libavcodec/get_bits.h"
25 #include "avio_internal.h"
28 #include "libavutil/crc.h"
29 #include "libavutil/dict.h"
32 int totalframes, currentframe;
37 static unsigned long tta_check_crc(unsigned long checksum, const uint8_t *buf,
40 return av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), checksum, buf, len);
43 static int tta_probe(AVProbeData *p)
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;
54 static int tta_read_header(AVFormatContext *s)
56 TTAContext *c = s->priv_data;
58 int i, channels, bps, samplerate;
59 uint64_t framepos, start_offset;
60 uint32_t nb_samples, crc;
63 if (s->pb->seekable) {
64 int64_t pos = avio_tell(s->pb);
66 avio_seek(s->pb, pos, SEEK_SET);
69 start_offset = avio_tell(s->pb);
70 ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
71 if (avio_rl32(s->pb) != AV_RL32("TTA1"))
72 return AVERROR_INVALIDDATA;
74 avio_skip(s->pb, 2); // FIXME: flags
75 channels = avio_rl16(s->pb);
76 bps = avio_rl16(s->pb);
77 samplerate = avio_rl32(s->pb);
78 if(samplerate <= 0 || samplerate > 1000000){
79 av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
80 return AVERROR_INVALIDDATA;
83 nb_samples = avio_rl32(s->pb);
85 av_log(s, AV_LOG_ERROR, "invalid number of samples\n");
86 return AVERROR_INVALIDDATA;
89 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
90 if (crc != avio_rl32(s->pb)) {
91 av_log(s, AV_LOG_ERROR, "Header CRC error\n");
92 return AVERROR_INVALIDDATA;
95 c->frame_size = samplerate * 256 / 245;
96 c->last_frame_size = nb_samples % c->frame_size;
97 if (!c->last_frame_size)
98 c->last_frame_size = c->frame_size;
99 c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
102 if(c->totalframes >= UINT_MAX/sizeof(uint32_t) || c->totalframes <= 0){
103 av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);
104 return AVERROR_INVALIDDATA;
107 st = avformat_new_stream(s, NULL);
109 return AVERROR(ENOMEM);
111 avpriv_set_pts_info(st, 64, 1, samplerate);
113 st->duration = nb_samples;
115 framepos = avio_tell(s->pb) + 4*c->totalframes + 4;
117 st->codec->extradata_size = avio_tell(s->pb) - start_offset;
118 st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
119 if (!st->codec->extradata) {
120 st->codec->extradata_size = 0;
121 return AVERROR(ENOMEM);
124 avio_seek(s->pb, start_offset, SEEK_SET);
125 avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
127 ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);
128 for (i = 0; i < c->totalframes; i++) {
129 uint32_t size = avio_rl32(s->pb);
130 av_add_index_entry(st, framepos, i * c->frame_size, size, 0,
134 crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
135 if (crc != avio_rl32(s->pb)) {
136 av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
137 return AVERROR_INVALIDDATA;
140 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
141 st->codec->codec_id = AV_CODEC_ID_TTA;
142 st->codec->channels = channels;
143 st->codec->sample_rate = samplerate;
144 st->codec->bits_per_coded_sample = bps;
149 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
151 TTAContext *c = s->priv_data;
152 AVStream *st = s->streams[0];
156 if (c->currentframe >= c->totalframes)
159 size = st->index_entries[c->currentframe].size;
161 ret = av_get_packet(s->pb, pkt, size);
162 pkt->dts = st->index_entries[c->currentframe++].timestamp;
163 pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
168 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
170 TTAContext *c = s->priv_data;
171 AVStream *st = s->streams[stream_index];
172 int index = av_index_search_timestamp(st, timestamp, flags);
175 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
178 c->currentframe = index;
183 AVInputFormat ff_tta_demuxer = {
185 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
186 .priv_data_size = sizeof(TTAContext),
187 .read_probe = tta_probe,
188 .read_header = tta_read_header,
189 .read_packet = tta_read_packet,
190 .read_seek = tta_read_seek,