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;
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;
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;
78 nb_samples = avio_rl32(s->pb);
80 av_log(s, AV_LOG_ERROR, "invalid number of samples\n");
81 return AVERROR_INVALIDDATA;
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;
90 c->frame_size = samplerate * 256 / 245;
91 c->last_frame_size = nb_samples % c->frame_size;
92 if (!c->last_frame_size)
93 c->last_frame_size = c->frame_size;
94 c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);
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;
102 st = avformat_new_stream(s, NULL);
104 return AVERROR(ENOMEM);
106 avpriv_set_pts_info(st, 64, 1, samplerate);
108 st->duration = nb_samples;
110 framepos = avio_tell(s->pb) + 4*c->totalframes + 4;
112 st->codec->extradata_size = avio_tell(s->pb) - start_offset;
113 st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
114 if (!st->codec->extradata) {
115 st->codec->extradata_size = 0;
116 return AVERROR(ENOMEM);
119 avio_seek(s->pb, start_offset, SEEK_SET);
120 avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
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,
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;
135 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
136 st->codec->codec_id = AV_CODEC_ID_TTA;
137 st->codec->channels = channels;
138 st->codec->sample_rate = samplerate;
139 st->codec->bits_per_coded_sample = bps;
141 if (s->pb->seekable) {
142 int64_t pos = avio_tell(s->pb);
144 avio_seek(s->pb, pos, SEEK_SET);
150 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
152 TTAContext *c = s->priv_data;
153 AVStream *st = s->streams[0];
157 if (c->currentframe >= c->totalframes)
160 size = st->index_entries[c->currentframe].size;
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 :
169 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
171 TTAContext *c = s->priv_data;
172 AVStream *st = s->streams[stream_index];
173 int index = av_index_search_timestamp(st, timestamp, flags);
176 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
179 c->currentframe = index;
184 AVInputFormat ff_tta_demuxer = {
186 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
187 .priv_data_size = sizeof(TTAContext),
188 .read_probe = tta_probe,
189 .read_header = tta_read_header,
190 .read_packet = tta_read_packet,
191 .read_seek = tta_read_seek,