libavformat/tta.c

   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/bitstream.h"
  23 #include "avformat.h"
  24
  25 typedef struct {
  26     int totalframes, currentframe;
  27 } TTAContext;
  28
  29 static int tta_probe(AVProbeData *p)
  30 {
  31     const uint8_t *d = p->buf;
  32     if (d[0] == 'T' && d[1] == 'T' && d[2] == 'A' && d[3] == '1')
  33         return 80;
  34     return 0;
  35 }
  36
  37 static int tta_read_header(AVFormatContext *s, AVFormatParameters *ap)
  38 {
  39     TTAContext *c = s->priv_data;
  40     AVStream *st;
  41     int i, channels, bps, samplerate, datalen, framelen;
  42     uint64_t framepos;
  43
  44     if (get_le32(s->pb) != ff_get_fourcc("TTA1"))
  45         return -1; // not tta file
  46
  47     url_fskip(s->pb, 2); // FIXME: flags
  48     channels = get_le16(s->pb);
  49     bps = get_le16(s->pb);
  50     samplerate = get_le32(s->pb);
  51     if(samplerate <= 0 || samplerate > 1000000){
  52         av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
  53         return -1;
  54     }
  55
  56     datalen = get_le32(s->pb);
  57     if(datalen < 0){
  58         av_log(s, AV_LOG_ERROR, "nonsense datalen\n");
  59         return -1;
  60     }
  61
  62     url_fskip(s->pb, 4); // header crc
  63
  64     framelen = samplerate*256/245;
  65     c->totalframes = datalen / framelen + ((datalen % framelen) ? 1 : 0);
  66     c->currentframe = 0;
  67
  68     if(c->totalframes >= UINT_MAX/sizeof(uint32_t)){
  69         av_log(s, AV_LOG_ERROR, "totalframes too large\n");
  70         return -1;
  71     }
  72
  73     st = av_new_stream(s, 0);
  74     if (!st)
  75         return AVERROR(ENOMEM);
  76
  77     av_set_pts_info(st, 64, 1, samplerate);
  78     st->start_time = 0;
  79     st->duration = datalen;
  80
  81     framepos = url_ftell(s->pb) + 4*c->totalframes + 4;
  82
  83     for (i = 0; i < c->totalframes; i++) {
  84         uint32_t size = get_le32(s->pb);
  85         av_add_index_entry(st, framepos, i*framelen, size, 0, AVINDEX_KEYFRAME);
  86         framepos += size;
  87     }
  88     url_fskip(s->pb, 4); // seektable crc
  89
  90     st->codec->codec_type = CODEC_TYPE_AUDIO;
  91     st->codec->codec_id = CODEC_ID_TTA;
  92     st->codec->channels = channels;
  93     st->codec->sample_rate = samplerate;
  94     st->codec->bits_per_sample = bps;
  95
  96     st->codec->extradata_size = url_ftell(s->pb);
  97     if(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)st->codec->extradata_size){
  98         //this check is redundant as get_buffer should fail
  99         av_log(s, AV_LOG_ERROR, "extradata_size too large\n");
 100         return -1;
 101     }
 102     st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
 103     url_fseek(s->pb, 0, SEEK_SET);
 104     get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size);
 105
 106     return 0;
 107 }
 108
 109 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
 110 {
 111     TTAContext *c = s->priv_data;
 112     AVStream *st = s->streams[0];
 113     int size, ret;
 114
 115     // FIXME!
 116     if (c->currentframe > c->totalframes)
 117         return -1;
 118
 119     size = st->index_entries[c->currentframe].size;
 120
 121     ret = av_get_packet(s->pb, pkt, size);
 122     pkt->dts = st->index_entries[c->currentframe++].timestamp;
 123     return ret;
 124 }
 125
 126 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 127 {
 128     TTAContext *c = s->priv_data;
 129     AVStream *st = s->streams[stream_index];
 130     int index = av_index_search_timestamp(st, timestamp, flags);
 131     if (index < 0)
 132         return -1;
 133
 134     c->currentframe = index;
 135     url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
 136
 137     return 0;
 138 }
 139
 140 AVInputFormat tta_demuxer = {
 141     "tta",
 142     "true-audio",
 143     sizeof(TTAContext),
 144     tta_probe,
 145     tta_read_header,
 146     tta_read_packet,
 147     NULL,
 148     tta_read_seek,
 149     .extensions = "tta",
 150 };