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00020
00021 #include "avformat.h"
00022 #include "bitstream.h"
00023
00024 typedef struct {
00025 int totalframes, currentframe;
00026 } TTAContext;
00027
00028 static int tta_probe(AVProbeData *p)
00029 {
00030 const uint8_t *d = p->buf;
00031 if (d[0] == 'T' && d[1] == 'T' && d[2] == 'A' && d[3] == '1')
00032 return 80;
00033 return 0;
00034 }
00035
00036 static int tta_read_header(AVFormatContext *s, AVFormatParameters *ap)
00037 {
00038 TTAContext *c = s->priv_data;
00039 AVStream *st;
00040 int i, channels, bps, samplerate, datalen, framelen;
00041 uint64_t framepos;
00042
00043 if (get_le32(s->pb) != ff_get_fourcc("TTA1"))
00044 return -1;
00045
00046 url_fskip(s->pb, 2);
00047 channels = get_le16(s->pb);
00048 bps = get_le16(s->pb);
00049 samplerate = get_le32(s->pb);
00050 if(samplerate <= 0 || samplerate > 1000000){
00051 av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
00052 return -1;
00053 }
00054
00055 datalen = get_le32(s->pb);
00056 if(datalen < 0){
00057 av_log(s, AV_LOG_ERROR, "nonsense datalen\n");
00058 return -1;
00059 }
00060
00061 url_fskip(s->pb, 4);
00062
00063 framelen = samplerate*256/245;
00064 c->totalframes = datalen / framelen + ((datalen % framelen) ? 1 : 0);
00065 c->currentframe = 0;
00066
00067 if(c->totalframes >= UINT_MAX/sizeof(uint32_t)){
00068 av_log(s, AV_LOG_ERROR, "totalframes too large\n");
00069 return -1;
00070 }
00071
00072 st = av_new_stream(s, 0);
00073 if (!st)
00074 return AVERROR(ENOMEM);
00075
00076 av_set_pts_info(st, 64, 1, samplerate);
00077 st->start_time = 0;
00078 st->duration = datalen;
00079
00080 framepos = url_ftell(s->pb) + 4*c->totalframes + 4;
00081
00082 for (i = 0; i < c->totalframes; i++) {
00083 uint32_t size = get_le32(s->pb);
00084 av_add_index_entry(st, framepos, i*framelen, size, 0, AVINDEX_KEYFRAME);
00085 framepos += size;
00086 }
00087 url_fskip(s->pb, 4);
00088
00089 st->codec->codec_type = CODEC_TYPE_AUDIO;
00090 st->codec->codec_id = CODEC_ID_TTA;
00091 st->codec->channels = channels;
00092 st->codec->sample_rate = samplerate;
00093 st->codec->bits_per_sample = bps;
00094
00095 st->codec->extradata_size = url_ftell(s->pb);
00096 if(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)st->codec->extradata_size){
00097
00098 av_log(s, AV_LOG_ERROR, "extradata_size too large\n");
00099 return -1;
00100 }
00101 st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
00102 url_fseek(s->pb, 0, SEEK_SET);
00103 get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size);
00104
00105 return 0;
00106 }
00107
00108 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
00109 {
00110 TTAContext *c = s->priv_data;
00111 AVStream *st = s->streams[0];
00112 int size, ret;
00113
00114
00115 if (c->currentframe > c->totalframes)
00116 return -1;
00117
00118 size = st->index_entries[c->currentframe].size;
00119
00120 ret = av_get_packet(s->pb, pkt, size);
00121 pkt->dts = st->index_entries[c->currentframe++].timestamp;
00122 return ret;
00123 }
00124
00125 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00126 {
00127 TTAContext *c = s->priv_data;
00128 AVStream *st = s->streams[stream_index];
00129 int index = av_index_search_timestamp(st, timestamp, flags);
00130 if (index < 0)
00131 return -1;
00132
00133 c->currentframe = index;
00134 url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
00135
00136 return 0;
00137 }
00138
00139 AVInputFormat tta_demuxer = {
00140 "tta",
00141 "true-audio",
00142 sizeof(TTAContext),
00143 tta_probe,
00144 tta_read_header,
00145 tta_read_packet,
00146 NULL,
00147 tta_read_seek,
00148 .extensions = "tta",
00149 };