Libav
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00001 /* 00002 * TTA demuxer 00003 * Copyright (c) 2006 Alex Beregszaszi 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "libavcodec/get_bits.h" 00023 #include "avformat.h" 00024 #include "id3v2.h" 00025 #include "id3v1.h" 00026 00027 typedef struct { 00028 int totalframes, currentframe; 00029 } TTAContext; 00030 00031 static int tta_probe(AVProbeData *p) 00032 { 00033 const uint8_t *d = p->buf; 00034 00035 if (ff_id3v2_match(d)) 00036 d += ff_id3v2_tag_len(d); 00037 00038 if (d - p->buf >= p->buf_size) 00039 return 0; 00040 00041 if (d[0] == 'T' && d[1] == 'T' && d[2] == 'A' && d[3] == '1') 00042 return 80; 00043 return 0; 00044 } 00045 00046 static int tta_read_header(AVFormatContext *s, AVFormatParameters *ap) 00047 { 00048 TTAContext *c = s->priv_data; 00049 AVStream *st; 00050 int i, channels, bps, samplerate, datalen, framelen; 00051 uint64_t framepos, start_offset; 00052 00053 ff_id3v2_read(s); 00054 if (!av_metadata_get(s->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX)) 00055 ff_id3v1_read(s); 00056 00057 start_offset = url_ftell(s->pb); 00058 if (get_le32(s->pb) != AV_RL32("TTA1")) 00059 return -1; // not tta file 00060 00061 url_fskip(s->pb, 2); // FIXME: flags 00062 channels = get_le16(s->pb); 00063 bps = get_le16(s->pb); 00064 samplerate = get_le32(s->pb); 00065 if(samplerate <= 0 || samplerate > 1000000){ 00066 av_log(s, AV_LOG_ERROR, "nonsense samplerate\n"); 00067 return -1; 00068 } 00069 00070 datalen = get_le32(s->pb); 00071 if(datalen < 0){ 00072 av_log(s, AV_LOG_ERROR, "nonsense datalen\n"); 00073 return -1; 00074 } 00075 00076 url_fskip(s->pb, 4); // header crc 00077 00078 framelen = samplerate*256/245; 00079 c->totalframes = datalen / framelen + ((datalen % framelen) ? 1 : 0); 00080 c->currentframe = 0; 00081 00082 if(c->totalframes >= UINT_MAX/sizeof(uint32_t)){ 00083 av_log(s, AV_LOG_ERROR, "totalframes too large\n"); 00084 return -1; 00085 } 00086 00087 st = av_new_stream(s, 0); 00088 if (!st) 00089 return AVERROR(ENOMEM); 00090 00091 av_set_pts_info(st, 64, 1, samplerate); 00092 st->start_time = 0; 00093 st->duration = datalen; 00094 00095 framepos = url_ftell(s->pb) + 4*c->totalframes + 4; 00096 00097 for (i = 0; i < c->totalframes; i++) { 00098 uint32_t size = get_le32(s->pb); 00099 av_add_index_entry(st, framepos, i*framelen, size, 0, AVINDEX_KEYFRAME); 00100 framepos += size; 00101 } 00102 url_fskip(s->pb, 4); // seektable crc 00103 00104 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00105 st->codec->codec_id = CODEC_ID_TTA; 00106 st->codec->channels = channels; 00107 st->codec->sample_rate = samplerate; 00108 st->codec->bits_per_coded_sample = bps; 00109 00110 st->codec->extradata_size = url_ftell(s->pb) - start_offset; 00111 if(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)st->codec->extradata_size){ 00112 //this check is redundant as get_buffer should fail 00113 av_log(s, AV_LOG_ERROR, "extradata_size too large\n"); 00114 return -1; 00115 } 00116 st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE); 00117 url_fseek(s->pb, start_offset, SEEK_SET); 00118 get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size); 00119 00120 return 0; 00121 } 00122 00123 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt) 00124 { 00125 TTAContext *c = s->priv_data; 00126 AVStream *st = s->streams[0]; 00127 int size, ret; 00128 00129 // FIXME! 00130 if (c->currentframe > c->totalframes) 00131 return -1; 00132 00133 size = st->index_entries[c->currentframe].size; 00134 00135 ret = av_get_packet(s->pb, pkt, size); 00136 pkt->dts = st->index_entries[c->currentframe++].timestamp; 00137 return ret; 00138 } 00139 00140 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) 00141 { 00142 TTAContext *c = s->priv_data; 00143 AVStream *st = s->streams[stream_index]; 00144 int index = av_index_search_timestamp(st, timestamp, flags); 00145 if (index < 0) 00146 return -1; 00147 00148 c->currentframe = index; 00149 url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET); 00150 00151 return 0; 00152 } 00153 00154 AVInputFormat tta_demuxer = { 00155 "tta", 00156 NULL_IF_CONFIG_SMALL("True Audio"), 00157 sizeof(TTAContext), 00158 tta_probe, 00159 tta_read_header, 00160 tta_read_packet, 00161 NULL, 00162 tta_read_seek, 00163 .extensions = "tta", 00164 };