Libav
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00001 /* 00002 * Copyright (C) 2010 David Conrad 00003 * 00004 * This file is part of FFmpeg. 00005 * 00006 * FFmpeg is free software; you can redistribute it and/or 00007 * modify it under the terms of the GNU Lesser General Public 00008 * License as published by the Free Software Foundation; either 00009 * version 2.1 of the License, or (at your option) any later version. 00010 * 00011 * FFmpeg is distributed in the hope that it will be useful, 00012 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00014 * Lesser General Public License for more details. 00015 * 00016 * You should have received a copy of the GNU Lesser General Public 00017 * License along with FFmpeg; if not, write to the Free Software 00018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00019 */ 00020 00021 #include "libavcodec/bytestream.h" 00022 #include "avformat.h" 00023 #include "oggdec.h" 00024 00025 static int skeleton_header(AVFormatContext *s, int idx) 00026 { 00027 struct ogg *ogg = s->priv_data; 00028 struct ogg_stream *os = ogg->streams + idx; 00029 AVStream *st = s->streams[idx]; 00030 uint8_t *buf = os->buf + os->pstart; 00031 int version_major, version_minor; 00032 int64_t start_num, start_den, start_granule; 00033 int target_idx, start_time; 00034 00035 strcpy(st->codec->codec_name, "skeleton"); 00036 st->codec->codec_type = AVMEDIA_TYPE_DATA; 00037 00038 if (os->psize < 8) 00039 return -1; 00040 00041 if (!strncmp(buf, "fishead", 8)) { 00042 if (os->psize < 64) 00043 return -1; 00044 00045 version_major = AV_RL16(buf+8); 00046 version_minor = AV_RL16(buf+10); 00047 00048 if (version_major != 3) { 00049 av_log(s, AV_LOG_WARNING, "Unknown skeleton version %d.%d\n", 00050 version_major, version_minor); 00051 return -1; 00052 } 00053 00054 // This is the overall start time. We use it for the start time of 00055 // of the skeleton stream since if left unset lavf assumes 0, 00056 // which we don't want since skeleton is timeless 00057 // FIXME: the real meaning of this field is "start playback at 00058 // this time which can be in the middle of a packet 00059 start_num = AV_RL64(buf+12); 00060 start_den = AV_RL64(buf+20); 00061 00062 if (start_den) { 00063 av_reduce(&start_time, &st->time_base.den, start_num, start_den, INT_MAX); 00064 st->time_base.num = 1; 00065 os->lastpts = 00066 st->start_time = start_time; 00067 } 00068 } else if (!strncmp(buf, "fisbone", 8)) { 00069 if (os->psize < 52) 00070 return -1; 00071 00072 target_idx = ogg_find_stream(ogg, AV_RL32(buf+12)); 00073 start_granule = AV_RL64(buf+36); 00074 if (target_idx >= 0 && start_granule != -1) { 00075 ogg->streams[target_idx].lastpts = 00076 s->streams[target_idx]->start_time = ogg_gptopts(s, target_idx, start_granule, NULL); 00077 } 00078 } 00079 00080 return 1; 00081 } 00082 00083 const struct ogg_codec ff_skeleton_codec = { 00084 .magic = "fishead", 00085 .magicsize = 8, 00086 .header = skeleton_header, 00087 };