FFmpeg: libavformat/ivfdec.c Source File

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 "avformat.h"
00022 #include "riff.h"
00023 #include "libavutil/intreadwrite.h"
00024 
00025 static int probe(AVProbeData *p)
00026 {
00027     if (AV_RL32(p->buf) == MKTAG('D','K','I','F')
00028         && !AV_RL16(p->buf+4) && AV_RL16(p->buf+6) == 32)
00029         return AVPROBE_SCORE_MAX-2;
00030 
00031     return 0;
00032 }
00033 
00034 static int read_header(AVFormatContext *s, AVFormatParameters *ap)
00035 {
00036     AVStream *st;
00037     AVRational time_base;
00038 
00039     avio_rl32(s->pb); // DKIF
00040     avio_rl16(s->pb); // version
00041     avio_rl16(s->pb); // header size
00042 
00043     st = av_new_stream(s, 0);
00044     if (!st)
00045         return AVERROR(ENOMEM);
00046 
00047 
00048     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00049     st->codec->codec_tag  = avio_rl32(s->pb);
00050     st->codec->codec_id   = ff_codec_get_id(ff_codec_bmp_tags, st->codec->codec_tag);
00051     st->codec->width      = avio_rl16(s->pb);
00052     st->codec->height     = avio_rl16(s->pb);
00053     time_base.den         = avio_rl32(s->pb);
00054     time_base.num         = avio_rl32(s->pb);
00055     st->duration          = avio_rl64(s->pb);
00056 
00057     st->need_parsing      = AVSTREAM_PARSE_HEADERS;
00058 
00059     if (!time_base.den || !time_base.num) {
00060         av_log(s, AV_LOG_ERROR, "Invalid frame rate\n");
00061         return AVERROR_INVALIDDATA;
00062     }
00063 
00064     av_set_pts_info(st, 64, time_base.num, time_base.den);
00065 
00066     return 0;
00067 }
00068 
00069 static int read_packet(AVFormatContext *s, AVPacket *pkt)
00070 {
00071     int ret, size = avio_rl32(s->pb);
00072     int64_t   pts = avio_rl64(s->pb);
00073 
00074     ret = av_get_packet(s->pb, pkt, size);
00075     pkt->stream_index = 0;
00076     pkt->pts          = pts;
00077     pkt->pos         -= 12;
00078 
00079     return ret;
00080 }
00081 
00082 AVInputFormat ff_ivf_demuxer = {
00083     "ivf",
00084     NULL_IF_CONFIG_SMALL("On2 IVF"),
00085     0,
00086     probe,
00087     read_header,
00088     read_packet,
00089     .flags= AVFMT_GENERIC_INDEX,
00090     .codec_tag = (const AVCodecTag*[]){ff_codec_bmp_tags, 0},
00091 };