FFmpeg: libavformat/vc1test.c Source File

00001 /*
00002  * VC1 Test Bitstreams Format Demuxer
00003  * Copyright (c) 2006, 2008 Konstantin Shishkov
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 
00029 #include "libavutil/intreadwrite.h"
00030 #include "avformat.h"
00031 #include "internal.h"
00032 
00033 #define VC1_EXTRADATA_SIZE 4
00034 
00035 static int vc1t_probe(AVProbeData *p)
00036 {
00037     if (p->buf_size < 24)
00038         return 0;
00039     if (p->buf[3] != 0xC5 || AV_RL32(&p->buf[4]) != 4 || AV_RL32(&p->buf[20]) != 0xC)
00040         return 0;
00041 
00042     return AVPROBE_SCORE_MAX/2;
00043 }
00044 
00045 static int vc1t_read_header(AVFormatContext *s)
00046 {
00047     AVIOContext *pb = s->pb;
00048     AVStream *st;
00049     int frames;
00050     uint32_t fps;
00051 
00052     frames = avio_rl24(pb);
00053     if(avio_r8(pb) != 0xC5 || avio_rl32(pb) != 4)
00054         return -1;
00055 
00056     /* init video codec */
00057     st = avformat_new_stream(s, NULL);
00058     if (!st)
00059         return -1;
00060 
00061     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00062     st->codec->codec_id = AV_CODEC_ID_WMV3;
00063 
00064     st->codec->extradata = av_malloc(VC1_EXTRADATA_SIZE);
00065     st->codec->extradata_size = VC1_EXTRADATA_SIZE;
00066     avio_read(pb, st->codec->extradata, VC1_EXTRADATA_SIZE);
00067     st->codec->height = avio_rl32(pb);
00068     st->codec->width = avio_rl32(pb);
00069     if(avio_rl32(pb) != 0xC)
00070         return -1;
00071     avio_skip(pb, 8);
00072     fps = avio_rl32(pb);
00073     if(fps == 0xFFFFFFFF)
00074         avpriv_set_pts_info(st, 32, 1, 1000);
00075     else{
00076         if (!fps) {
00077             av_log(s, AV_LOG_ERROR, "Zero FPS specified, defaulting to 1 FPS\n");
00078             fps = 1;
00079         }
00080         avpriv_set_pts_info(st, 24, 1, fps);
00081         st->duration = frames;
00082     }
00083 
00084     return 0;
00085 }
00086 
00087 static int vc1t_read_packet(AVFormatContext *s,
00088                            AVPacket *pkt)
00089 {
00090     AVIOContext *pb = s->pb;
00091     int frame_size;
00092     int keyframe = 0;
00093     uint32_t pts;
00094 
00095     if(url_feof(pb))
00096         return AVERROR(EIO);
00097 
00098     frame_size = avio_rl24(pb);
00099     if(avio_r8(pb) & 0x80)
00100         keyframe = 1;
00101     pts = avio_rl32(pb);
00102     if(av_get_packet(pb, pkt, frame_size) < 0)
00103         return AVERROR(EIO);
00104     if(s->streams[0]->time_base.den == 1000)
00105         pkt->pts = pts;
00106     pkt->flags |= keyframe ? AV_PKT_FLAG_KEY : 0;
00107     pkt->pos -= 8;
00108 
00109     return pkt->size;
00110 }
00111 
00112 AVInputFormat ff_vc1t_demuxer = {
00113     .name           = "vc1test",
00114     .long_name      = NULL_IF_CONFIG_SMALL("VC-1 test bitstream"),
00115     .read_probe     = vc1t_probe,
00116     .read_header    = vc1t_read_header,
00117     .read_packet    = vc1t_read_packet,
00118     .flags          = AVFMT_GENERIC_INDEX,
00119 };