libavformat/vc1test.c

   1 /*
   2  * VC1 Test Bitstreams Format Demuxer
   3  * Copyright (c) 2006, 2008 Konstantin Shishkov
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file libavformat/vc1test.c
  24  * VC1 test bitstream file demuxer
  25  * by Konstantin Shishkov
  26  * Format specified in SMPTE standard 421 Annex L
  27  */
  28
  29 #include "libavutil/intreadwrite.h"
  30 #include "avformat.h"
  31
  32 #define VC1_EXTRADATA_SIZE 4
  33
  34 static int vc1t_probe(AVProbeData *p)
  35 {
  36     if (p->buf_size < 24)
  37         return 0;
  38     if (p->buf[3] != 0xC5 || AV_RL32(&p->buf[4]) != 4 || AV_RL32(&p->buf[20]) != 0xC)
  39         return 0;
  40
  41     return AVPROBE_SCORE_MAX/2;
  42 }
  43
  44 static int vc1t_read_header(AVFormatContext *s,
  45                            AVFormatParameters *ap)
  46 {
  47     ByteIOContext *pb = s->pb;
  48     AVStream *st;
  49     int frames;
  50     uint32_t fps;
  51
  52     frames = get_le24(pb);
  53     if(get_byte(pb) != 0xC5 || get_le32(pb) != 4)
  54         return -1;
  55
  56     /* init video codec */
  57     st = av_new_stream(s, 0);
  58     if (!st)
  59         return -1;
  60
  61     st->codec->codec_type = CODEC_TYPE_VIDEO;
  62     st->codec->codec_id = CODEC_ID_WMV3;
  63
  64     st->codec->extradata = av_malloc(VC1_EXTRADATA_SIZE);
  65     st->codec->extradata_size = VC1_EXTRADATA_SIZE;
  66     get_buffer(pb, st->codec->extradata, VC1_EXTRADATA_SIZE);
  67     st->codec->height = get_le32(pb);
  68     st->codec->width = get_le32(pb);
  69     if(get_le32(pb) != 0xC)
  70         return -1;
  71     url_fskip(pb, 8);
  72     fps = get_le32(pb);
  73     if(fps == 0xFFFFFFFF)
  74         av_set_pts_info(st, 32, 1, 1000);
  75     else{
  76         if (!fps) {
  77             av_log(s, AV_LOG_ERROR, "Zero FPS specified, defaulting to 1 FPS\n");
  78             fps = 1;
  79         }
  80         av_set_pts_info(st, 24, 1, fps);
  81         st->duration = frames;
  82     }
  83
  84     return 0;
  85 }
  86
  87 static int vc1t_read_packet(AVFormatContext *s,
  88                            AVPacket *pkt)
  89 {
  90     ByteIOContext *pb = s->pb;
  91     int frame_size;
  92     int keyframe = 0;
  93     uint32_t pts;
  94
  95     if(url_feof(pb))
  96         return AVERROR(EIO);
  97
  98     frame_size = get_le24(pb);
  99     if(get_byte(pb) & 0x80)
 100         keyframe = 1;
 101     pts = get_le32(pb);
 102     if(av_get_packet(pb, pkt, frame_size) < 0)
 103         return AVERROR(EIO);
 104     if(s->streams[0]->time_base.den == 1000)
 105         pkt->pts = pts;
 106     pkt->flags |= keyframe ? PKT_FLAG_KEY : 0;
 107     pkt->pos -= 8;
 108
 109     return pkt->size;
 110 }
 111
 112 AVInputFormat vc1t_demuxer = {
 113     "vc1test",
 114     NULL_IF_CONFIG_SMALL("VC-1 test bitstream format"),
 115     0,
 116     vc1t_probe,
 117     vc1t_read_header,
 118     vc1t_read_packet,
 119     .flags = AVFMT_GENERIC_INDEX,
 120 };