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
  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 #include "demux.h"
  32 #include "internal.h"
  33
  34 #define VC1_EXTRADATA_SIZE 4
  35
  36 static int vc1t_probe(const AVProbeData *p)
  37 {
  38     uint32_t size;
  39
  40     if (p->buf_size < 24)
  41         return 0;
  42
  43     size = AV_RL32(&p->buf[4]);
  44     if (p->buf[3] != 0xC5 || size < 4 || size > p->buf_size - 20 ||
  45         AV_RL32(&p->buf[size+16]) != 0xC)
  46         return 0;
  47
  48     return AVPROBE_SCORE_EXTENSION;
  49 }
  50
  51 static int vc1t_read_header(AVFormatContext *s)
  52 {
  53     AVIOContext *pb = s->pb;
  54     AVStream *st;
  55     int frames, ret;
  56     uint32_t fps;
  57     uint32_t size;
  58
  59     frames = avio_rl24(pb);
  60     if (avio_r8(pb) != 0xC5 || ((size = avio_rl32(pb)) < 4))
  61         return AVERROR_INVALIDDATA;
  62
  63     /* init video codec */
  64     st = avformat_new_stream(s, NULL);
  65     if (!st)
  66         return AVERROR(ENOMEM);
  67
  68     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
  69     st->codecpar->codec_id = AV_CODEC_ID_WMV3;
  70
  71     if ((ret = ff_get_extradata(s, st->codecpar, pb, VC1_EXTRADATA_SIZE)) < 0)
  72         return ret;
  73
  74     avio_skip(pb, size - 4);
  75     st->codecpar->height = avio_rl32(pb);
  76     st->codecpar->width = avio_rl32(pb);
  77     if(avio_rl32(pb) != 0xC)
  78         return AVERROR_INVALIDDATA;
  79     avio_skip(pb, 8);
  80     fps = avio_rl32(pb);
  81     if(fps == 0xFFFFFFFF)
  82         avpriv_set_pts_info(st, 32, 1, 1000);
  83     else{
  84         if (!fps) {
  85             av_log(s, AV_LOG_ERROR, "Zero FPS specified, defaulting to 1 FPS\n");
  86             fps = 1;
  87         }
  88         avpriv_set_pts_info(st, 24, 1, fps);
  89         st->duration = frames;
  90     }
  91
  92     return 0;
  93 }
  94
  95 static int vc1t_read_packet(AVFormatContext *s,
  96                            AVPacket *pkt)
  97 {
  98     AVIOContext *pb = s->pb;
  99     int frame_size;
 100     int keyframe = 0;
 101     uint32_t pts;
 102
 103     if(avio_feof(pb))
 104         return AVERROR_EOF;
 105
 106     frame_size = avio_rl24(pb);
 107     if(avio_r8(pb) & 0x80)
 108         keyframe = 1;
 109     pts = avio_rl32(pb);
 110     if(av_get_packet(pb, pkt, frame_size) < 0)
 111         return AVERROR_INVALIDDATA;
 112     if(s->streams[0]->time_base.den == 1000)
 113         pkt->pts = pts;
 114     pkt->flags |= keyframe ? AV_PKT_FLAG_KEY : 0;
 115     pkt->pos -= 8;
 116
 117     return pkt->size;
 118 }
 119
 120 const FFInputFormat ff_vc1t_demuxer = {
 121     .p.name         = "vc1test",
 122     .p.long_name    = NULL_IF_CONFIG_SMALL("VC-1 test bitstream"),
 123     .p.extensions   = "rcv",
 124     .p.flags        = AVFMT_GENERIC_INDEX,
 125     .read_probe     = vc1t_probe,
 126     .read_header    = vc1t_read_header,
 127     .read_packet    = vc1t_read_packet,
 128 };