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