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/libavformat/dfa.c

http://github.com/FFmpeg/FFmpeg
C | 130 lines | 93 code | 17 blank | 20 comment | 23 complexity | e843642c7c9c0ca2dab300ce8c53ee2a MD5 | raw file
  1/*
  2 * Chronomaster DFA Format Demuxer
  3 * Copyright (c) 2011 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#include <inttypes.h>
 23
 24#include "libavutil/intreadwrite.h"
 25#include "avformat.h"
 26#include "internal.h"
 27
 28static int dfa_probe(const AVProbeData *p)
 29{
 30    if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('D', 'F', 'I', 'A'))
 31        return 0;
 32
 33    if (AV_RL32(p->buf + 16) != 0x80)
 34        return AVPROBE_SCORE_MAX / 4;
 35
 36    return AVPROBE_SCORE_MAX;
 37}
 38
 39static int dfa_read_header(AVFormatContext *s)
 40{
 41    AVIOContext *pb = s->pb;
 42    AVStream *st;
 43    int frames, ret;
 44    int version;
 45    uint32_t mspf;
 46
 47    if (avio_rl32(pb) != MKTAG('D', 'F', 'I', 'A')) {
 48        av_log(s, AV_LOG_ERROR, "Invalid magic for DFA\n");
 49        return AVERROR_INVALIDDATA;
 50    }
 51
 52    version = avio_rl16(pb);
 53    frames = avio_rl16(pb);
 54
 55    st = avformat_new_stream(s, NULL);
 56    if (!st)
 57        return AVERROR(ENOMEM);
 58
 59    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 60    st->codecpar->codec_id   = AV_CODEC_ID_DFA;
 61    st->codecpar->width      = avio_rl16(pb);
 62    st->codecpar->height     = avio_rl16(pb);
 63    mspf = avio_rl32(pb);
 64    if (!mspf) {
 65        av_log(s, AV_LOG_WARNING, "Zero FPS reported, defaulting to 10\n");
 66        mspf = 100;
 67    }
 68    avpriv_set_pts_info(st, 24, mspf, 1000);
 69    avio_skip(pb, 128 - 16); // padding
 70    st->duration = frames;
 71
 72    if ((ret = ff_alloc_extradata(st->codecpar, 2)) < 0)
 73        return ret;
 74    AV_WL16(st->codecpar->extradata, version);
 75    if (version == 0x100)
 76        st->sample_aspect_ratio = (AVRational){2, 1};
 77
 78    return 0;
 79}
 80
 81static int dfa_read_packet(AVFormatContext *s, AVPacket *pkt)
 82{
 83    AVIOContext *pb = s->pb;
 84    uint32_t frame_size;
 85    int ret, first = 1;
 86
 87    if (avio_feof(pb))
 88        return AVERROR_EOF;
 89
 90    if (av_get_packet(pb, pkt, 12) != 12)
 91        return AVERROR(EIO);
 92    while (!avio_feof(pb)) {
 93        if (!first) {
 94            ret = av_append_packet(pb, pkt, 12);
 95            if (ret < 0) {
 96                return ret;
 97            }
 98        } else
 99            first = 0;
100        frame_size = AV_RL32(pkt->data + pkt->size - 8);
101        if (frame_size > INT_MAX - 4) {
102            av_log(s, AV_LOG_ERROR, "Too large chunk size: %"PRIu32"\n", frame_size);
103            return AVERROR(EIO);
104        }
105        if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {
106            if (frame_size) {
107                av_log(s, AV_LOG_WARNING,
108                       "skipping %"PRIu32" bytes of end-of-frame marker chunk\n",
109                       frame_size);
110                avio_skip(pb, frame_size);
111            }
112            return 0;
113        }
114        ret = av_append_packet(pb, pkt, frame_size);
115        if (ret < 0) {
116            return ret;
117        }
118    }
119
120    return 0;
121}
122
123AVInputFormat ff_dfa_demuxer = {
124    .name           = "dfa",
125    .long_name      = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
126    .read_probe     = dfa_probe,
127    .read_header    = dfa_read_header,
128    .read_packet    = dfa_read_packet,
129    .flags          = AVFMT_GENERIC_INDEX,
130};