FFmpeg: libavformat/ingenientdec.c Source File

00001 /*
00002  * RAW Ingenient MJPEG demuxer
00003  * Copyright (c) 2005 Alex Beregszaszi
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 
00022 #include "avformat.h"
00023 #include "rawdec.h"
00024 
00025 // http://www.artificis.hu/files/texts/ingenient.txt
00026 static int ingenient_read_packet(AVFormatContext *s, AVPacket *pkt)
00027 {
00028     int ret, size, w, h, unk1, unk2;
00029 
00030     if (avio_rl32(s->pb) != MKTAG('M', 'J', 'P', 'G'))
00031         return AVERROR(EIO); // FIXME
00032 
00033     size = avio_rl32(s->pb);
00034 
00035     w = avio_rl16(s->pb);
00036     h = avio_rl16(s->pb);
00037 
00038     avio_skip(s->pb, 8); // zero + size (padded?)
00039     avio_skip(s->pb, 2);
00040     unk1 = avio_rl16(s->pb);
00041     unk2 = avio_rl16(s->pb);
00042     avio_skip(s->pb, 22); // ASCII timestamp
00043 
00044     av_log(s, AV_LOG_DEBUG, "Ingenient packet: size=%d, width=%d, height=%d, unk1=%d unk2=%d\n",
00045         size, w, h, unk1, unk2);
00046 
00047     if (av_new_packet(pkt, size) < 0)
00048         return AVERROR(ENOMEM);
00049 
00050     pkt->pos = avio_tell(s->pb);
00051     pkt->stream_index = 0;
00052     ret = avio_read(s->pb, pkt->data, size);
00053     if (ret < 0) {
00054         av_free_packet(pkt);
00055         return ret;
00056     }
00057     pkt->size = ret;
00058     return ret;
00059 }
00060 
00061 AVInputFormat ff_ingenient_demuxer = {
00062     "ingenient",
00063     NULL_IF_CONFIG_SMALL("raw Ingenient MJPEG"),
00064     sizeof(FFRawVideoDemuxerContext),
00065     NULL,
00066     ff_raw_video_read_header,
00067     ingenient_read_packet,
00068     .flags= AVFMT_GENERIC_INDEX,
00069     .extensions = "cgi", // FIXME
00070     .value = CODEC_ID_MJPEG,
00071     .priv_class = &ff_rawvideo_demuxer_class,
00072 };