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/*
* American Laser Games MM Format Demuxer
* Copyright (c) 2006 Peter Ross
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file libavformat/mm.c
* American Laser Games MM Format Demuxer
* by Peter Ross (suxen_drol at hotmail dot com)
*
* The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
* including Mad Dog McCree and Crime Patrol.
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#define MM_PREAMBLE_SIZE 6
#define MM_TYPE_HEADER 0x0
#define MM_TYPE_INTER 0x5
#define MM_TYPE_INTRA 0x8
#define MM_TYPE_INTRA_HH 0xc
#define MM_TYPE_INTER_HH 0xd
#define MM_TYPE_INTRA_HHV 0xe
#define MM_TYPE_INTER_HHV 0xf
#define MM_TYPE_AUDIO 0x15
#define MM_TYPE_PALETTE 0x31
#define MM_HEADER_LEN_V 0x16 /* video only */
#define MM_HEADER_LEN_AV 0x18 /* video + audio */
#define MM_PALETTE_COUNT 128
#define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
typedef struct {
unsigned int audio_pts, video_pts;
} MmDemuxContext;
static int mm_probe(AVProbeData *p)
{
/* the first chunk is always the header */
if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
return 0;
if (AV_RL32(&p->buf[2]) != MM_HEADER_LEN_V && AV_RL32(&p->buf[2]) != MM_HEADER_LEN_AV)
return 0;
/* only return half certainty since this check is a bit sketchy */
return AVPROBE_SCORE_MAX / 2;
}
static int mm_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
MmDemuxContext *mm = s->priv_data;
ByteIOContext *pb = s->pb;
AVStream *st;
unsigned int type, length;
unsigned int frame_rate, width, height;
type = get_le16(pb);
length = get_le32(pb);
if (type != MM_TYPE_HEADER)
return AVERROR_INVALIDDATA;
/* read header */
get_le16(pb); /* total number of chunks */
frame_rate = get_le16(pb);
get_le16(pb); /* ibm-pc video bios mode */
width = get_le16(pb);
height = get_le16(pb);
url_fseek(pb, length - 10, SEEK_CUR); /* unknown data */
/* video stream */
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = CODEC_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_MMVIDEO;
st->codec->codec_tag = 0; /* no fourcc */
st->codec->width = width;
st->codec->height = height;
av_set_pts_info(st, 64, 1, frame_rate);
/* audio stream */
if (length == MM_HEADER_LEN_AV) {
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_tag = 0; /* no fourcc */
st->codec->codec_id = CODEC_ID_PCM_U8;
st->codec->channels = 1;
st->codec->sample_rate = 8000;
av_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
}
mm->audio_pts = 0;
mm->video_pts = 0;
return 0;
}
static int mm_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
MmDemuxContext *mm = s->priv_data;
ByteIOContext *pb = s->pb;
unsigned char preamble[MM_PREAMBLE_SIZE];
unsigned int type, length;
while(1) {
if (get_buffer(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
return AVERROR(EIO);
}
type = AV_RL16(&preamble[0]);
length = AV_RL16(&preamble[2]);
switch(type) {
case MM_TYPE_PALETTE :
case MM_TYPE_INTER :
case MM_TYPE_INTRA :
case MM_TYPE_INTRA_HH :
case MM_TYPE_INTER_HH :
case MM_TYPE_INTRA_HHV :
case MM_TYPE_INTER_HHV :
/* output preamble + data */
if (av_new_packet(pkt, length + MM_PREAMBLE_SIZE))
return AVERROR(ENOMEM);
memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
if (get_buffer(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
return AVERROR(EIO);
pkt->size = length + MM_PREAMBLE_SIZE;
pkt->stream_index = 0;
pkt->pts = mm->video_pts;
if (type!=MM_TYPE_PALETTE)
mm->video_pts++;
return 0;
case MM_TYPE_AUDIO :
if (av_get_packet(s->pb, pkt, length)<0)
return AVERROR(ENOMEM);
pkt->size = length;
pkt->stream_index = 1;
pkt->pts = mm->audio_pts++;
return 0;
default :
av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
url_fseek(pb, length, SEEK_CUR);
}
}
return 0;
}
AVInputFormat mm_demuxer = {
"mm",
NULL_IF_CONFIG_SMALL("American Laser Games MM format"),
sizeof(MmDemuxContext),
mm_probe,
mm_read_header,
mm_read_packet,
};
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