/* * 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 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 "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(NULL, AV_LOG_INFO, "mm: unknown chunk type 0x%x\n", type);            url_fseek(pb, length, SEEK_CUR);        }    }    return 0;}static int mm_read_close(AVFormatContext *s){    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,    mm_read_close,};