libavformat/mm.c

   1 /*
   2  * American Laser Games MM Format Demuxer
   3  * Copyright (c) 2006 Peter Ross
   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 libavformat/mm.c
  24  * American Laser Games MM Format Demuxer
  25  * by Peter Ross (suxen_drol at hotmail dot com)
  26  *
  27  * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
  28  * including Mad Dog McCree and Crime Patrol.
  29  *
  30  * Technical details here:
  31  *  http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
  32  */
  33
  34 #include "libavutil/intreadwrite.h"
  35 #include "avformat.h"
  36
  37 #define MM_PREAMBLE_SIZE    6
  38
  39 #define MM_TYPE_HEADER      0x0
  40 #define MM_TYPE_INTER       0x5
  41 #define MM_TYPE_INTRA       0x8
  42 #define MM_TYPE_INTRA_HH    0xc
  43 #define MM_TYPE_INTER_HH    0xd
  44 #define MM_TYPE_INTRA_HHV   0xe
  45 #define MM_TYPE_INTER_HHV   0xf
  46 #define MM_TYPE_AUDIO       0x15
  47 #define MM_TYPE_PALETTE     0x31
  48
  49 #define MM_HEADER_LEN_V     0x16    /* video only */
  50 #define MM_HEADER_LEN_AV    0x18    /* video + audio */
  51
  52 #define MM_PALETTE_COUNT    128
  53 #define MM_PALETTE_SIZE     (MM_PALETTE_COUNT*3)
  54
  55 typedef struct {
  56   unsigned int audio_pts, video_pts;
  57 } MmDemuxContext;
  58
  59 static int mm_probe(AVProbeData *p)
  60 {
  61     int len, type, fps, w, h;
  62     if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
  63         return 0;
  64     /* the first chunk is always the header */
  65     if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
  66         return 0;
  67     len = AV_RL32(&p->buf[2]);
  68     if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
  69         return 0;
  70     fps = AV_RL16(&p->buf[8]);
  71     w = AV_RL16(&p->buf[12]);
  72     h = AV_RL16(&p->buf[14]);
  73     if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
  74         return 0;
  75     type = AV_RL16(&p->buf[len]);
  76     if (!type || type > 0x31)
  77         return 0;
  78
  79     /* only return half certainty since this check is a bit sketchy */
  80     return AVPROBE_SCORE_MAX / 2;
  81 }
  82
  83 static int mm_read_header(AVFormatContext *s,
  84                            AVFormatParameters *ap)
  85 {
  86     MmDemuxContext *mm = s->priv_data;
  87     ByteIOContext *pb = s->pb;
  88     AVStream *st;
  89
  90     unsigned int type, length;
  91     unsigned int frame_rate, width, height;
  92
  93     type = get_le16(pb);
  94     length = get_le32(pb);
  95
  96     if (type != MM_TYPE_HEADER)
  97         return AVERROR_INVALIDDATA;
  98
  99     /* read header */
 100     get_le16(pb);   /* total number of chunks */
 101     frame_rate = get_le16(pb);
 102     get_le16(pb);   /* ibm-pc video bios mode */
 103     width = get_le16(pb);
 104     height = get_le16(pb);
 105     url_fseek(pb, length - 10, SEEK_CUR);  /* unknown data */
 106
 107     /* video stream */
 108     st = av_new_stream(s, 0);
 109     if (!st)
 110         return AVERROR(ENOMEM);
 111     st->codec->codec_type = CODEC_TYPE_VIDEO;
 112     st->codec->codec_id = CODEC_ID_MMVIDEO;
 113     st->codec->codec_tag = 0;  /* no fourcc */
 114     st->codec->width = width;
 115     st->codec->height = height;
 116     av_set_pts_info(st, 64, 1, frame_rate);
 117
 118     /* audio stream */
 119     if (length == MM_HEADER_LEN_AV) {
 120         st = av_new_stream(s, 0);
 121         if (!st)
 122             return AVERROR(ENOMEM);
 123         st->codec->codec_type = CODEC_TYPE_AUDIO;
 124         st->codec->codec_tag = 0; /* no fourcc */
 125         st->codec->codec_id = CODEC_ID_PCM_U8;
 126         st->codec->channels = 1;
 127         st->codec->sample_rate = 8000;
 128         av_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
 129     }
 130
 131     mm->audio_pts = 0;
 132     mm->video_pts = 0;
 133     return 0;
 134 }
 135
 136 static int mm_read_packet(AVFormatContext *s,
 137                            AVPacket *pkt)
 138 {
 139     MmDemuxContext *mm = s->priv_data;
 140     ByteIOContext *pb = s->pb;
 141     unsigned char preamble[MM_PREAMBLE_SIZE];
 142     unsigned int type, length;
 143
 144     while(1) {
 145
 146         if (get_buffer(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
 147             return AVERROR(EIO);
 148         }
 149
 150         type = AV_RL16(&preamble[0]);
 151         length = AV_RL16(&preamble[2]);
 152
 153         switch(type) {
 154         case MM_TYPE_PALETTE :
 155         case MM_TYPE_INTER :
 156         case MM_TYPE_INTRA :
 157         case MM_TYPE_INTRA_HH :
 158         case MM_TYPE_INTER_HH :
 159         case MM_TYPE_INTRA_HHV :
 160         case MM_TYPE_INTER_HHV :
 161             /* output preamble + data */
 162             if (av_new_packet(pkt, length + MM_PREAMBLE_SIZE))
 163                 return AVERROR(ENOMEM);
 164             memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
 165             if (get_buffer(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
 166                 return AVERROR(EIO);
 167             pkt->size = length + MM_PREAMBLE_SIZE;
 168             pkt->stream_index = 0;
 169             pkt->pts = mm->video_pts;
 170             if (type!=MM_TYPE_PALETTE)
 171                 mm->video_pts++;
 172             return 0;
 173
 174         case MM_TYPE_AUDIO :
 175             if (av_get_packet(s->pb, pkt, length)<0)
 176                 return AVERROR(ENOMEM);
 177             pkt->size = length;
 178             pkt->stream_index = 1;
 179             pkt->pts = mm->audio_pts++;
 180             return 0;
 181
 182         default :
 183             av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
 184             url_fseek(pb, length, SEEK_CUR);
 185         }
 186     }
 187
 188     return 0;
 189 }
 190
 191 AVInputFormat mm_demuxer = {
 192     "mm",
 193     NULL_IF_CONFIG_SMALL("American Laser Games MM format"),
 194     sizeof(MmDemuxContext),
 195     mm_probe,
 196     mm_read_header,
 197     mm_read_packet,
 198 };