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 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 "avformat.h"
  35
  36 #define MM_PREAMBLE_SIZE    6
  37
  38 #define MM_TYPE_HEADER      0x0
  39 #define MM_TYPE_INTER       0x5
  40 #define MM_TYPE_INTRA       0x8
  41 #define MM_TYPE_INTRA_HH    0xc
  42 #define MM_TYPE_INTER_HH    0xd
  43 #define MM_TYPE_INTRA_HHV   0xe
  44 #define MM_TYPE_INTER_HHV   0xf
  45 #define MM_TYPE_AUDIO       0x15
  46 #define MM_TYPE_PALETTE     0x31
  47
  48 #define MM_HEADER_LEN_V     0x16    /* video only */
  49 #define MM_HEADER_LEN_AV    0x18    /* video + audio */
  50
  51 #define MM_PALETTE_COUNT    128
  52 #define MM_PALETTE_SIZE     (MM_PALETTE_COUNT*3)
  53
  54 typedef struct {
  55   AVPaletteControl palette_control;
  56   unsigned int audio_pts, video_pts;
  57 } MmDemuxContext;
  58
  59 static int mm_probe(AVProbeData *p)
  60 {
  61     /* the first chunk is always the header */
  62     if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
  63         return 0;
  64     if (AV_RL32(&p->buf[2]) != MM_HEADER_LEN_V && AV_RL32(&p->buf[2]) != MM_HEADER_LEN_AV)
  65         return 0;
  66
  67     /* only return half certainty since this check is a bit sketchy */
  68     return AVPROBE_SCORE_MAX / 2;
  69 }
  70
  71 static int mm_read_header(AVFormatContext *s,
  72                            AVFormatParameters *ap)
  73 {
  74     MmDemuxContext *mm = s->priv_data;
  75     ByteIOContext *pb = s->pb;
  76     AVStream *st;
  77
  78     unsigned int type, length;
  79     unsigned int frame_rate, width, height;
  80
  81     type = get_le16(pb);
  82     length = get_le32(pb);
  83
  84     if (type != MM_TYPE_HEADER)
  85         return AVERROR_INVALIDDATA;
  86
  87     /* read header */
  88     get_le16(pb);   /* total number of chunks */
  89     frame_rate = get_le16(pb);
  90     get_le16(pb);   /* ibm-pc video bios mode */
  91     width = get_le16(pb);
  92     height = get_le16(pb);
  93     url_fseek(pb, length - 10, SEEK_CUR);  /* unknown data */
  94
  95     /* video stream */
  96     st = av_new_stream(s, 0);
  97     if (!st)
  98         return AVERROR(ENOMEM);
  99     st->codec->codec_type = CODEC_TYPE_VIDEO;
 100     st->codec->codec_id = CODEC_ID_MMVIDEO;
 101     st->codec->codec_tag = 0;  /* no fourcc */
 102     st->codec->width = width;
 103     st->codec->height = height;
 104     st->codec->palctrl = &mm->palette_control;
 105     av_set_pts_info(st, 64, 1, frame_rate);
 106
 107     /* audio stream */
 108     if (length == MM_HEADER_LEN_AV) {
 109         st = av_new_stream(s, 0);
 110         if (!st)
 111             return AVERROR(ENOMEM);
 112         st->codec->codec_type = CODEC_TYPE_AUDIO;
 113         st->codec->codec_tag = 0; /* no fourcc */
 114         st->codec->codec_id = CODEC_ID_PCM_U8;
 115         st->codec->channels = 1;
 116         st->codec->sample_rate = 8000;
 117         av_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
 118     }
 119
 120     mm->palette_control.palette_changed = 0;
 121     mm->audio_pts = 0;
 122     mm->video_pts = 0;
 123     return 0;
 124 }
 125
 126 static int mm_read_packet(AVFormatContext *s,
 127                            AVPacket *pkt)
 128 {
 129     MmDemuxContext *mm = s->priv_data;
 130     ByteIOContext *pb = s->pb;
 131     unsigned char preamble[MM_PREAMBLE_SIZE];
 132     unsigned char pal[MM_PALETTE_SIZE];
 133     unsigned int type, length;
 134     int i;
 135
 136     while(1) {
 137
 138         if (get_buffer(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
 139             return AVERROR(EIO);
 140         }
 141
 142         type = AV_RL16(&preamble[0]);
 143         length = AV_RL16(&preamble[2]);
 144
 145         switch(type) {
 146         case MM_TYPE_PALETTE :
 147             url_fseek(pb, 4, SEEK_CUR);  /* unknown data */
 148             if (get_buffer(pb, pal, MM_PALETTE_SIZE) != MM_PALETTE_SIZE)
 149                 return AVERROR(EIO);
 150             url_fseek(pb, length - (4 + MM_PALETTE_SIZE), SEEK_CUR);
 151
 152             for (i=0; i<MM_PALETTE_COUNT; i++) {
 153                 int r = pal[i*3 + 0];
 154                 int g = pal[i*3 + 1];
 155                 int b = pal[i*3 + 2];
 156                 mm->palette_control.palette[i] = (r << 16) | (g << 8) | (b);
 157                 /* repeat palette, where each components is multiplied by four */
 158                 mm->palette_control.palette[i+128] = (r << 18) | (g << 10) | (b<<2);
 159             }
 160             mm->palette_control.palette_changed = 1;
 161             break;
 162
 163         case MM_TYPE_INTER :
 164         case MM_TYPE_INTRA :
 165         case MM_TYPE_INTRA_HH :
 166         case MM_TYPE_INTER_HH :
 167         case MM_TYPE_INTRA_HHV :
 168         case MM_TYPE_INTER_HHV :
 169             /* output preamble + data */
 170             if (av_new_packet(pkt, length + MM_PREAMBLE_SIZE))
 171                 return AVERROR(ENOMEM);
 172             memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
 173             if (get_buffer(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
 174                 return AVERROR(EIO);
 175             pkt->size = length + MM_PREAMBLE_SIZE;
 176             pkt->stream_index = 0;
 177             pkt->pts = mm->video_pts++;
 178             return 0;
 179
 180         case MM_TYPE_AUDIO :
 181             if (av_get_packet(s->pb, pkt, length)<0)
 182                 return AVERROR(ENOMEM);
 183             pkt->size = length;
 184             pkt->stream_index = 1;
 185             pkt->pts = mm->audio_pts++;
 186             return 0;
 187
 188         default :
 189             av_log(NULL, AV_LOG_INFO, "mm: unknown chunk type 0x%x\n", type);
 190             url_fseek(pb, length, SEEK_CUR);
 191         }
 192     }
 193
 194     return 0;
 195 }
 196
 197 static int mm_read_close(AVFormatContext *s)
 198 {
 199     return 0;
 200 }
 201
 202 AVInputFormat mm_demuxer = {
 203     "mm",
 204     NULL_IF_CONFIG_SMALL("American Laser Games MM format"),
 205     sizeof(MmDemuxContext),
 206     mm_probe,
 207     mm_read_header,
 208     mm_read_packet,
 209     mm_read_close,
 210 };