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 24 * American Laser Games MM Format Demuxer 25 * by Peter Ross (pross@xvid.org) 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/channel_layout.h" 35#include "libavutil/intreadwrite.h" 36#include "avformat.h" 37#include "internal.h" 38 39#define MM_PREAMBLE_SIZE 6 40 41#define MM_TYPE_HEADER 0x0 42#define MM_TYPE_INTER 0x5 43#define MM_TYPE_INTRA 0x8 44#define MM_TYPE_INTRA_HH 0xc 45#define MM_TYPE_INTER_HH 0xd 46#define MM_TYPE_INTRA_HHV 0xe 47#define MM_TYPE_INTER_HHV 0xf 48#define MM_TYPE_AUDIO 0x15 49#define MM_TYPE_PALETTE 0x31 50 51#define MM_HEADER_LEN_V 0x16 /* video only */ 52#define MM_HEADER_LEN_AV 0x18 /* video + audio */ 53 54#define MM_PALETTE_COUNT 128 55#define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3) 56 57typedef struct { 58 unsigned int audio_pts, video_pts; 59} MmDemuxContext; 60 61static int probe(AVProbeData *p) 62{ 63 int len, type, fps, w, h; 64 if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE) 65 return 0; 66 /* the first chunk is always the header */ 67 if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER) 68 return 0; 69 len = AV_RL32(&p->buf[2]); 70 if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV) 71 return 0; 72 fps = AV_RL16(&p->buf[8]); 73 w = AV_RL16(&p->buf[12]); 74 h = AV_RL16(&p->buf[14]); 75 if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048) 76 return 0; 77 type = AV_RL16(&p->buf[len]); 78 if (!type || type > 0x31) 79 return 0; 80 81 /* only return half certainty since this check is a bit sketchy */ 82 return AVPROBE_SCORE_EXTENSION; 83} 84 85static int read_header(AVFormatContext *s) 86{ 87 MmDemuxContext *mm = s->priv_data; 88 AVIOContext *pb = s->pb; 89 AVStream *st; 90 91 unsigned int type, length; 92 unsigned int frame_rate, width, height; 93 94 type = avio_rl16(pb); 95 length = avio_rl32(pb); 96 97 if (type != MM_TYPE_HEADER) 98 return AVERROR_INVALIDDATA; 99 100 /* read header */ 101 avio_rl16(pb); /* total number of chunks */ 102 frame_rate = avio_rl16(pb); 103 avio_rl16(pb); /* ibm-pc video bios mode */ 104 width = avio_rl16(pb); 105 height = avio_rl16(pb); 106 avio_skip(pb, length - 10); /* unknown data */ 107 108 /* video stream */ 109 st = avformat_new_stream(s, NULL); 110 if (!st) 111 return AVERROR(ENOMEM); 112 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 113 st->codec->codec_id = AV_CODEC_ID_MMVIDEO; 114 st->codec->codec_tag = 0; /* no fourcc */ 115 st->codec->width = width; 116 st->codec->height = height; 117 avpriv_set_pts_info(st, 64, 1, frame_rate); 118 119 /* audio stream */ 120 if (length == MM_HEADER_LEN_AV) { 121 st = avformat_new_stream(s, NULL); 122 if (!st) 123 return AVERROR(ENOMEM); 124 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 125 st->codec->codec_tag = 0; /* no fourcc */ 126 st->codec->codec_id = AV_CODEC_ID_PCM_U8; 127 st->codec->channels = 1; 128 st->codec->channel_layout = AV_CH_LAYOUT_MONO; 129 st->codec->sample_rate = 8000; 130 avpriv_set_pts_info(st, 64, 1, 8000); /* 8000 hz */ 131 } 132 133 mm->audio_pts = 0; 134 mm->video_pts = 0; 135 return 0; 136} 137 138static int read_packet(AVFormatContext *s, 139 AVPacket *pkt) 140{ 141 MmDemuxContext *mm = s->priv_data; 142 AVIOContext *pb = s->pb; 143 unsigned char preamble[MM_PREAMBLE_SIZE]; 144 unsigned int type, length; 145 146 while(1) { 147 148 if (avio_read(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) { 149 return AVERROR(EIO); 150 } 151 152 type = AV_RL16(&preamble[0]); 153 length = AV_RL16(&preamble[2]); 154 155 switch(type) { 156 case MM_TYPE_PALETTE : 157 case MM_TYPE_INTER : 158 case MM_TYPE_INTRA : 159 case MM_TYPE_INTRA_HH : 160 case MM_TYPE_INTER_HH : 161 case MM_TYPE_INTRA_HHV : 162 case MM_TYPE_INTER_HHV : 163 /* output preamble + data */ 164 if (av_new_packet(pkt, length + MM_PREAMBLE_SIZE)) 165 return AVERROR(ENOMEM); 166 memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE); 167 if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length) 168 return AVERROR(EIO); 169 pkt->size = length + MM_PREAMBLE_SIZE; 170 pkt->stream_index = 0; 171 pkt->pts = mm->video_pts; 172 if (type!=MM_TYPE_PALETTE) 173 mm->video_pts++; 174 return 0; 175 176 case MM_TYPE_AUDIO : 177 if (av_get_packet(s->pb, pkt, length)<0) 178 return AVERROR(ENOMEM); 179 pkt->stream_index = 1; 180 pkt->pts = mm->audio_pts++; 181 return 0; 182 183 default : 184 av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type); 185 avio_skip(pb, length); 186 } 187 } 188} 189 190AVInputFormat ff_mm_demuxer = { 191 .name = "mm", 192 .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM"), 193 .priv_data_size = sizeof(MmDemuxContext), 194 .read_probe = probe, 195 .read_header = read_header, 196 .read_packet = read_packet, 197}; 198