/* * 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 St, 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 { AVPaletteControl palette_control; 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_NOMEM; 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; st->codec->palctrl = &mm->palette_control; 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_NOMEM; 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->palette_control.palette_changed = 0; 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 char pal[MM_PALETTE_SIZE]; unsigned int type, length; int i; while(1) { if (get_buffer(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) { return AVERROR_IO; } type = AV_RL16(&preamble[0]); length = AV_RL16(&preamble[2]); switch(type) { case MM_TYPE_PALETTE : url_fseek(pb, 4, SEEK_CUR); /* unknown data */ if (get_buffer(pb, pal, MM_PALETTE_SIZE) != MM_PALETTE_SIZE) return AVERROR_IO; url_fseek(pb, length - (4 + MM_PALETTE_SIZE), SEEK_CUR); for (i=0; i<MM_PALETTE_COUNT; i++) { int r = pal[i*3 + 0]; int g = pal[i*3 + 1]; int b = pal[i*3 + 2]; mm->palette_control.palette[i] = (r << 16) | (g << 8) | (b); /* repeat palette, where each components is multiplied by four */ mm->palette_control.palette[i+128] = (r << 18) | (g << 10) | (b<<2); } mm->palette_control.palette_changed = 1; break; 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_NOMEM; memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE); if (get_buffer(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length) return AVERROR_IO; pkt->size = length + MM_PREAMBLE_SIZE; pkt->stream_index = 0; pkt->pts = mm->video_pts++; return 0; case MM_TYPE_AUDIO : if (av_get_packet(&s->pb, pkt, length)<0) return AVERROR_NOMEM; 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", "American Laser Games MM format", sizeof(MmDemuxContext), mm_probe, mm_read_header, mm_read_packet, mm_read_close, };