/*
  * 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

  * American Laser Games MM Format Demuxer

  * by Peter Ross (pross@xvid.org)

  *
  * 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 "libavutil/intreadwrite.h"

 #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 probe(AVProbeData *p)

 {

     int len, type, fps, w, h;
     if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
         return 0;

     /* the first chunk is always the header */

     if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)

         return 0;

     len = AV_RL32(&p->buf[2]);
     if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
         return 0;
     fps = AV_RL16(&p->buf[8]);
     w = AV_RL16(&p->buf[12]);
     h = AV_RL16(&p->buf[14]);
     if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
         return 0;
     type = AV_RL16(&p->buf[len]);
     if (!type || type > 0x31)

         return 0;
 
     /* only return half certainty since this check is a bit sketchy */
     return AVPROBE_SCORE_MAX / 2;
 }
 

 static int read_header(AVFormatContext *s,

                            AVFormatParameters *ap)
 {

     MmDemuxContext *mm = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *st;
 
     unsigned int type, length;
     unsigned int frame_rate, width, height;
 

     type = avio_rl16(pb);
     length = avio_rl32(pb);

 
     if (type != MM_TYPE_HEADER)
         return AVERROR_INVALIDDATA;
 
     /* read header */

     avio_rl16(pb);   /* total number of chunks */
     frame_rate = avio_rl16(pb);
     avio_rl16(pb);   /* ibm-pc video bios mode */
     width = avio_rl16(pb);
     height = avio_rl16(pb);

     avio_skip(pb, length - 10);  /* unknown data */

 
     /* video stream */
     st = av_new_stream(s, 0);
     if (!st)

         return AVERROR(ENOMEM);

     st->codec->codec_type = AVMEDIA_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 = AVMEDIA_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 read_packet(AVFormatContext *s,

                            AVPacket *pkt)
 {

     MmDemuxContext *mm = s->priv_data;

     AVIOContext *pb = s->pb;

     unsigned char preamble[MM_PREAMBLE_SIZE];
     unsigned int type, length;
 
     while(1) {
 

         if (avio_read(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 (avio_read(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(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);

             avio_skip(pb, length);

         }
     }
 
     return 0;
 }
 

 AVInputFormat ff_mm_demuxer = {

     "mm",

     NULL_IF_CONFIG_SMALL("American Laser Games MM format"),

     sizeof(MmDemuxContext),

     probe,
     read_header,
     read_packet,

 };