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  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.  
  57. typedef struct {
  58.   unsigned int audio_pts, video_pts;
  59. } MmDemuxContext;
  60.  
  61. static 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.  
  85. static 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.  
  138. static 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.  
  190. AVInputFormat 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.