LCOV - code coverage report
Current view: top level - libavformat - mm.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 70 82 85.4 %
Date: 2017-12-15 11:05:35 Functions: 3 3 100.0 %

          Line data    Source code
       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 MmDemuxContext {
      58             :   unsigned int audio_pts, video_pts;
      59             : } MmDemuxContext;
      60             : 
      61        6130 : static int probe(AVProbeData *p)
      62             : {
      63             :     int len, type, fps, w, h;
      64        6130 :     if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
      65           0 :         return 0;
      66             :     /* the first chunk is always the header */
      67        6130 :     if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
      68        4997 :         return 0;
      69        1133 :     len = AV_RL32(&p->buf[2]);
      70        1133 :     if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
      71        1132 :         return 0;
      72           1 :     fps = AV_RL16(&p->buf[8]);
      73           1 :     w = AV_RL16(&p->buf[12]);
      74           1 :     h = AV_RL16(&p->buf[14]);
      75           1 :     if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
      76           0 :         return 0;
      77           1 :     type = AV_RL16(&p->buf[len]);
      78           1 :     if (!type || type > 0x31)
      79           0 :         return 0;
      80             : 
      81             :     /* only return half certainty since this check is a bit sketchy */
      82           1 :     return AVPROBE_SCORE_EXTENSION;
      83             : }
      84             : 
      85           1 : static int read_header(AVFormatContext *s)
      86             : {
      87           1 :     MmDemuxContext *mm = s->priv_data;
      88           1 :     AVIOContext *pb = s->pb;
      89             :     AVStream *st;
      90             : 
      91             :     unsigned int type, length;
      92             :     unsigned int frame_rate, width, height;
      93             : 
      94           1 :     type = avio_rl16(pb);
      95           1 :     length = avio_rl32(pb);
      96             : 
      97           1 :     if (type != MM_TYPE_HEADER)
      98           0 :         return AVERROR_INVALIDDATA;
      99             : 
     100             :     /* read header */
     101           1 :     avio_rl16(pb);   /* total number of chunks */
     102           1 :     frame_rate = avio_rl16(pb);
     103           1 :     avio_rl16(pb);   /* ibm-pc video bios mode */
     104           1 :     width = avio_rl16(pb);
     105           1 :     height = avio_rl16(pb);
     106           1 :     avio_skip(pb, length - 10);  /* unknown data */
     107             : 
     108             :     /* video stream */
     109           1 :     st = avformat_new_stream(s, NULL);
     110           1 :     if (!st)
     111           0 :         return AVERROR(ENOMEM);
     112           1 :     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
     113           1 :     st->codecpar->codec_id = AV_CODEC_ID_MMVIDEO;
     114           1 :     st->codecpar->codec_tag = 0;  /* no fourcc */
     115           1 :     st->codecpar->width = width;
     116           1 :     st->codecpar->height = height;
     117           1 :     avpriv_set_pts_info(st, 64, 1, frame_rate);
     118             : 
     119             :     /* audio stream */
     120           1 :     if (length == MM_HEADER_LEN_AV) {
     121           1 :         st = avformat_new_stream(s, NULL);
     122           1 :         if (!st)
     123           0 :             return AVERROR(ENOMEM);
     124           1 :         st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
     125           1 :         st->codecpar->codec_tag = 0; /* no fourcc */
     126           1 :         st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
     127           1 :         st->codecpar->channels = 1;
     128           1 :         st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
     129           1 :         st->codecpar->sample_rate = 8000;
     130           1 :         avpriv_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
     131             :     }
     132             : 
     133           1 :     mm->audio_pts = 0;
     134           1 :     mm->video_pts = 0;
     135           1 :     return 0;
     136             : }
     137             : 
     138         100 : static int read_packet(AVFormatContext *s,
     139             :                            AVPacket *pkt)
     140             : {
     141         100 :     MmDemuxContext *mm = s->priv_data;
     142         100 :     AVIOContext *pb = s->pb;
     143             :     unsigned char preamble[MM_PREAMBLE_SIZE];
     144             :     unsigned int type, length;
     145             : 
     146             :     while(1) {
     147             : 
     148         100 :         if (avio_read(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
     149           1 :             return AVERROR(EIO);
     150             :         }
     151             : 
     152          99 :         type = AV_RL16(&preamble[0]);
     153          99 :         length = AV_RL16(&preamble[2]);
     154             : 
     155          99 :         switch(type) {
     156          32 :         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          32 :             if (av_new_packet(pkt, length + MM_PREAMBLE_SIZE))
     165           0 :                 return AVERROR(ENOMEM);
     166          32 :             memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
     167          32 :             if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
     168           0 :                 return AVERROR(EIO);
     169          32 :             pkt->size = length + MM_PREAMBLE_SIZE;
     170          32 :             pkt->stream_index = 0;
     171          32 :             pkt->pts = mm->video_pts;
     172          32 :             if (type!=MM_TYPE_PALETTE)
     173          31 :                 mm->video_pts++;
     174          32 :             return 0;
     175             : 
     176          67 :         case MM_TYPE_AUDIO :
     177          67 :             if (av_get_packet(s->pb, pkt, length)<0)
     178           0 :                 return AVERROR(ENOMEM);
     179          67 :             pkt->stream_index = 1;
     180          67 :             pkt->pts = mm->audio_pts++;
     181          67 :             return 0;
     182             : 
     183           0 :         default :
     184           0 :             av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
     185           0 :             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             : };

Generated by: LCOV version 1.13