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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 MmDemuxContext {
58   unsigned int audio_pts, video_pts;
59 } MmDemuxContext;
60 
probe(const AVProbeData * p)61 static int probe(const 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 
read_header(AVFormatContext * s)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->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
113     st->codecpar->codec_id = AV_CODEC_ID_MMVIDEO;
114     st->codecpar->codec_tag = 0;  /* no fourcc */
115     st->codecpar->width = width;
116     st->codecpar->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->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
125         st->codecpar->codec_tag = 0; /* no fourcc */
126         st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
127         st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
128         st->codecpar->sample_rate = 8000;
129         avpriv_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
130     }
131 
132     mm->audio_pts = 0;
133     mm->video_pts = 0;
134     return 0;
135 }
136 
read_packet(AVFormatContext * s,AVPacket * pkt)137 static int read_packet(AVFormatContext *s,
138                            AVPacket *pkt)
139 {
140     MmDemuxContext *mm = s->priv_data;
141     AVIOContext *pb = s->pb;
142     unsigned char preamble[MM_PREAMBLE_SIZE];
143     unsigned int type, length;
144     int ret;
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 ((ret = av_new_packet(pkt, length + MM_PREAMBLE_SIZE)) < 0)
165                 return ret;
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 (s->nb_streams < 2)
178                 return AVERROR_INVALIDDATA;
179             if ((ret = av_get_packet(s->pb, pkt, length)) < 0)
180                 return ret;
181             pkt->stream_index = 1;
182             pkt->pts = mm->audio_pts++;
183             return 0;
184 
185         default :
186             av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
187             avio_skip(pb, length);
188         }
189     }
190 }
191 
192 const AVInputFormat ff_mm_demuxer = {
193     .name           = "mm",
194     .long_name      = NULL_IF_CONFIG_SMALL("American Laser Games MM"),
195     .priv_data_size = sizeof(MmDemuxContext),
196     .read_probe     = probe,
197     .read_header    = read_header,
198     .read_packet    = read_packet,
199 };
200