2 * American Laser Games MM Format Demuxer
3 * Copyright (c) 2006 Peter Ross
5 * This file is part of FFmpeg.
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.
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.
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
24 * American Laser Games MM Format Demuxer
25 * by Peter Ross (pross@xvid.org)
27 * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
28 * including Mad Dog McCree and Crime Patrol.
30 * Technical details here:
31 * http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
34 #include "libavutil/channel_layout.h"
35 #include "libavutil/intreadwrite.h"
39 #define MM_PREAMBLE_SIZE 6
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
51 #define MM_HEADER_LEN_V 0x16 /* video only */
52 #define MM_HEADER_LEN_AV 0x18 /* video + audio */
54 #define MM_PALETTE_COUNT 128
55 #define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
58 unsigned int audio_pts
, video_pts
;
61 static int probe(AVProbeData
*p
)
63 int len
, type
, fps
, w
, h
;
64 if (p
->buf_size
< MM_HEADER_LEN_AV
+ MM_PREAMBLE_SIZE
)
66 /* the first chunk is always the header */
67 if (AV_RL16(&p
->buf
[0]) != MM_TYPE_HEADER
)
69 len
= AV_RL32(&p
->buf
[2]);
70 if (len
!= MM_HEADER_LEN_V
&& len
!= MM_HEADER_LEN_AV
)
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)
77 type
= AV_RL16(&p
->buf
[len
]);
78 if (!type
|| type
> 0x31)
81 /* only return half certainty since this check is a bit sketchy */
82 return AVPROBE_SCORE_EXTENSION
;
85 static int read_header(AVFormatContext
*s
)
87 MmDemuxContext
*mm
= s
->priv_data
;
88 AVIOContext
*pb
= s
->pb
;
91 unsigned int type
, length
;
92 unsigned int frame_rate
, width
, height
;
95 length
= avio_rl32(pb
);
97 if (type
!= MM_TYPE_HEADER
)
98 return AVERROR_INVALIDDATA
;
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 */
109 st
= avformat_new_stream(s
, NULL
);
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
);
120 if (length
== MM_HEADER_LEN_AV
) {
121 st
= avformat_new_stream(s
, NULL
);
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 */
138 static int read_packet(AVFormatContext
*s
,
141 MmDemuxContext
*mm
= s
->priv_data
;
142 AVIOContext
*pb
= s
->pb
;
143 unsigned char preamble
[MM_PREAMBLE_SIZE
];
144 unsigned int type
, length
;
148 if (avio_read(pb
, preamble
, MM_PREAMBLE_SIZE
) != MM_PREAMBLE_SIZE
) {
152 type
= AV_RL16(&preamble
[0]);
153 length
= AV_RL16(&preamble
[2]);
156 case MM_TYPE_PALETTE
:
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
)
169 pkt
->size
= length
+ MM_PREAMBLE_SIZE
;
170 pkt
->stream_index
= 0;
171 pkt
->pts
= mm
->video_pts
;
172 if (type
!=MM_TYPE_PALETTE
)
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
++;
184 av_log(s
, AV_LOG_INFO
, "unknown chunk type 0x%x\n", type
);
185 avio_skip(pb
, length
);
190 AVInputFormat ff_mm_demuxer
= {
192 .long_name
= NULL_IF_CONFIG_SMALL("American Laser Games MM"),
193 .priv_data_size
= sizeof(MmDemuxContext
),
195 .read_header
= read_header
,
196 .read_packet
= read_packet
,