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 (suxen_drol at hotmail dot com)
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
36 #define MM_PREAMBLE_SIZE 6
38 #define MM_TYPE_HEADER 0x0
39 #define MM_TYPE_INTER 0x5
40 #define MM_TYPE_INTRA 0x8
41 #define MM_TYPE_INTRA_HH 0xc
42 #define MM_TYPE_INTER_HH 0xd
43 #define MM_TYPE_INTRA_HHV 0xe
44 #define MM_TYPE_INTER_HHV 0xf
45 #define MM_TYPE_AUDIO 0x15
46 #define MM_TYPE_PALETTE 0x31
48 #define MM_HEADER_LEN_V 0x16 /* video only */
49 #define MM_HEADER_LEN_AV 0x18 /* video + audio */
51 #define MM_PALETTE_COUNT 128
52 #define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
55 unsigned int audio_pts
, video_pts
;
58 static int mm_probe(AVProbeData
*p
)
60 /* the first chunk is always the header */
61 if (AV_RL16(&p
->buf
[0]) != MM_TYPE_HEADER
)
63 if (AV_RL32(&p
->buf
[2]) != MM_HEADER_LEN_V
&& AV_RL32(&p
->buf
[2]) != MM_HEADER_LEN_AV
)
66 /* only return half certainty since this check is a bit sketchy */
67 return AVPROBE_SCORE_MAX
/ 2;
70 static int mm_read_header(AVFormatContext
*s
,
71 AVFormatParameters
*ap
)
73 MmDemuxContext
*mm
= s
->priv_data
;
74 ByteIOContext
*pb
= s
->pb
;
77 unsigned int type
, length
;
78 unsigned int frame_rate
, width
, height
;
81 length
= get_le32(pb
);
83 if (type
!= MM_TYPE_HEADER
)
84 return AVERROR_INVALIDDATA
;
87 get_le16(pb
); /* total number of chunks */
88 frame_rate
= get_le16(pb
);
89 get_le16(pb
); /* ibm-pc video bios mode */
91 height
= get_le16(pb
);
92 url_fseek(pb
, length
- 10, SEEK_CUR
); /* unknown data */
95 st
= av_new_stream(s
, 0);
97 return AVERROR(ENOMEM
);
98 st
->codec
->codec_type
= CODEC_TYPE_VIDEO
;
99 st
->codec
->codec_id
= CODEC_ID_MMVIDEO
;
100 st
->codec
->codec_tag
= 0; /* no fourcc */
101 st
->codec
->width
= width
;
102 st
->codec
->height
= height
;
103 av_set_pts_info(st
, 64, 1, frame_rate
);
106 if (length
== MM_HEADER_LEN_AV
) {
107 st
= av_new_stream(s
, 0);
109 return AVERROR(ENOMEM
);
110 st
->codec
->codec_type
= CODEC_TYPE_AUDIO
;
111 st
->codec
->codec_tag
= 0; /* no fourcc */
112 st
->codec
->codec_id
= CODEC_ID_PCM_U8
;
113 st
->codec
->channels
= 1;
114 st
->codec
->sample_rate
= 8000;
115 av_set_pts_info(st
, 64, 1, 8000); /* 8000 hz */
123 static int mm_read_packet(AVFormatContext
*s
,
126 MmDemuxContext
*mm
= s
->priv_data
;
127 ByteIOContext
*pb
= s
->pb
;
128 unsigned char preamble
[MM_PREAMBLE_SIZE
];
129 unsigned int type
, length
;
133 if (get_buffer(pb
, preamble
, MM_PREAMBLE_SIZE
) != MM_PREAMBLE_SIZE
) {
137 type
= AV_RL16(&preamble
[0]);
138 length
= AV_RL16(&preamble
[2]);
141 case MM_TYPE_PALETTE
:
144 case MM_TYPE_INTRA_HH
:
145 case MM_TYPE_INTER_HH
:
146 case MM_TYPE_INTRA_HHV
:
147 case MM_TYPE_INTER_HHV
:
148 /* output preamble + data */
149 if (av_new_packet(pkt
, length
+ MM_PREAMBLE_SIZE
))
150 return AVERROR(ENOMEM
);
151 memcpy(pkt
->data
, preamble
, MM_PREAMBLE_SIZE
);
152 if (get_buffer(pb
, pkt
->data
+ MM_PREAMBLE_SIZE
, length
) != length
)
154 pkt
->size
= length
+ MM_PREAMBLE_SIZE
;
155 pkt
->stream_index
= 0;
156 pkt
->pts
= mm
->video_pts
;
157 if (type
!=MM_TYPE_PALETTE
)
162 if (av_get_packet(s
->pb
, pkt
, length
)<0)
163 return AVERROR(ENOMEM
);
165 pkt
->stream_index
= 1;
166 pkt
->pts
= mm
->audio_pts
++;
170 av_log(NULL
, AV_LOG_INFO
, "mm: unknown chunk type 0x%x\n", type
);
171 url_fseek(pb
, length
, SEEK_CUR
);
178 AVInputFormat mm_demuxer
= {
180 NULL_IF_CONFIG_SMALL("American Laser Games MM format"),
181 sizeof(MmDemuxContext
),