1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
/*
* American Laser Games MM Format Demuxer
* Copyright (c) 2006 Peter Ross
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file mm.c
* American Laser Games MM Format Demuxer
* by Peter Ross (suxen_drol at hotmail dot com)
*
* The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
* including Mad Dog McCree and Crime Patrol.
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
*/
#include "avformat.h"
#define MM_PREAMBLE_SIZE 6
#define MM_TYPE_HEADER 0x0
#define MM_TYPE_INTER 0x5
#define MM_TYPE_INTRA 0x8
#define MM_TYPE_INTRA_HH 0xc
#define MM_TYPE_INTER_HH 0xd
#define MM_TYPE_INTRA_HHV 0xe
#define MM_TYPE_INTER_HHV 0xf
#define MM_TYPE_AUDIO 0x15
#define MM_TYPE_PALETTE 0x31
#define MM_HEADER_LEN_V 0x16 /* video only */
#define MM_HEADER_LEN_AV 0x18 /* video + audio */
#define MM_PALETTE_COUNT 128
#define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
typedef struct {
AVPaletteControl palette_control;
unsigned int audio_pts, video_pts;
} MmDemuxContext;
static int mm_probe(AVProbeData *p)
{
/* the first chunk is always the header */
if (p->buf_size < MM_PREAMBLE_SIZE)
return 0;
if (LE_16(&p->buf[0]) != MM_TYPE_HEADER)
return 0;
if (LE_32(&p->buf[2]) != MM_HEADER_LEN_V && LE_32(&p->buf[2]) != MM_HEADER_LEN_AV)
return 0;
/* only return half certainty since this check is a bit sketchy */
return AVPROBE_SCORE_MAX / 2;
}
static int mm_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
MmDemuxContext *mm = (MmDemuxContext *)s->priv_data;
ByteIOContext *pb = &s->pb;
AVStream *st;
unsigned int type, length;
unsigned int frame_rate, width, height;
type = get_le16(pb);
length = get_le32(pb);
if (type != MM_TYPE_HEADER)
return AVERROR_INVALIDDATA;
/* read header */
get_le16(pb); /* total number of chunks */
frame_rate = get_le16(pb);
get_le16(pb); /* ibm-pc video bios mode */
width = get_le16(pb);
height = get_le16(pb);
url_fseek(pb, length - 10, SEEK_CUR); /* unknown data */
/* video stream */
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
st->codec->codec_type = CODEC_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_MMVIDEO;
st->codec->codec_tag = 0; /* no fourcc */
st->codec->width = width;
st->codec->height = height;
st->codec->palctrl = &mm->palette_control;
av_set_pts_info(st, 64, 1, frame_rate);
/* audio stream */
if (length == MM_HEADER_LEN_AV) {
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_tag = 0; /* no fourcc */
st->codec->codec_id = CODEC_ID_PCM_U8;
st->codec->channels = 1;
st->codec->sample_rate = 8000;
av_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
}
mm->palette_control.palette_changed = 0;
mm->audio_pts = 0;
mm->video_pts = 0;
return 0;
}
static int mm_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
MmDemuxContext *mm = (MmDemuxContext *)s->priv_data;
ByteIOContext *pb = &s->pb;
unsigned char preamble[MM_PREAMBLE_SIZE];
unsigned char pal[MM_PALETTE_SIZE];
unsigned int type, length;
int i;
while(1) {
if (get_buffer(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
return AVERROR_IO;
}
type = LE_16(&preamble[0]);
length = LE_16(&preamble[2]);
switch(type) {
case MM_TYPE_PALETTE :
url_fseek(pb, 4, SEEK_CUR); /* unknown data */
if (get_buffer(pb, pal, MM_PALETTE_SIZE) != MM_PALETTE_SIZE)
return AVERROR_IO;
url_fseek(pb, length - (4 + MM_PALETTE_SIZE), SEEK_CUR);
for (i=0; i<MM_PALETTE_COUNT; i++) {
int r = pal[i*3 + 0];
int g = pal[i*3 + 1];
int b = pal[i*3 + 2];
mm->palette_control.palette[i] = (r << 16) | (g << 8) | (b);
/* repeat palette, where each components is multiplied by four */
mm->palette_control.palette[i+128] = (r << 18) | (g << 10) | (b<<2);
}
mm->palette_control.palette_changed = 1;
break;
case MM_TYPE_INTER :
case MM_TYPE_INTRA :
case MM_TYPE_INTRA_HH :
case MM_TYPE_INTER_HH :
case MM_TYPE_INTRA_HHV :
case MM_TYPE_INTER_HHV :
/* output preamble + data */
if (av_new_packet(pkt, length + MM_PREAMBLE_SIZE))
return AVERROR_NOMEM;
memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
if (get_buffer(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
return AVERROR_IO;
pkt->size = length + MM_PREAMBLE_SIZE;
pkt->stream_index = 0;
pkt->pts = mm->video_pts++;
return 0;
case MM_TYPE_AUDIO :
if (av_get_packet(&s->pb, pkt, length)<0)
return AVERROR_NOMEM;
pkt->size = length;
pkt->stream_index = 1;
pkt->pts = mm->audio_pts++;
return 0;
default :
av_log(NULL, AV_LOG_INFO, "mm: unknown chunk type 0x%x\n", type);
url_fseek(pb, length, SEEK_CUR);
}
}
return 0;
}
static int mm_read_close(AVFormatContext *s)
{
return 0;
}
static AVInputFormat mm_demuxer = {
"mm",
"American Laser Games MM format",
sizeof(MmDemuxContext),
mm_probe,
mm_read_header,
mm_read_packet,
mm_read_close,
};
int mm_init(void)
{
av_register_input_format(&mm_demuxer);
return 0;
}
|
