Statistics
| Branch: | Revision:

ffmpeg / libavformat / mm.c @ 57060f89

History | View | Annotate | Download (6.3 KB)

1 4e114829 Mike Melanson
/*
2
 * American Laser Games MM Format Demuxer
3
 * Copyright (c) 2006 Peter Ross
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
16
 * License along with this library; if not, write to the Free Software
17 538389c9 Diego Biurrun
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18 4e114829 Mike Melanson
 */
19
20
/**
21
 * @file mm.c
22
 * American Laser Games MM Format Demuxer
23
 * by Peter Ross (suxen_drol at hotmail dot com)
24
 *
25
 * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
26
 * including Mad Dog McCree and Crime Patrol.
27
 *
28
 * Technical details here:
29
 *  http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
30
 */
31
32
#include "avformat.h"
33
34
#define MM_PREAMBLE_SIZE    6
35
36
#define MM_TYPE_HEADER      0x0
37
#define MM_TYPE_INTER       0x5
38
#define MM_TYPE_INTRA       0x8
39
#define MM_TYPE_INTRA_HH    0xc
40
#define MM_TYPE_INTER_HH    0xd
41
#define MM_TYPE_INTRA_HHV   0xe
42
#define MM_TYPE_INTER_HHV   0xf
43
#define MM_TYPE_AUDIO       0x15
44
#define MM_TYPE_PALETTE     0x31
45
46
#define MM_HEADER_LEN_V     0x16    /* video only */
47
#define MM_HEADER_LEN_AV    0x18    /* video + audio */
48
49
#define MM_PALETTE_COUNT    128
50
#define MM_PALETTE_SIZE     (MM_PALETTE_COUNT*3)
51
52
typedef struct {
53
  AVPaletteControl palette_control;
54
  unsigned int audio_pts, video_pts;
55
} MmDemuxContext;
56
57
static int mm_probe(AVProbeData *p)
58
{
59
    /* the first chunk is always the header */
60
    if (p->buf_size < MM_PREAMBLE_SIZE)
61
        return 0;
62
    if (LE_16(&p->buf[0]) != MM_TYPE_HEADER)
63
        return 0;
64
    if (LE_32(&p->buf[2]) != MM_HEADER_LEN_V && LE_32(&p->buf[2]) != MM_HEADER_LEN_AV)
65
        return 0;
66
67
    /* only return half certainty since this check is a bit sketchy */
68
    return AVPROBE_SCORE_MAX / 2;
69
}
70
71
static int mm_read_header(AVFormatContext *s,
72
                           AVFormatParameters *ap)
73
{
74
    MmDemuxContext *mm = (MmDemuxContext *)s->priv_data;
75
    ByteIOContext *pb = &s->pb;
76
    AVStream *st;
77
78
    unsigned int type, length;
79
    unsigned int frame_rate, width, height;
80
81
    type = get_le16(pb);
82
    length = get_le32(pb);
83
84
    if (type != MM_TYPE_HEADER)
85
        return AVERROR_INVALIDDATA;
86
87
    /* read header */
88
    get_le16(pb);   /* total number of chunks */
89
    frame_rate = get_le16(pb);
90
    get_le16(pb);   /* ibm-pc video bios mode */
91
    width = get_le16(pb);
92
    height = get_le16(pb);
93
    url_fseek(pb, length - 10, SEEK_CUR);  /* unknown data */
94
95
    /* video stream */
96
    st = av_new_stream(s, 0);
97
    if (!st)
98
        return AVERROR_NOMEM;
99
    st->codec->codec_type = CODEC_TYPE_VIDEO;
100
    st->codec->codec_id = CODEC_ID_MMVIDEO;
101
    st->codec->codec_tag = 0;  /* no fourcc */
102
    st->codec->width = width;
103
    st->codec->height = height;
104
    st->codec->palctrl = &mm->palette_control;
105
    av_set_pts_info(st, 64, 1, frame_rate);
106
107
    /* audio stream */
108
    if (length == MM_HEADER_LEN_AV) {
109
        st = av_new_stream(s, 0);
110
        if (!st)
111
            return AVERROR_NOMEM;
112
        st->codec->codec_type = CODEC_TYPE_AUDIO;
113
        st->codec->codec_tag = 0; /* no fourcc */
114
        st->codec->codec_id = CODEC_ID_PCM_U8;
115
        st->codec->channels = 1;
116
        st->codec->sample_rate = 8000;
117
        av_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
118
    }
119
120
    mm->palette_control.palette_changed = 0;
121
    mm->audio_pts = 0;
122
    mm->video_pts = 0;
123
    return 0;
124
}
125
126
static int mm_read_packet(AVFormatContext *s,
127
                           AVPacket *pkt)
128
{
129
    MmDemuxContext *mm = (MmDemuxContext *)s->priv_data;
130
    ByteIOContext *pb = &s->pb;
131
    unsigned char preamble[MM_PREAMBLE_SIZE];
132
    unsigned char pal[MM_PALETTE_SIZE];
133
    unsigned int type, length;
134
    int i;
135
136
    while(1) {
137
138
        if (get_buffer(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
139
            return AVERROR_IO;
140
        }
141
142
        type = LE_16(&preamble[0]);
143
        length = LE_16(&preamble[2]);
144
145
        switch(type) {
146
        case MM_TYPE_PALETTE :
147
            url_fseek(pb, 4, SEEK_CUR);  /* unknown data */
148
            if (get_buffer(pb, pal, MM_PALETTE_SIZE) != MM_PALETTE_SIZE)
149
                return AVERROR_IO;
150
            url_fseek(pb, length - (4 + MM_PALETTE_SIZE), SEEK_CUR);
151
152
            for (i=0; i<MM_PALETTE_COUNT; i++) {
153
                int r = pal[i*3 + 0];
154
                int g = pal[i*3 + 1];
155
                int b = pal[i*3 + 2];
156
                mm->palette_control.palette[i] = (r << 16) | (g << 8) | (b);
157
                /* repeat palette, where each components is multiplied by four */
158
                mm->palette_control.palette[i+128] = (r << 18) | (g << 10) | (b<<2);
159
            }
160
            mm->palette_control.palette_changed = 1;
161
            break;
162
163
        case MM_TYPE_INTER :
164
        case MM_TYPE_INTRA :
165
        case MM_TYPE_INTRA_HH :
166
        case MM_TYPE_INTER_HH :
167
        case MM_TYPE_INTRA_HHV :
168
        case MM_TYPE_INTER_HHV :
169
            /* output preamble + data */
170
            if (av_new_packet(pkt, length + MM_PREAMBLE_SIZE))
171
                return AVERROR_NOMEM;
172
            memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
173
            if (get_buffer(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
174
                return AVERROR_IO;
175
            pkt->size = length + MM_PREAMBLE_SIZE;
176
            pkt->stream_index = 0;
177
            pkt->pts = mm->video_pts++;
178
            return 0;
179
180
        case MM_TYPE_AUDIO :
181
            if (av_get_packet(&s->pb, pkt, length)<0)
182
                return AVERROR_NOMEM;
183
            pkt->size = length;
184
            pkt->stream_index = 1;
185
            pkt->pts = mm->audio_pts++;
186
            return 0;
187
188
        default :
189
            av_log(NULL, AV_LOG_INFO, "mm: unknown chunk type 0x%x\n", type);
190
            url_fseek(pb, length, SEEK_CUR);
191
        }
192
    }
193
194
    return 0;
195
}
196
197
static int mm_read_close(AVFormatContext *s)
198
{
199
    return 0;
200
}
201
202 ff70e601 Måns Rullgård
AVInputFormat mm_demuxer = {
203 4e114829 Mike Melanson
    "mm",
204
    "American Laser Games MM format",
205
    sizeof(MmDemuxContext),
206
    mm_probe,
207
    mm_read_header,
208
    mm_read_packet,
209
    mm_read_close,
210
};