musix 0.3.5

Music player library for esoteric audio formats (music from C64,Amiga etc)
Documentation 
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


static uint8_t *vgm2s98(uint8_t *ps, uint32_t slen, uint32_t *pdlen)
{
	uint32_t spos = 0x40, dpos = 0x80, psloop, clk, version, dbsize, dbtype,dbwork;
	uint8_t *pd, *dbd = 0;
	size_t dsize = dpos + (slen << 3) + 1;

	if (slen < spos) return 0;

	/* 300%(worst case) */
	pd = (uint8_t *)malloc(dsize);
	if (!pd) return 0;
	XMEMSET(pd, 0, dpos);

	version = GetDwordLE(ps + 0x08);
	SetDwordBE(pd + S98_OFS_MAGIC, S98_MAGIC_V2);
	SetDwordLE(pd + S98_OFS_TIMER_INFO1, 1);
	SetDwordLE(pd + S98_OFS_TIMER_INFO2, SAMPLE_RATE);
	SetDwordLE(pd + S98_OFS_OFSDATA, dpos);
	clk = GetDwordLE(ps + 0x0c);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x00, S98DEVICETYPE_SNG);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x04, clk ? clk : (53693175/15));
	clk = GetDwordLE(ps + 0x10);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x10, S98DEVICETYPE_OPLL);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x14, clk ? clk : (53693175/15));
	if (version >= 0x110) clk = GetDwordLE(ps + 0x2c);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x20, S98DEVICETYPE_OPN2);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x24, clk ? clk : (53693175/7));
	if (version >= 0x110) clk = GetDwordLE(ps + 0x30);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x30, S98DEVICETYPE_OPM);
	SetDwordLE(pd + S98_OFS_DEVICEINFO + 0x34, clk ? clk : 8000000);
	if (version >= 0x150) spos = GetDwordLE(ps + 0x34) + 0x34;

	psloop = GetDwordLE(ps + 0x1c);
	if (psloop) psloop += 0x1c;
	while (spos < slen && ps[spos] != 0x66)
	{
		Uint32 wait = 0;
		if (psloop && psloop == spos) SetDwordLE(pd + S98_OFS_OFSLOOP, dpos);
		switch (ps[spos])
		{
			case 0x4f:	/* GG stereo */
			case 0x50:	/* SNG */
				pd[dpos++] = 0;
				pd[dpos++] = 0x50 - ps[spos++];
				pd[dpos++] = ps[spos++];
				break;
			case 0x51:	/* OPLL */
				spos++;
				pd[dpos++] = 2;
				pd[dpos++] = ps[spos++];
				pd[dpos++] = ps[spos++];
				break;
			case 0x52:	/* OPN2 master */
			case 0x53:	/* OPN2 slave */
				pd[dpos++] = 4 + ps[spos++] - 0x52;
				pd[dpos++] = ps[spos++];
				pd[dpos++] = ps[spos++];
				break;
			case 0x54:	/* OPM */
				spos++;
				pd[dpos++] = 6;
				pd[dpos++] = ps[spos++];
				pd[dpos++] = ps[spos++];
				break;
			case 0x61:
			case 0x62:
			case 0x63:
			{
				switch (ps[spos++])
				{
				  case 0x61:
					wait += GetWordLE(ps + spos);
					spos += 2;
					break;
				  case 0x62:
					wait += 735;
					break;
				  case 0x63:
					wait += 882;
					break;
				  default:
					break;
				}
				break;
			}
			case 0x67:
				dbtype = ps[spos+2];
				dbwork = 0;
				dbsize = GetDwordLE(ps + spos + 3);
				spos += 7;
				dbd = ps + spos;
				spos += dbsize;
				break;
			case 0xe0:
				dbwork = GetDwordLE(ps + spos + 1);
				if (dbwork >= dbsize) dbwork = dbsize - 1;
				spos += 5;
				break;
			default:
			{
				switch(ps[spos] >> 4) {
				  case 3: case 4:
					spos += 2;
					break;
				  case 5:
					spos += 3;
					break;
				  case 7:
					wait += (ps[spos] & 0x0f) + 1;
					spos ++;
					break;
				  case 8:
					wait += (ps[spos] & 0x0f);
					if (dbd && dbtype == 0) {
						pd[dpos++] = 4;
						pd[dpos++] = 0x2a;
						pd[dpos++] = dbd[dbwork++];
						if (dbwork >= dbsize) dbwork = dbsize - 1;
					}
					spos ++;
					break;
				  case 0xa: case 0xb:
					spos += 4;
					break;
				  case 0xc: case 0xd:
					spos += 5;
					break;
				  case 0xe: case 0xf:
					spos += 6;
					break;
				  default:
					spos++;
					break;
				}
			}
		}
		if (wait)
		{
			if (wait == 1)
			{
				pd[dpos++] = 0xff;
			}
			else if (wait == 2) {
				pd[dpos++] = 0xff;
				pd[dpos++] = 0xff;
			}
			else if (wait > 2)
			{ 
				wait -= 2;
				pd[dpos++] = 0xfe;
				while (wait > 0x7f)
				{
					pd[dpos++] = (wait & 0x7f) + 0x80;
					wait >>= 7;
				}
				pd[dpos++] = wait & 0x7f;
			}
			wait = 0;
		}
		if (dpos >= (dsize - 8)) {
			free(pd);
			return 0;
		}
	}
	pd[dpos++] = 0xfd;
	*pdlen = dpos;
	return pd;
}