ref: 297bf25f612d2dde0d28d7feaae0ea381be114a7
parent: 009bec07521287ebfc9f4dcfddac18d8f27f1fb9
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Sun Feb 26 14:23:52 EST 2017
add games/mus midi converter (by qu7uux)
--- /dev/null
+++ b/sys/man/1/mus
@@ -1,0 +1,25 @@
+.TH MUS 1
+.SH NAME
+mus \- MUS to MIDI converter
+.SH SYNOPSIS
+.B games/mus
+[
+.I musfile
+]
+.SH DESCRIPTION
+The MUS format is a simplified MIDI music format used in
+.IR doom (1)
+and several related games.
+.PP
+.I Mus
+decodes MIDI music encoded in MUS format, either from
+.B musfile
+or from standard input, and produces a MIDI format file on standard output.
+.SH "SEE ALSO"
+.IR doom (1) ,
+.IR midi (1)
+.SH SOURCE
+.B /sys/src/games/mus.c
+.SH HISTORY
+.I Mus
+appeared first for 9front (September, 2015).
--- a/sys/src/games/mkfile
+++ b/sys/src/games/mkfile
@@ -10,6 +10,7 @@
life\
memo\
mole\
+ mus\
glendy\
packet\
mandel\
--- /dev/null
+++ b/sys/src/games/mus.c
@@ -1,0 +1,267 @@
+#include <u.h>
+#include <libc.h>
+
+typedef struct Trk Trk;
+typedef struct Ch Ch;
+
+struct Ch{+ uchar n[128];
+ uchar pitch;
+ uchar ctl[10];
+};
+struct Trk{+ u32int len;
+ uchar *dat;
+ uchar *p;
+ uchar *end;
+ Ch c[16];
+ long delay;
+ int done;
+};
+Trk t;
+uchar *mcmd, *mp, *me;
+int fd;
+
+#define PBIT16(p,v) (p)[0]=(v);(p)[1]=(v)>>8
+#define BBIT32(p,v) (p)[3]=(v);(p)[2]=(v)>>8;(p)[1]=(v)>>16;(p)[0]=(v)>>24
+
+void
+eread(int fd, void *u, long n)
+{+ if(readn(fd, u, n) != n)
+ sysfatal("readn: %r");+}
+
+uchar
+r8(void)
+{+ return *t.p++;
+}
+
+u32int
+delay(void)
+{+ u32int t;
+ uchar v;
+
+ t = 0;
+ do{+ v = r8();
+ t = t << 7 | v & 0x7f;
+ *mp++ = v;
+ }while(v & 0x80);
+ return t;
+}
+
+void
+putcmd(uchar *cmd, int n)
+{+ if(mp + n >= me){+ me += 8192;
+ mcmd = realloc(mcmd, me - mcmd);
+ if(mcmd == nil)
+ sysfatal("realloc: %r");+ }
+ memcpy(mp, cmd, n);
+ mp += n;
+}
+
+void
+ev(void)
+{+ uchar e, v;
+ Ch *c;
+ uchar cmd[3], *p;
+
+ e = r8();
+ c = &t.c[e & 15];
+ p = cmd;
+ switch(e >> 4 & 7){+ case 0:
+ v = r8() & 0x7f;
+ c->n[v] = 0;
+ *p++ = e | 0x80;
+ *p++ = v;
+ *p++ = 0x40;
+ break;
+ case 1:
+ v = r8();
+ if(v & 0x80){+ c->n[v] = r8() & 0x7f;
+ c->ctl[3] = c->n[v];
+ }else
+ c->n[v] = c->ctl[3];
+ *p++ = e | 0x80;
+ *p++ = v & 0x7f;
+ *p++ = c->n[v];
+ break;
+ case 2:
+ c->pitch = r8();
+ *p++ = e | 0xc0;
+ PBIT16(p, c->pitch << 7 & 0x7f7f);
+ p += 2;
+ break;
+ case 3:
+ v = r8();
+ *p++ = 0xb | e & 15;
+ switch(v){+ case 10:
+ for(v=0; v<128; v++)
+ c->n[v] = 0;
+ *p++ = 0x78;
+ break;
+ case 11:
+ for(v=0; v<128; v++)
+ c->n[v] = 0;
+ *p++ = 0x7b;
+ break;
+ case 12:
+ *p++ = 0x7e;
+ break;
+ case 13:
+ *p++ = 0x7f;
+ break;
+ case 14:
+ memset(c->n, 0, sizeof c->n);
+ memset(c->ctl, 0, sizeof c->ctl);
+ c->ctl[3] = 0x7f;
+ c->ctl[4] = 64;
+ if((e & 15) == 15)
+ c->pitch = 60;
+ else
+ c->pitch = 128;
+ *p++ = 0x79;
+ break;
+ default:
+ sysfatal("unknown system event %ux\n", v);+ }
+ *p++ = 0;
+ break;
+ case 4:
+ v = r8();
+ if(v > 9)
+ sysfatal("unknown controller %ux\n", v);+ c->ctl[v] = r8() & 0x7f;
+ *p++ = 0xb0 | e & 15;
+ switch(v){+ case 1: *p++ = 0x00; break;
+ case 2: *p++ = 0x01; break;
+ case 3: *p++ = 0x07; break;
+ case 4: *p++ = 0x0a; break;
+ case 5: *p++ = 0x0b; break;
+ case 6: *p++ = 0x5b; break;
+ case 7: *p++ = 0x5d; break;
+ case 8: *p++ = 0x40; break;
+ case 9: *p++ = 0x43; break;
+ }
+ *p++ = c->ctl[v];
+ if(v == 0)
+ cmd[0] += 0x10;
+ break;
+ case 6:
+ *p++ = 0xff;
+ *p++ = 0x2f;
+ e = 0;
+ t.done++;
+ break;
+ default:
+ sysfatal("unknown event %ux\n", e >> 4 & 7);+ }
+ if((e & 15) == 9)
+ cmd[0] += 1;
+ if((e & 15) == 15)
+ cmd[0] &= ~6;
+ putcmd(cmd, p-cmd);
+ t.delay = 0;
+ if(e & 0x80)
+ t.delay = delay();
+ else
+ *mp++ = 0;
+}
+
+void
+reset(void)
+{+ Ch *c;
+
+ c = t.c;
+ while(c < t.c + nelem(t.c)){+ c->pitch = 128;
+ c->ctl[3] = 0x7f;
+ c->ctl[4] = 64;
+ c++;
+ }
+ t.c[15].pitch = 60;
+ mcmd = mallocz(t.len * 2, 1);
+ if(mcmd == nil)
+ sysfatal("mallocz: %r");+ mp = mcmd;
+ me = mcmd + t.len * 2;
+}
+
+void
+barf(void)
+{+ static uchar hdr[] = {+ 'M', 'T', 'h', 'd',
+ 0x00, 0x00, 0x00, 0x06,
+ 0x00, 0x00,
+ 0x00, 0x01,
+ 0x01, 0x01,
+ 'M', 'T', 'r', 'k',
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0xb0, 0x07, 0x7f,
+ 0x00, 0xb1, 0x07, 0x7f,
+ 0x00, 0xb2, 0x07, 0x7f,
+ 0x00, 0xb3, 0x07, 0x7f,
+ 0x00, 0xb4, 0x07, 0x7f,
+ 0x00, 0xb5, 0x07, 0x7f,
+ 0x00, 0xb6, 0x07, 0x7f,
+ 0x00, 0xb7, 0x07, 0x7f,
+ 0x00, 0xb8, 0x07, 0x7f,
+ 0x00, 0xb9, 0x07, 0x7f,
+ 0x00, 0xba, 0x07, 0x7f,
+ 0x00, 0xff, 0x51, 0x03, 0x1b, 0x8a, 0x06,
+ 0x00
+ };
+ int n;
+
+ n = sizeof(hdr) - 22 + mp - mcmd;
+ BBIT32(hdr + 18, n);
+ write(1, hdr, sizeof hdr);
+ write(1, mcmd, mp - mcmd);
+}
+
+void
+main(int argc, char *argv[])
+{+ int n, ofs;
+ uchar s[8], b[1024];
+
+ if(argc > 1){+ fd = open(argv[1], OREAD);
+ if(fd < 0)
+ sysfatal("open: %r");+ }
+ eread(fd, s, sizeof s);
+ if(memcmp(s, "MUS\x1a", 4) != 0)
+ sysfatal("invalid mus file: %r");+ t.len = s[5] << 8 | s[4];
+ ofs = (s[7] << 8 | s[6]) - 8;
+ while(ofs > 0){+ n = ofs > sizeof b ? sizeof b : ofs;
+ eread(fd, b, n);
+ ofs -= n;
+ }
+ t.dat = malloc(t.len);
+ if(t.dat == nil)
+ sysfatal("malloc: %r");+ t.p = t.dat;
+ t.end = t.dat + t.len;
+ eread(fd, t.dat, t.len);
+ reset();
+ while(!t.done && t.p < t.end)
+ ev();
+ barf();
+ exits(nil);
+}