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mid2s; pull common midi stuff into a lib file, mid2s final fixes

-m is used with when writing to some synths, not sure why this
is necessary, might have missed it in the spec;  dmid on the
other hand doesn't like that

--- a/mid2s.c

+++ b/mid2s.c

@@ -1,315 +1,58 @@

 #include <u.h>

 #include <libc.h>

 #include <bio.h>

+#include "midifile.h"

-enum{

-	Rate = 44100,

-	Nchan = 16,

-	Maxch = 16,	// FIXME: could have more

-	Percch = 9,

-};

+static int magic;

-typedef struct Trk Trk;

-struct Trk{

-	u8int *s;

-	u8int *p;

-	u8int *q;

-	u8int *e;

-	double Δ;

-	double t;

-	int ev;

-	int ended;

-};

-Trk *tr;

-int m2ich[Maxch], i2mch[Maxch], age[Maxch];

-int nch = Nchan, percch = Percch;

-

-int trace;

-int mfmt, ntrk, div = 1, tempo;

-Biobuf *ib;

-

-void *

-emalloc(ulong n)

-{

-	void *p;

-

-	p = mallocz(n, 1);

-	if(p == nil)

-		sysfatal("mallocz: %r");

-	setmalloctag(p, getcallerpc(&n));

-	return p;

-}

-

-Biobuf *

-bfdopen(int fd, int mode)

-{

-	Biobuf *bf;

-

-	bf = Bfdopen(fd, mode);

-	if(bf == nil)

-		sysfatal("bfdopen: %r");

-	Blethal(bf, nil);

-	return bf;

-}

-

-Biobuf *

-bopen(char *file, int mode)

-{

-	int fd;

-

-	fd = open(file, mode);

-	if(fd < 0)

-		sysfatal("bopen: %r");

-	return bfdopen(fd, mode);

-}

-

 void

-bread(void *u, int n)

+samp(uvlong n)

 {

-	if(Bread(ib, u, n) != n)

-		sysfatal("bread: short read");

-}

-

-void

-dprint(char *fmt, ...)

-{

-	char s[256];

-	va_list arg;

-

-	if(!trace)

-		return;

-	va_start(arg, fmt);

-	vseprint(s, s+sizeof s, fmt, arg);

-	va_end(arg);

-	fprint(2, "%s", s);

-}

-

-u8int

-get8(Trk *x)

-{

-	u8int v;

-

-	if(x == nil)

-		Bread(ib, &v, 1);

-	else{

-		if(x->p >= x->e || x->ended)

-			sysfatal("track overflow");

-		v = *x->p++;

-	}

-	dprint("%02ux", v);

-	return v;

-}

-

-u16int

-get16(Trk *x)

-{

-	u16int v;

-

-	v = get8(x) << 8;

-	return v | get8(x);

-}

-

-u32int

-get32(Trk *x)

-{

-	u32int v;

-

-	v = get16(x) << 16;

-	return v | get16(x);

-}

-

-double

-tc(double n)

-{

-	return (n * tempo / div);

-}

-

-void

-skip(Trk *x, int n)

-{

-	while(n-- > 0)

-		get8(x);

-}

-

-int

-getvar(Trk *x)

-{

-	int v, w;

-

-	w = get8(x);

-	v = w & 0x7f;

-	while(w & 0x80){

-		if(v & 0xff000000)

-			sysfatal("invalid variable-length number");

-		v <<= 7;

-		w = get8(x);

-		v |= w & 0x7f;

-	}

-	return v;

-}

-

-// FIXME: common midi.c shit (midilib.c? midifile?)

-void

-samp(double n)

-{

 	double Δt;

 	long s;

-	static double t0, t1;

+	static double t0;

 	if(t0 == 0.0)

 		t0 = nsec();

-	t1 = t0 + n * 1000 * tempo / div;

-	t0 = t1;

-	Δt = t1 - nsec();

+	t0 += n * 1000 * tempo / div;

+	Δt = t0 - nsec();

 	s = floor(Δt / 1000000);

 	if(s > 0)

 		sleep(s);

 }

-int

-mapinst(Trk *, int c, int e)

+/* set delay to 0, and translate running status: the receiver

+ * only sees one track whereas running status is a property of

+ * each track (stream); don't send EOT for the same reason */

+static void

+eat(Trk *x)

 {

-	int i, m, a;

+	int e, n;

+	uchar u[16], *p, *q;

+	Msg msg;

-	i = m2ich[c];

-	if(c == 9)

-		i = percch;

-	else if(e >> 4 != 0x9){

-		if(e >> 4 == 0x8 && i >= 0){

-			i2mch[i] = -1;

-			m2ich[c] = -1;

-		}

-		return e;

-	}else if(i < 0){

-		for(i=0; i<nch; i++){

-			if(i == percch)

-				continue;

-			if(i2mch[i] < 0)

-				break;

-		}

-		if(i == nch){

-			for(m=i=a=0; i<nch; i++){

-				if(i == percch)

-					continue;

-				if(age[i] > age[m]){

-					m = i;

-					a = age[i];

-				}

-			}

-			if(a < 100){

-				fprint(2, "could not remap %d\n", c);

-				return e;

-			}

-			i = m;

-			fprint(2, "remapped %d → %d\n", c, i);

-		}

+	q = u + 1;

+	e = nextevent(x);

+	*q++ = e;

+	p = x->p;

+	translate(x, e, &msg);

+	if(msg.type == Ceot)

+		return;

+	u[0] = magic ? e >> 4 | (e & 0xf) << 4 : 0;

+	n = x->p - p;

+	if(msg.type == Csysex || n > nelem(u) - (q - u)){

+		write(1, u, q - u);

+		write(1, p, n);

+	}else{

+		memcpy(q, p, n);

+		write(1, u, n + (q - u));

 	}

-	age[i] = 0;

-	m2ich[c] = i;

-	i2mch[i] = c;

-	return e & ~(Nchan-1) | i;

 }

-int

-ev(Trk *x, vlong)

-{

-	int e, n, m;

-

-	x->q = x->p - 1;

-	dprint(" [%zd] ", x - tr);

-	e = get8(x);

-	if((e & 0x80) == 0){

-		x->p--;

-		e = x->ev;

-		x->q--;

-		x->q[1] = e;

-		if((e & 0x80) == 0)

-			sysfatal("invalid event");

-	}else

-		x->ev = e;

-	dprint("(%02ux) ", e);

-

-	e = mapinst(x, e & 15, e);

-

-	n = get8(x);

-	if((e & 15) == percch){

-		if(n < 36)

-			n += 36 - n;

-	}

-	switch(e >> 4){

-	case 0x8: get8(x); break;

-	case 0x9: get8(x); break;

-	case 0xb: get8(x); break;

-	case 0xc: break;

-	case 0xe: get8(x); break;

-	case 0xf:

-		if((e & 0xf) == 0){

-			while(get8(x) != 0xf7)

-				;

-			break;

-		}

-		m = get8(x);

-		switch(n){

-		case 0x2f: dprint(" -- so long!\n"); return -1;

-		case 0x51: tempo = get16(x) << 8; tempo |= get8(x); break;

-		default: skip(x, m);

-		}

-		break;

-	case 0xa: get8(x); break;

-	case 0xd: get8(x); break;

-	default: sysfatal("invalid event %#ux\n", e >> 4);

-	}

-	dprint("\n");

-	if(x->p > x->q){

-		x->q[1] = e;

-		x->q[0] = x->q[1] >> 4 | (x->q[1] & 0xff) << 4;

-		write(1, x->q, x->p - x->q);

-		x->q = x->p;

-	}

-	return 0;

-}

-

 void

-readmid(char *file)

-{

-	u32int n, z;

-	uchar *s;

-	Trk *x;

-

-	ib = file != nil ? bopen(file, OREAD) : bfdopen(0, OREAD);

-	if(get32(nil) != 0x4d546864 || get32(nil) != 6)

-		sysfatal("invalid header");

-	mfmt = get16(nil);

-	ntrk = get16(nil);

-	if(ntrk == 1)

-		mfmt = 0;

-	if(mfmt < 0 || mfmt > 1)

-		sysfatal("unsupported format %d", mfmt);

-	div = get16(nil);

-	tr = emalloc(ntrk * sizeof *tr);

-	for(x=tr, z=-1UL; x<tr+ntrk; x++){

-		if(get32(nil) != 0x4d54726b)

-			sysfatal("invalid track");

-		n = get32(nil);

-		s = emalloc(n);

-		bread(s, n);

-		x->s = s;

-		x->p = s;

-		x->q = x->p;

-		x->e = s + n;

-		x->Δ = getvar(x);	/* prearm */

-		if(x->Δ < z)

-			z = x->Δ;

-	}

-	for(x=tr; x<tr+ntrk; x++)

-		x->Δ -= z;

-	Bterm(ib);

-}

-

-void

 usage(void)

 {

-	fprint(2, "usage: %s [-D] [-c nch] [-p percch] [mid]\n", argv0);

+	fprint(2, "usage: %s [-D] [mid]\n", argv0);

 	exits("usage");

 }

@@ -316,31 +59,17 @@

 void

 main(int argc, char **argv)

 {

-	int i, c, end, debug;

+	int end;

+	uchar eot[] = {0x00, 0xff, 0x2f, 0x00};

 	Trk *x;

-	debug = 0;

 	ARGBEGIN{

-	case 'D': debug = 1; break;

-	case 'c':

-		nch = atoi(EARGF(usage()));

-		break;

-	case 'p':

-		percch = atoi(EARGF(usage()));

-		break;

+	case 'D': trace = 1; break;

+	case 'm': magic = 1; break;	/* FIXME: investigate more */

 	default: usage();

 	}ARGEND

-	if(nch <= 0 || nch > Maxch)

-		usage();

-	if(percch <= 0 || percch > nch)

-		usage();

-	readmid(*argv);

-	tempo = 500000;

-	trace = debug;

-	for(i=0; i<nelem(m2ich); i++){

-		m2ich[i] = i2mch[i] = -1;

-		age[i] = -1UL;

-	}

+	if(readmid(*argv) < 0)

+		sysfatal("readmid: %r");

 	for(;;){

 		end = 1;

 		for(x=tr; x<tr+ntrk; x++){

@@ -349,33 +78,16 @@

 			end = 0;

 			x->Δ--;

 			while(x->Δ <= 0){

-				if(x->ended = ev(x, 0)){

-					c = x - tr;

-					i = m2ich[c];

-					if(i >= 0){

-						i2mch[i] = -1;

-						m2ich[c] = -1;

-					}

+				eat(x);

+				if(x->ended)

 					break;

-				}

 				x->Δ = getvar(x);

 			}

 		}

-		if(end){

-			write(1, tr[0].q, tr[0].p - tr[0].q);

+		if(end)

 			break;

-		}

 		samp(1);

-		for(i=0; i<nch; i++){

-			if(i2mch[i] < 0)

-				continue;

-			age[i]++;

-			if(age[i] > 10000){

-				fprint(2, "reset %d\n", i2mch[i]);

-				m2ich[i2mch[i]] = -1;

-				i2mch[i] = -1;

-			}

-		}

 	}

+	write(1, eot, sizeof eot);

 	exits(nil);

 }

--- /dev/null

+++ b/midifile.c

@@ -1,0 +1,320 @@

+#include <u.h>

+#include <libc.h>

+#include <bio.h>

+#include "midifile.h"

+

+Trk *tr;

+int mfmt, ntrk, div = 1, tempo = 500000;

+int trace, stream;

+vlong tic;

+Biobuf *ib;

+

+void *

+emalloc(ulong n)

+{

+	void *p;

+

+	p = mallocz(n, 1);

+	if(p == nil)

+		sysfatal("mallocz: %r");

+	setmalloctag(p, getcallerpc(&n));

+	return p;

+}

+

+void

+dprint(char *fmt, ...)

+{

+	char s[256];

+	va_list arg;

+

+	if(!trace)

+		return;

+	va_start(arg, fmt);

+	vseprint(s, s+sizeof s, fmt, arg);

+	va_end(arg);

+	fprint(2, "%s", s);

+}

+

+Biobuf *

+bfdopen(int fd, int mode)

+{

+	Biobuf *bf;

+

+	bf = Bfdopen(fd, mode);

+	if(bf == nil)

+		sysfatal("bfdopen: %r");

+	Blethal(bf, nil);

+	return bf;

+}

+

+Biobuf *

+bopen(char *file, int mode)

+{

+	int fd;

+

+	fd = open(file, mode);

+	if(fd < 0)

+		sysfatal("bopen: %r");

+	return bfdopen(fd, mode);

+}

+

+void

+bread(void *u, int n)

+{

+	if(Bread(ib, u, n) != n)

+		sysfatal("bread: short read");

+}

+

+u8int

+get8(Trk *x)

+{

+	u8int v;

+

+	if(x == nil || x->p == nil || x->e == nil)

+		Bread(ib, &v, 1);

+	else{

+		if(x->p >= x->e || x->ended)

+			sysfatal("track overflow");

+		v = *x->p++;

+	}

+	return v;

+}

+

+u16int

+get16(Trk *x)

+{

+	u16int v;

+

+	v = get8(x) << 8;

+	return v | get8(x);

+}

+

+u32int

+get32(Trk *x)

+{

+	u32int v;

+

+	v = get16(x) << 16;

+	return v | get16(x);

+}

+

+u8int

+peekbyte(Trk *x)

+{

+	return *x->p;

+}

+

+u32int

+peekvar(Trk *x)

+{

+	uchar *p;

+	uint v;

+

+	p = x->p;

+	v = getvar(x);

+	x->p = p;

+	return v;

+}

+

+void

+skip(Trk *x, int n)

+{

+	while(n-- > 0)

+		get8(x);

+}

+

+int

+getvar(Trk *x)

+{

+	int v, w;

+

+	w = get8(x);

+	v = w & 0x7f;

+	while(w & 0x80){

+		if(v & 0xff000000)

+			sysfatal("invalid variable-length number");

+		v <<= 7;

+		w = get8(x);

+		v |= w & 0x7f;

+	}

+	return v;

+}

+

+double

+tc(double n)

+{

+	return (n * tempo * Rate / div) / 1e6;

+}

+

+int

+nextevent(Trk *x)

+{

+	int e;

+

+	x->prev = x->p;

+	e = get8(x);

+	if((e & 0x80) == 0){

+		if(x->p != nil){

+			x->p--;

+			x->prev--;

+		}

+		e = x->ev;

+		if((e & 0x80) == 0)

+			sysfatal("invalid event %#ux", e);

+	}else

+		x->ev = e;

+	return e;

+}

+

+/* FIXME: use midump's implementation to make this not suck */

+static void

+setmsg(Msg *m, int chan, int type, int arg1, int arg2)

+{

+	m->chan = chan;

+	m->type = type;

+	m->arg1 = arg1;

+	m->arg2 = arg2;

+}

+void

+translate(Trk *x, int e, Msg *msg)

+{

+	int c, n, m, type;

+	uchar *p;

+

+	c = e & 0xf;

+	dprint("ch%02d ", c);

+	n = get8(x);

+	m = -1;

+	type = Cunknown;

+	switch(e >> 4){

+	case 0x8:

+		m = get8(x);

+		dprint("note off\t%02ux\taftertouch\t%02ux", n, m);

+		type = Cnoteoff;

+		break;

+	case 0x9:

+		m = get8(x);

+		dprint("note on\t%02ux\tvelocity\t%02ux", n, m);

+		type = Cnoteon;

+		break;

+	case 0xb:

+		m = get8(x);

+		dprint("control change: ");

+		switch(n){

+		case 0x00:

+			dprint("bank select msb\t%02ux", m);

+			type = Cbankmsb;

+			break;

+		case 0x07:

+			dprint("channel volume\t%02ux", m);

+			type = Cchanvol;

+			break;

+		case 0x0a:

+			dprint("pan\t%02ux", m);

+			type = Cpan;

+			break;

+		default:

+			dprint("unknown controller %.4ux", n);

+			break;

+		}

+		break;

+	case 0xc:

+		dprint("program change\t%02ux", n);

+		type = Cprogram;

+		break;

+	case 0xe:

+		n = (get8(x) << 7 | n) - 0x4000 / 2;

+		dprint("pitch bend\t%02x", n);

+		type = Cpitchbend;

+		break;

+	case 0xf:

+		dprint("sysex:\t");

+		if((e & 0xf) == 0){

+			m = 0;

+			while(get8(x) != 0xf7)

+				m++;

+			fprint(2, "sysex n %d m %d\n", n, m);

+			type = Csysex;

+			break;

+		}

+		m = get8(x);

+		switch(n){

+		case 0x2f:

+			dprint("... so long!");

+			x->ended = 1;

+			type = Ceot;

+			break;

+		case 0x51:

+			tempo = get16(x) << 8;

+			tempo |= get8(x);

+			dprint("tempo change\t%d", tempo);

+			type = Ctempo;

+			break;

+		default:

+			dprint("skipping unhandled event %02ux", n);

+			skip(x, m);

+			break;

+		}

+		break;

+	case 0xa:

+		m = get8(x);

+		dprint("polyphonic key pressure/aftertouch\t%02ux\t%02ux", n, m);

+		type = Ckeyafter;

+		break;

+	case 0xd:

+		m = get8(x);

+		dprint("channel pressure/aftertouch\t%02ux\t%02ux", n, m);

+		type = Cchanafter;

+		break;

+	default: sysfatal("invalid event %#ux", e >> 4);

+	}

+	setmsg(msg, c, type, n, m);

+	dprint("\t[");

+	for(p=x->prev; p<x->p; p++)

+		dprint("%02ux", *p);

+	dprint("]\n");

+}

+

+int

+readmid(char *file)

+{

+	u32int n, z;

+	uchar *s;

+	Trk *x;

+

+	ib = file != nil ? bopen(file, OREAD) : bfdopen(0, OREAD);

+	if(get32(nil) != 0x4d546864 || get32(nil) != 6){

+		werrstr("invalid header");

+		return -1;

+	}

+	mfmt = get16(nil);

+	ntrk = get16(nil);

+	if(ntrk == 1)

+		mfmt = 0;

+	if(mfmt < 0 || mfmt > 1){

+		werrstr("unsupported format %d", mfmt);

+		return -1;

+	}

+	div = get16(nil);

+	tr = emalloc(ntrk * sizeof *tr);

+	for(x=tr, z=-1UL; x<tr+ntrk; x++){

+		if(get32(nil) != 0x4d54726b){

+			werrstr("invalid track");

+			return -1;

+		}

+		n = get32(nil);

+		x->s = emalloc(n+1);

+		bread(x->s, n);

+		x->p = x->s;

+		x->prev = x->s;

+		x->e = x->s + n;

+		x->Δ = getvar(x);	/* prearm */

+		if(x->Δ < z)

+			z = x->Δ;

+	}

+	for(x=tr; x<tr+ntrk; x++)

+		x->Δ -= z;

+	Bterm(ib);

+	ib = nil;

+	return 0;

+}

--- /dev/null

+++ b/midifile.h

@@ -1,0 +1,60 @@

+typedef struct Msg Msg;

+typedef struct Trk Trk;

+

+enum{

+	Rate = 44100,

+	Ninst = 128 + 81-35+1,

+	Nchan = 16,

+	Percch = 9,

+};

+

+struct Msg{

+	int type;

+	int chan;

+	int arg1;

+	int arg2;

+};

+// FIXME: naming

+// FIXME: hicucps playing when there are sysex etc events (-s)

+struct Trk{

+	u8int *s;

+	u8int *prev;

+	u8int *p;

+	u8int *e;

+	double Δ;

+	double t;

+	int ev;

+	int ended;

+};

+extern Trk *tr;

+

+enum{

+	Cnoteoff,

+	Cnoteon,

+	Cbankmsb,

+	Cchanvol,

+	Cpan,

+	Cprogram,

+	Cpitchbend,

+	Ceot,

+	Ctempo,

+	Ckeyafter,

+	Cchanafter,

+	Csysex,

+	Cunknown,

+};

+

+extern int mfmt, ntrk, div, tempo;

+extern int trace, stream;

+

+void*	emalloc(ulong);

+int	readmid(char*);

+void	dprint(char*, ...);

+void	samp(uvlong);

+u32int	peekvar(Trk*);

+u8int	peekbyte(Trk*);

+int	nextevent(Trk*);

+void	translate(Trk*, int, Msg*);

+int	getvar(Trk*);

+

+#pragma	varargck	argpos	dprint	1

--- a/mkfile

+++ b/mkfile

@@ -22,3 +22,12 @@

 (calc).c:R:	\1.tab.c

 	mv $stem1.tab.c $stem1.c

+

+$O.mid2s: mid2s.$O midifile.$O

+	$LD $LDFLAGS -o $target $prereq

+

+$O.s2mid: s2mid.$O midifile.$O

+	$LD $LDFLAGS -o $target $prereq

+

+$O.midump: midump.$O midifile.$O

+	$LD $LDFLAGS -o $target $prereq