shithub: riscv

Info  •  Files  •  Log  •  Branches

midi: ignore bends, allow piping from stdin and to stdout, write in chunks from within sample loop (thanks qu7uux)

--- a/sys/src/games/midi.c

+++ b/sys/src/games/midi.c

@@ -16,6 +16,7 @@

 int fd, ofd, div, tempo = 500000, ntrack;

 uvlong T;

 int freq[128];

+uchar out[8192], *outp = out;

 void *

 emallocz(int size)

@@ -110,8 +111,7 @@

 void

 run(uvlong n)

 {

-	int samp, j, k, l, no[128];

-	uchar *s;

+	int samp, j, k, no[128];

 	int t, f;

 	short u;

 	Tracker *x;

@@ -127,8 +127,7 @@

 			for(k = 0; k < 128; k++)

 				no[k] += x->notes[j][k];

 	}

-	s = emallocz(samp * 4);

-	for(l = 0; l < samp; l++){

+	while(samp--){

 		t = 0;

 		for(k = 0; k < 128; k++){

 			f = (T % freq[k]) >= freq[k]/2 ? 1 : 0;

@@ -135,12 +134,15 @@

 			t += f * no[k];

 		}

 		u = t*10;

-		s[4 * l] = s[4 * l + 2] = u;

-		s[4 * l + 1] = s[4 * l + 3] = u >> 8;

+		outp[0] = outp[2] = u;

+		outp[1] = outp[3] = u >> 8;

+		outp += 4;

+		if(outp == out + sizeof out){

+			write(ofd, out, sizeof out);

+			outp = out;

+		}

 		T++;

 	}

-	write(ofd, s, samp * 4);

-	free(s);

 }

 void

@@ -175,6 +177,9 @@

 	case 0xC:

 		get8(src);

 		break;

+	case 0xE:

+		get16(src);

+		break;

 	case 0xF:

 		t = get8(src);

 		n = get8(src);

@@ -187,11 +192,11 @@

 			tempo |= get8(src);

 			break;

 		case 5:

-			write(1, src->data, n);

+			write(2, src->data, n);

 			skip(src, n);

 			break;

 		default:

-			print("unknown meta event type %.2x\n", t);

+			fprint(2, "unknown meta event type %.2x\n", t);

 		case 3: case 1: case 2: case 0x58: case 0x59: case 0x21:

 			skip(src, n);

 		}

@@ -208,14 +213,17 @@

 	uvlong t, mint;

 	Tracker *x, *minx;

-	if(argc != 2)

-		sysfatal("invalid arguments");

-	fd = open(argv[1], OREAD);

-	if(fd < 0)

+	ARGBEGIN{

+	case 'c':

+		ofd = 1;

+		break;

+	}ARGEND;

+	if(*argv != nil)

+		fd = open(*argv, OREAD);

+	if(ofd == 0)

+		ofd = open("/dev/audio", OWRITE);

+	if(fd < 0 || ofd < 0)

 		sysfatal("open: %r");

-	ofd = open("/dev/audio", OWRITE);

-	if(ofd < 0)

-		sysfatal("ofd: %r");

 	if(get32(nil) != 0x4D546864 || get32(nil) != 6)

 		sysfatal("invalid file header");

 	get16(nil);

@@ -227,7 +235,7 @@

 			sysfatal("invalid track header");

 		size = get32(nil);

 		tr[i].data = emallocz(size);

-		read(fd, tr[i].data, size);

+		readn(fd, tr[i].data, size);

 	}

 	for(i = 0; i < 128; i++)

 		freq[i] = SAMPLE / (440 * pow(1.05946, i - 69));

@@ -243,8 +251,10 @@

 				minx = x;

 			}

 		}

-		if(minx == nil)

+		if(minx == nil){

+			write(ofd, out, outp - out);

 			exits(nil);

+		}

 		readevent(minx);

 	}

 }