shithub: neindaw

ref: 72f3156830b1458e856c0a5171a4042e62d3b8ac
dir: /sample/sample.c/

#include <u.h>
#include <libc.h>

static void
usage(void)
{
	print("usage: %s [-b buf_frames] [-c channels]\n", argv0);
	exits("usage");
}

void
main(int argc, char **argv)
{
	int bufsz, bufframes, framesz, chan, n, r, end, i;
	float f;
	u8int *b;

	bufframes = 2048;
	chan = 1;

	ARGBEGIN{
	case 'b':
		bufframes = atoi(EARGF(usage()));
		break;
	case 'c':
		chan = atoi(EARGF(usage()));
		break;
	default:
		usage();
	}ARGEND

	if (bufframes < 1)
		sysfatal("invalid buffer size: %d frames", bufframes);
	if (chan < 1)
		sysfatal("invalid number of channels: %d", chan);

	framesz = chan * 4;
	bufsz = bufframes * framesz;
	b = malloc(bufsz);

	n = 0;
	for (;;) {
		r = read(0, b+n, bufsz-n);
		if (r < 0)
			exits("read failed");
		else if (r == 0)
			break;
		n += r;

		end = n & ~(framesz-1);
		if (end < 1)
			continue;

		for (; end > 0; end -= framesz) {
			for (i = 0; i < chan; i++) {
				f = *(float*)(b + end - framesz - i*4);
				if (f != 0)
					goto out;
			}
		}
out:
		if (end == 0)
			break;

		if (write(1, b, end) != end)
			exits("write failed");
		n -= end;
		memmove(b, b+end, n);
	}

	exits(nil);
}