1 files changed, 95 insertions, 0 deletions
diff --git a/channels/gentone.c b/channels/gentone.c
new file mode 100644
index 000000000..29bd88e91
--- /dev/null
+++ b/channels/gentone.c
@@ -0,0 +1,95 @@
+/* Generate a header file for a particular 
+   single or double frequency */
+
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#define CLIP 32635
+#define BIAS 0x84
+static float loudness=16384.0;
+
+static int calc_samples(int freq)
+{
+	int x, samples;
+	/* Calculate the number of samples at 8000hz sampling
+	   we need to have this wave form */
+	samples = 8000;
+	/* Take out common 2's up to six times */
+	for (x=0;x<6;x++) 
+		if (!(freq % 2)) {
+			freq /= 2;
+			samples /= 2;
+		}
+	/* Take out common 5's (up to three times */
+	for (x=0;x<3;x++) 
+		if (!(freq % 5)) {
+			freq /= 5;
+			samples /=5;
+		}
+	/* No more common factors. */
+	return samples;
+}
+
+int main(int argc, char *argv[])
+{
+	FILE *f;
+	int freq1, freq2;
+	float wlen1, wlen2;
+	float val;
+	int x, samples1, samples2=0, samples=0;
+	char fn[256];
+	if (argc < 3) {
+		fprintf(stderr, "Usage: gensound <name> <freq1> [freq2]\n");
+		exit(1);
+	}
+	freq1 = atoi(argv[2]);
+	if (argc > 3) 
+		freq2 = atoi(argv[3]);
+	else
+		freq2 = 0;
+	wlen1 = 8000.0/(float)freq1;
+	samples1 = calc_samples(freq1);
+	printf("Wavelength 1 (in samples): %10.5f\n", wlen1);
+	printf("Minimum samples (1): %d (%f.3 wavelengths)\n", samples1, samples1 / wlen1);
+	if (freq2) {
+		wlen2 = 8000.0/(float)freq2;
+		samples2 = calc_samples(freq2);
+		printf("Wavelength 1 (in samples): %10.5f\n", wlen2);
+		printf("Minimum samples (1): %d (%f.3 wavelengths)\n", samples2, samples2 / wlen2);
+	}
+	samples = samples1;
+	if (freq2) {
+		while(samples % samples2)
+			samples += samples1;
+	}
+	printf("Need %d samples\n", samples);
+	snprintf(fn, sizeof(fn), "%s.h", argv[1]);
+	if ((f = fopen(fn, "w"))) {
+		if (freq2) 
+			fprintf(f, "/* %s: Generated from frequencies %d and %d \n"
+			           "   by gentone.  %d samples  */\n", fn, freq1, freq2, samples); 
+		else
+			fprintf(f, "/* %s: Generated from frequency %d\n"
+			           "   by gentone.  %d samples  */\n", fn, freq1, samples); 
+		fprintf(f, "static short %s[%d] = {\n\t", argv[1], samples);
+		for (x=0;x<samples;x++) {
+			val = loudness * sin((freq1 * 2.0 * M_PI * x)/8000.0);
+			if (freq2)
+				val += loudness * sin((freq2 * 2.0 * M_PI * x)/8000.0);
+			fprintf(f, "%5d, ", (int)val);
+			if (!((x+1) % 8)) 
+				fprintf(f, "\n\t");
+		}
+		if (x % 15)
+			fprintf(f, "\n");
+		fprintf(f, "};\n");
+		fclose(f);
+		printf("Wrote %s\n", fn);
+	} else {
+		fprintf(stderr, "Unable to open %s for writing\n", fn);
+		return 1;
+	}
+	return 0;
+}