# HG changeset patch
# User Neil Muller <neil@dip.sun.ac.za>
# Date 1282908152 -7200
# Node ID f87a3485d927c9a58497425ee75edca0d6bb2ef5
# Parent  cc478e3a951e4490603cddf6267bff6520563c46
Add tool for making beeps

diff -r cc478e3a951e -r f87a3485d927 tools/gen_sound.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/gen_sound.py	Fri Aug 27 13:22:32 2010 +0200
@@ -0,0 +1,33 @@
+# Generate 'perfect' sine wave sounds
+
+# Design notes: produces ~= 0.5s raw CDDA audio - 44100 Hz, 16 bit signed values
+# Input is freq in Hz - 440 for A, etc. - must be an integer
+# Output is written the file beep<freq>.pcm
+# Convert to ogg with oggenc -r <file>
+
+import sys
+import math
+import struct
+
+
+CDDA_RATE = 44100
+MAX = 105*256 # Max value for sine wave
+
+def gen_sine(freq):
+    filename = 'beep%s.pcm' % freq
+    # We need to generate freq cycles and sample that CDDA_RATE times
+    samples_per_cycle = CDDA_RATE / freq
+    data = []
+    for x in range(samples_per_cycle):
+        rad = float(x) / samples_per_cycle * 2 * math.pi
+        y = MAX * math.sin(rad)
+        data.append(struct.pack('<i', y))
+    output = open(filename, 'w')
+    for x in range(freq/2):
+        output.write(''.join(data))
+    output.close()
+
+
+if __name__ == "__main__":
+    freq = int(sys.argv[1])
+    gen_sine(freq)