added proper command line interface

run.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+from __future__ import print_function
+from PIL import Image
+from argparse import ArgumentParser
+from sys import stderr
+import color, grayscale
+
+SSTV_MODULES = [color, grayscale]
+
+def main():
+	module_map = build_module_map()
+	parser = ArgumentParser(
+			description='Converts an image to an SSTV modulated WAV file.')
+	parser.add_argument('img_file', metavar='image.png',
+			help='input image file name')
+	parser.add_argument('wav_file', metavar='output.wav',
+			help='output WAV file name')
+	parser.add_argument('--mode', dest='mode', default='MartinM1', choices=module_map,
+			help='image mode (default: Martin M1)')
+	parser.add_argument('--rate', dest='rate', type=int, default=48000,
+			help='sampling rate (default: 48000)')
+	parser.add_argument('--bits', dest='bits', type=int, default=16,
+			help='bits per sample (default: 16)')
+	args = parser.parse_args()
+	image = Image.open(args.img_file)
+	mode = module_map[args.mode]
+	if not all(i >= m for i, m in zip(image.size, (mode.WIDTH, mode.HEIGHT))):
+		print(('Image must be at least {m.WIDTH} x {m.HEIGHT} pixels '
+				'for mode {m.__name__}').format(m=mode), file=stderr)
+		raise SystemExit(1)
+	s = mode(image, args.rate, args.bits)
+	s.write_wav(args.wav_file)
+
+def build_module_map():
+	module_map = {}
+	for module in SSTV_MODULES:
+		for mode in module.MODES:
+			module_map[mode.__name__] = mode
+	return module_map
+
+
+if __name__ == '__main__':
+	main()

sstv.py

@@ -93,11 +93,3 @@ class SSTV(object):
 
 def byte_to_freq(value):
 	return FREQ_BLACK + FREQ_RANGE * value / 255
-
-
-if __name__ == '__main__':
-	from PIL import Image
-	from grayscale import Robot8BW
-	image = Image.open('160x120bw.png')
-	s = Robot8BW(image, 48000, 16)
-	s.write_wav('test.wav')