added repeater example

examples/repeater.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+
+"""
+Simple repeater that monitors a single directory using inotify, and if
+an image appears, it tries to repeat it on using the PyAudio example,
+trying to match the mode used for receiving it. It can be tested by
+simply copying/linking images to the directory or suing an SSTV
+receiver such as slowrx or QSSTV.
+"""
+
+from __future__ import print_function
+from pyinotify import WatchManager, Notifier, ProcessEvent, IN_CREATE
+from pyaudio_sstv import PyAudioSSTV
+from color import MartinM1, MartinM2, ScottieS1, ScottieS2
+from grayscale import Robot8BW, Robot24BW
+from PIL import Image
+from os import path
+
+# matches the abbreviations used by slowrx and QSSTV
+MODE_MAP = {
+        'M1': MartinM1,
+        'M2': MartinM2,
+        'S1': ScottieS1,
+        'S2': ScottieS2,
+        'R8BW': Robot8BW,
+        'R24BW': Robot24BW,
+        }
+
+class EventHandler(ProcessEvent):
+    def process_IN_CREATE(self, event):
+        filename = event.pathname
+        print('Found image', filename)
+        mode = get_module_for_filename(filename)
+        img = Image.open(filename)
+        if mode is None:
+            mode = get_module_for_image(img)
+        if mode is None:
+            print('No suitable mode found to repeat', filename)
+            return
+        print('Repeating image using', mode.__name__)
+        sstv = mode(img, 44100, 16)
+        sstv.vox_enabled = True
+        PyAudioSSTV(sstv).execute()
+
+def get_module_for_filename(filename):
+    basename, _ = path.splitext(path.basename(filename))
+    for mode, module in MODE_MAP.iteritems():
+        if mode in basename:
+            return module
+
+def get_module_for_image(image):
+    size = image.size
+    for mode in MODE_MAP.itervalues():
+        if all(i >= m for i, m in zip(size, (mode.WIDTH, mode.HEIGHT))):
+            return mode
+
+def main():
+    from sys import argv, stderr
+    try:
+        directory = argv[1]
+    except IndexError:
+        print("Usage: {0} <directory>".format(argv[0]), file=stderr)
+    else:
+        watch(directory)
+
+def watch(directory):
+    wm = WatchManager()
+    notifier = Notifier(wm, EventHandler())
+    wm.add_watch(directory, IN_CREATE)
+    notifier.loop()
+
+if __name__ == '__main__':
+    main()