python/demos/demo_sink_multi.py: add multi channel version

diff --git a/python/demos/demo_sink_multi.py b/python/demos/demo_sink_multi.py
new file mode 100755 (executable)
index 0000000..dcf20da
--- /dev/null
+++ b/python/demos/demo_sink_multi.py
@@ -0,0 +1,31 @@
+#! /usr/bin/env python
+
+import sys
+from aubio import source, sink
+
+if __name__ == '__main__':
+    if len(sys.argv) < 3:
+        print 'usage: %s <inputfile> <outputfile> [samplerate] [hop_size]' % sys.argv[0]
+        sys.exit(1)
+
+    if len(sys.argv) > 3: samplerate = int(sys.argv[3])
+    else: samplerate = 0
+    if len(sys.argv) > 4: hop_size = int(sys.argv[4])
+    else: hop_size = 256
+
+    f = source(sys.argv[1], samplerate, hop_size)
+    if samplerate == 0: samplerate = f.samplerate
+    g = sink(sys.argv[2], samplerate, f.channels)
+
+    total_frames, read = 0, hop_size
+    while read:
+        vec, read = f.do_multi()
+        g.do_multi(vec, read)
+        total_frames += read
+    print "wrote", "%.2fs" % (total_frames / float(samplerate) ),
+    print "(", total_frames, "frames", "in",
+    print total_frames / f.hop_size, "blocks",
+    print "of", f.channels, "channels",
+    print "at", "%dHz" % f.samplerate, ")",
+    print "from", f.uri,
+    print "to", g.uri