aubioinput.py: added first draft of generic gst input

diff --git a/interfaces/python/aubioinput.py b/interfaces/python/aubioinput.py
new file mode 100644 (file)
index 0000000..c8f235e
--- /dev/null
+++ b/interfaces/python/aubioinput.py
@@ -0,0 +1,119 @@
+#! /usr/bin/python
+
+import pygst
+pygst.require('0.10')
+import gst
+import gobject
+gobject.threads_init ()
+
+def gst_buffer_to_numpy_array(buffer, chan):
+    import numpy
+    samples = numpy.frombuffer(buffer.data, dtype=numpy.float32) 
+    samples.resize([len(samples)/chan, chan])
+    return samples.T
+
+class AubioSink(gst.BaseSink):
+    _caps = gst.caps_from_string('audio/x-raw-float, \
+                    rate=[ 1, 2147483647 ], \
+                    channels=[ 1, 2147483647 ], \
+                    endianness={ 1234, 4321 }, \
+                    width=32')
+
+    __gsttemplates__ = ( 
+            gst.PadTemplate ("sink",
+                gst.PAD_SINK,
+                gst.PAD_ALWAYS,
+                _caps),
+            )
+
+    def __init__(self, name, process):
+        self.__gobject_init__()
+        self.set_name(name)
+        self.process = process
+        self.adapter = gst.Adapter()
+        self.set_property('sync', False)
+        self.pos = 0
+
+    def set_property(self, name, value): 
+        if name == 'hopsize':
+            # blocksize is in byte, convert from hopsize 
+            from struct import calcsize
+            self.set_property('blocksize', value * calcsize('f'))
+        else:
+            super(gst.BaseSink, self).set_property(name, value)
+
+    def do_render(self, buffer):
+        blocksize = self.get_property('blocksize')
+        caps = buffer.get_caps()
+        chan = caps[0]['channels']
+        self.adapter.push(buffer)
+        while self.adapter.available() >= blocksize:
+            block = self.adapter.take_buffer(blocksize)
+            v = gst_buffer_to_numpy_array(block, chan)
+            if self.process:
+                self.process(v, self.pos)
+            self.pos += 1    
+        return gst.FLOW_OK
+
+gobject.type_register(AubioSink)
+
+class aubioinput:
+    def __init__(self, location, process = None, hopsize = 512,
+            caps = None):
+        from os.path import isfile
+        if not isfile(location):
+            raise ValueError, "location should be a file"
+        src = gst.element_factory_make('filesrc')
+        src.set_property('location', location)
+        dec = gst.element_factory_make('decodebin')
+        dec.connect('new-decoded-pad', self.on_new_decoded_pad)
+        conv = gst.element_factory_make('audioconvert')
+        rsmpl = gst.element_factory_make('audioresample')
+        capsfilter = gst.element_factory_make('capsfilter')
+        if caps:
+            capsfilter.set_property('caps', gst.caps_from_string(caps))
+        sink = AubioSink("AubioSink", process = process)
+        sink.set_property('hopsize', hopsize) # * calcsize('f'))
+
+        self.pipeline = gst.Pipeline()
+
+        self.bus = self.pipeline.get_bus()
+        self.bus.add_signal_watch()
+        self.bus.connect('message::eos', self.on_eos)
+
+        self.apad = conv.get_pad('sink')
+
+        self.pipeline.add(src, dec, conv, rsmpl, capsfilter, sink)
+
+        src.link(dec)
+        gst.element_link_many(conv, rsmpl, capsfilter, sink)
+
+        self.mainloop = gobject.MainLoop()
+        self.pipeline.set_state(gst.STATE_PLAYING)
+        self.mainloop.run()
+
+    def on_new_decoded_pad(self, element, pad, last):
+        caps = pad.get_caps()
+        name = caps[0].get_name()
+        #print 'on_new_decoded_pad:', name
+        if name == 'audio/x-raw-float' or name == 'audio/x-raw-int':
+            if not self.apad.is_linked(): # Only link once
+                pad.link(self.apad)
+
+    def on_eos(self, bus, msg):
+        self.bus.remove_signal_watch()
+        self.pipeline.set_state(gst.STATE_PAUSED)
+        self.mainloop.quit()
+
+if __name__ == '__main__':
+    import sys
+    if len(sys.argv) < 2:
+        print "Usage: %s <filename>" % sys.argv[0]
+        sys.exit(1)
+    for filename in sys.argv[1:]:
+        peak = [0., 0.]
+        def process(buf, hop):
+            peak[0] = max( peak[0], abs(buf.max()) )
+            peak[1] = min( peak[1], abs(buf.min()) )
+        aubioinput(filename, process = process, hopsize = 512)
+        print "Finished reading %s, peak value is %f" % (filename, min(peak))