PythonGStreamer - Revision history

Michael Murtaugh at 10:41, 1 June 2009

2009-06-01T10:41:26Z

← Older revision		Revision as of 12:41, 1 June 2009
Line 27:		Line 27:
	</source>		</source>

	== ~~A command-line level analyzer~~ ==		== Other Examples ==

	[[Level.py]]		* [[Level.py \| Level analyzer]]
			* [[Spectrum.py \| Spectral analysis]]
	~~== A command-line spectrum analyzer ==~~

	[[Spectrum.py]]

	~~== Other Examples ==~~
	* [[ListeningAndWatching]]		* [[ListeningAndWatching]]

Michael Murtaugh: /* A command-line spectrum analyzer */

2009-06-01T10:40:30Z

A command-line spectrum analyzer

@@ Line 33: / Line 33: @@
 == A command-line spectrum analyzer ==
-[[Media:Spectrum.zip]]
+[[Spectrum.py]]
 == Other Examples ==
 * [[ListeningAndWatching]]

Michael Murtaugh: /* A command-line level analyzer */

2009-06-01T10:36:10Z

A command-line level analyzer

@@ Line 29: / Line 29: @@
 == A command-line level analyzer ==
-[[Media:Level.zip]]
+[[Level.py]]
 == A command-line spectrum analyzer ==

Michael Murtaugh at 09:53, 1 June 2009

2009-06-01T09:53:49Z

@@ Line 25: / Line 25: @@
 	audiotestsrc.set_property("freq", f)
 	time.sleep(1.0/random.randint(1, 10))
 </source>

Michael Murtaugh: /* Generating random tones = */

2009-06-01T09:52:12Z

Generating random tones =

← Older revision		Revision as of 11:52, 1 June 2009
Line 1:		Line 1:
	Using [[Python]] to program [[GStreamer]]		Using [[Python]] to program [[GStreamer]]

	== Generating random tones ===		== Generating random tones ==

	A python random oscillator stream:		A python random oscillator stream:

Michael Murtaugh: /* Python GStreamer */

2009-06-01T09:52:02Z

Python GStreamer

New page

Using [[Python]] to program [[GStreamer]]

== Generating random tones ===

A python random oscillator stream:
<source lang="python">
import pygst
pygst.require("0.10")
import gst

pipeline = gst.Pipeline("mypipeline")
audiotestsrc = gst.element_factory_make("audiotestsrc", "audio")
pipeline.add(audiotestsrc)
sink = gst.element_factory_make("alsasink", "sink")
pipeline.add(sink)
audiotestsrc.link(sink)
audiotestsrc.set_property("freq", 800)
pipeline.set_state(gst.STATE_PLAYING)

import time, random

while 1:
f = random.randint(200, 800)
print "setting freq to: %d" % f
audiotestsrc.set_property("freq", f)
time.sleep(1.0/random.randint(1, 10))
</source>

== A command-line spectrum analyzer ==

[[Media:Spectrum.zip]]

<source lang="python">
import pygst
pygst.require("0.10")
import gst, gobject
import time, thread

class Spectrum:

def __init__(self):
# Create a gstreamer pipeline, listen to it's messages via on_message callback
# listener_desc = 'alsasrc ! spectrum ! fakesink'
listener_desc = 'alsasrc ! spectrum bands=64 ! fakesink'
self.listener = gst.parse_launch(listener_desc)
bus = self.listener.get_bus()
bus.add_signal_watch()
bus.connect("message", self.on_message)

def on_message (self, bus, message):
""" callback function for gstreamer messages """
s = message.structure
# print "message.name", s.get_name()
# print "message.structure.keys", s.keys()
if s and s.get_name() == "spectrum":
# spectrum messages have 'endtime', 'timestamp', 'stream-time', 'running-time', 'duration', 'magnitude'
# print len(s['magnitude'])
print "data: " + " ".join([str(x) for x in s['magnitude']])
return True

def start(self):
self.listener.set_state(gst.STATE_PLAYING)
while True:
time.sleep(1)

# Run the Spectrum object in it's own thread, then start the gobject.MainLoop as required
spectrum = Spectrum()
thread.start_new_thread(spectrum.start, ())
gobject.threads_init()
loop = gobject.MainLoop()
loop.run()
</source>

== Other Examples ==
* [[ListeningAndWatching]]