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| </source> | | </source> |
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| == A command-line level analyzer == | | == Other Examples == |
| | |
| [[Media:Level.zip]]
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| | |
| <source lang="python">
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| import pygst
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| pygst.require("0.10")
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| import gst, gobject
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| import time, thread
| |
| | |
| class Level:
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| | |
| def __init__(self):
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| self.min = None
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| self.max = None
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| self.slider = 0.0
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| | |
| # Create a gstreamer pipeline, listen to it's messages via on_message callback
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| listener_desc = 'alsasrc ! level ! fakesink'
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| self.listener = gst.parse_launch(listener_desc)
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| bus = self.listener.get_bus()
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| bus.add_signal_watch()
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| bus.connect("message", self.on_message)
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| | |
| def on_message (self, bus, message):
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| """ callback function for gstreamer messages """
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| # print "message.name", s.get_name()
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| s = message.structure
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| # print "message.structure.keys", s.keys()
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| if s and s.get_name() == "level":
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| # The Level module seems to provide the following data: 'endtime', 'timestamp', 'stream-time', 'running-time', 'duration', 'rms', 'peak', 'decay'
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| # In this case we will just look at the "rms" value (representing relative loudness of the signal)
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| # It's a stereo (two-channel) value, so we just take the first one (left?)
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| loudness = s['rms'][0]
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| | |
| # update min and max
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| if (self.min==None or loudness<self.min):
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| self.min = loudness
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| if (self.max==None or loudness>self.max):
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| self.max = loudness
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|
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| # calculate "slider" (a 0 - 1 value, from min to max)
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| if (self.min != self.max):
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| self.slider = float(loudness - self.min) / (self.max - self.min)
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| # if self.slider < 0.25: self.slider = 0
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| print self.slider
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| return True
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| def start(self):
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| self.listener.set_state(gst.STATE_PLAYING)
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| while True:
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| time.sleep(1)
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| | |
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| # Run the Level object in it's own thread, then start the gobject.MainLoop as required
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| level = Level()
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| thread.start_new_thread(level.start, ())
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| gobject.threads_init()
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| loop = gobject.MainLoop()
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| loop.run()
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| </source>
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| | |
| == A command-line spectrum analyzer ==
| |
| | |
| [[Media:Spectrum.zip]]
| |
| | |
| <source lang="python">
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| import pygst
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| pygst.require("0.10")
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| import gst, gobject
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| import time, thread
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|
| |
|
| class Spectrum:
| | * [[Level.py | Level analyzer]] |
| | | * [[Spectrum.py | Spectral analysis]] |
| def __init__(self):
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| # Create a gstreamer pipeline, listen to it's messages via on_message callback
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| # listener_desc = 'alsasrc ! spectrum ! fakesink'
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| listener_desc = 'alsasrc ! spectrum bands=64 ! fakesink'
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| self.listener = gst.parse_launch(listener_desc)
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| bus = self.listener.get_bus()
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| bus.add_signal_watch()
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| bus.connect("message", self.on_message)
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| | |
| def on_message (self, bus, message):
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| """ callback function for gstreamer messages """
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| s = message.structure
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| # print "message.name", s.get_name()
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| # print "message.structure.keys", s.keys()
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| if s and s.get_name() == "spectrum":
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| # spectrum messages have 'endtime', 'timestamp', 'stream-time', 'running-time', 'duration', 'magnitude'
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| # print len(s['magnitude'])
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| print "data: " + " ".join([str(x) for x in s['magnitude']])
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| return True
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| | |
| def start(self):
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| self.listener.set_state(gst.STATE_PLAYING)
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| while True:
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| time.sleep(1)
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| # Run the Spectrum object in it's own thread, then start the gobject.MainLoop as required
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| spectrum = Spectrum()
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| thread.start_new_thread(spectrum.start, ())
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| gobject.threads_init()
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| loop = gobject.MainLoop()
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| loop.run()
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| </source>
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| | |
| == Other Examples ==
| |
| * [[ListeningAndWatching]] | | * [[ListeningAndWatching]] |
