# In this program the first filesource plays the first two seconds of my audio
# file (passed in the first argument) and the second plays the next two seconds.
# The start time of the second filesource is 2, which means that it should start
# right after the first filesource but it does not, it waits for 2 more seconds
# and starts 4 seconds in. When I make the media-start property of the second
# filesource 0, it does start right after the first filesource with not pause.
# Of course it then plays the first two seconds of the file over again, rather
# than the next two.

#!/usr/bin/python
import pygst
pygst.require("0.10")
import gst
import gobject
import sys

def OnPad(comp, pad):
        convpad = compconvert.get_compatible_pad(pad, pad.get_caps())
        pad.link(convpad)

pipeline = gst.Pipeline()
comp = gst.element_factory_make("gnlcomposition")
pipeline.add(comp)
comp.connect("pad-added", OnPad)

compconvert = gst.element_factory_make("audioconvert")
pipeline.add(compconvert)

sink = gst.element_factory_make("alsasink")
pipeline.add(sink)
compconvert.link(sink)

audio1 = gst.element_factory_make("gnlfilesource")
comp.add(audio1)
audio1.set_property("location", sys.argv[1])
audio1.set_property("start", 0 * gst.SECOND)
audio1.set_property("duration", 2 * gst.SECOND)
audio1.set_property("media-start", 0 * gst.SECOND)
audio1.set_property("media-duration", 2 * gst.SECOND)

audio2 = gst.element_factory_make("gnlfilesource")
comp.add(audio2)
audio2.set_property("location", sys.argv[1])
audio2.set_property("start", 2 * gst.SECOND)
audio2.set_property("duration", 2 * gst.SECOND)
audio2.set_property("media-start", 2 * gst.SECOND)
audio2.set_property("media-duration", 2 * gst.SECOND)

pipeline.set_state(gst.STATE_PLAYING)
gobject.MainLoop().run()