[gstreamer-bugs] [Bug 523393] New: Linking a tee element to multiple audio convert elements causes exponential caps growth on the tee

[GStreamer (bugzilla.gnome.org)]

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  GStreamer | gstreamer (core) | Ver: 0.10.17
           Summary: Linking a tee element to multiple audio convert elements
                    causes exponential caps growth on the tee
           Product: GStreamer
           Version: 0.10.17
          Platform: Other
        OS/Version: All
            Status: UNCONFIRMED
          Severity: critical
          Priority: Normal
         Component: gstreamer (core)
        AssignedTo: gstreamer-bugs at lists.sourceforge.net
        ReportedBy: jcekstrom at gmail.com
         QAContact: gstreamer-bugs at lists.sourceforge.net
     GNOME version: Unspecified
   GNOME milestone: Unspecified


Please describe the problem:
Linking a tee element to multiple audio convert elements causes exponential
Caps growth on the tee which causes slow/hung pipeline construction.  If 1-3
audio convert elements are linked to the tee, caps appear relatively normal. 
The more elements that are linked to the tee, the larger the caps grows.  If 13
audioconvert elements are linked in the pipeline fails (killed after a couple
hours) to construct.

Steps to reproduce:
Run "python tee_test.py <video file> <number of elements to connect to the
tee>"  for example "python tee_test.py foo.avi 13"

http://www.ekstrom.org/~jce/tee_test.py


Actual results:
The pipeline hangs in creation and the caps of the tee element appear to grow
exponentially. A smaller number of elements connected to the tee slows pipeline
creation down, but exhibits the problem of tee caps growth.

Expected results:
The caps to be an aggregate at a minimum, not exponential growth of the caps on
the tee element.

Does this happen every time?
yes

Other information:
# tee_test.py - python code to reproduce the bug
import gobject
gobject.threads_init()
import pygst
pygst.require('0.10')
import gst, sys, os

def Main(filename, forks):
    test = Test(filename, int(forks))
    return 0

class Test(object):
    def __init__(self, filename, forks):
        self.pipeline = gst.Pipeline()

        source = gst.element_factory_make('filesrc')
        source.set_property('location', filename)
        decode = gst.element_factory_make('decodebin')
        self.vidsink = gst.element_factory_make('fakesink')
        self.tee = gst.element_factory_make('tee')
        self.pipeline.add(source, decode, self.vidsink, self.tee)
        source.link(decode)
        for i in range(forks):
            audioconvert = gst.element_factory_make('audioconvert')
            encoder = gst.element_factory_make('vorbisenc')
            sink = gst.element_factory_make('fakesink')
            self.pipeline.add(audioconvert, encoder, sink)
            self.tee.link(audioconvert)
            audioconvert.link(encoder)
            encoder.link(sink)

        decode.connect('new-decoded-pad', self.NewDecodedPad)
        decode.connect('no-more-pads', self.DecodeBinDone)

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

    def NewDecodedPad(self, element, pad, arg):
        print 'DECODE NEW PAD', element, arg, pad
        caps = pad.get_caps()
        if caps[0].get_name().startswith('audio/'):
            print 'linking to tee'
            element.link(self.tee)
        else:
            element.link(self.vidsink)

    def DecodeBinDone(self, element):
        DisplayBin(self.pipeline)

def DisplayCaps(caps, level):
    for cap in caps:
        print "%s%s"%(level,cap.to_string()[:180])

def DisplayPad(pad, level):
    peerpad = pad.get_peer()
    peerparentname = ""
    peername = ""
    if peerpad:
        peername = peerpad.get_name()
        peerparentname = peerpad.get_parent().get_name()
    else:
        print "++++++++++++  ERROR NO PAD ++++++++++++++"
    print "%s%s: %s %d, A:%d, B:%d, L:%d<==> %s:%s" % (level, type(pad),
pad.get_name(), len(pad.get_caps()), pad.is_active(), pad.is_blocked(),
pad.is_linked(), peerparentname, peername)
    if pad.is_blocked():
        print "****** BLOCKED ******"
    DisplayCaps(pad.get_caps(), "    %s"%(level))

def DisplayElement(element, level):
    print "%s%s: %s" % (level, type(element), element.get_name())
    for pad in element.pads():
        DisplayPad(pad, "%s    "%level)


def DisplayBin(bin, level="", parents=True):
    if parents:
        while bin.get_parent():
            bin = bin.get_parent()

    print "%s%s: %s" % (level, type(bin), bin.get_name())

    for pad in bin.pads():
        DisplayPad(pad, "%s    "%level)

    for element in bin.elements():
        if isinstance(element, gst.Bin):
            DisplayBin(element, "%s    "%level, False)
        elif isinstance(element, gst.Element):
            DisplayElement(element, "%s    "%level)
        else:
            print "ERROR"

if __name__ == '__main__':
    try:
        sys.exit(Main(*sys.argv[1:]))
    except TypeError:
        print 'Usage: gsttest.py <file> <forks>'


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