GDP

#!/usr/bin/env python

import gi

gi.require_version('Gst', '1.0')

gi.require_version('GstBase', '1.0')

from gi.repository import GObject, Gst, GstBase

import os

import gdp

import sys

import cPickle

import gdpsrc, gdpsink

if __name__ == '__main__':

    sys.stderr.write("THIS IS ONLY A PROOF-OF-CONCEPT, USE AT YOUR OWN RISK!\n")

    GObject.threads_init()

    Gst.init(None)

    # register the elements again, just in case

    Gst.Element.register(None, "gdpsrc", Gst.Rank.NONE, gdpsrc.GDPSrc)

    Gst.Element.register(None, "gdpsink", Gst.Rank.NONE, gdpsink.GDPSink)

    if len(sys.argv)<2:

        sys.stderr.write("Usage: %s <a valid pipeline>\n" % sys.argv[0])

        sys.stderr.write("Example: audiotestsrc ! gdpsink logname=xyz\n")

        sys.stderr.write("Example: gdpsrc logname=xyz ! autoaudiosink\n")

        sys.stderr.write("Valid properties are 'logname' and 'name'.\n")

        sys.exit(-1)

    pipeline_desc = " ".join(sys.argv[1:])

    # Not sure if escaping is allowed. If so, this doesn't work well.

    orig_elems = pipeline_desc.split("!")

    assert len(orig_elems)>=2

    # Because of a weird bug somewhere (most likely in Python Gstreamer),

    # setting properties for python plugins (other than 'name') does not

    # work from the pipeline description passed to Gst.parse_launch. It

    # does, however, work if we get a handle to the element and call

    # 'set_property' on it explicitly.

    # To get around this bug, we must parse the pipeline description, find

    # our particular elements, generate a pipeline without the property

    # assignments, create the pipeline by calling Gst.parse_launch, then

    # get all our elements, and individually set properties on them.

    # Original properties specified in the pipeline description

    # A list of dicts, each item in the list represents our elements

    gdp_elem_list = []

    # A list of strings representing elements in the modified pipeline desc

    new_elems = []

    for elem in orig_elems:

        # elem is simply a string representing an element and its property

        # assignment

        elem = elem.strip()

        _elem = elem.split(" ")[0]

        if _elem == "gdpsrc" or _elem == "gdpsink":

            # parse the properties.

            props = {}

            __prop_strs = elem.split(" ")[1:]

            for __prop_str in __prop_strs:

                __prop_str = __prop_str.strip()

                _tmp = __prop_str.split("=")

                props[_tmp[0]] = _tmp[1]

            # ensure that we have the 'name' set

            props["name"] = props.get("name",

                                "%s%d" % (_elem, len(gdp_elem_list)))

            # parsed properties, now recreate this element

            elem = "%s name=%s" % (_elem, props["name"])

            gdp_elem_list.append(props)

        new_elems.append(elem)

    new_pipeline_desc = " ! ".join(new_elems)

    sys.stderr.write("Modified original pipeline\n")

    sys.stderr.write("launching pipeline %s\n" % new_pipeline_desc)

    pipeline = Gst.parse_launch(new_pipeline_desc)

    # Now is the time to set properties to each of the GDP elements

    for props in gdp_elem_list:

        elem_name = props["name"]

        elem = pipeline.get_by_name(elem_name)

        for key in props:

            if key == "name":

                continue

            elem.set_property(key, props[key])

    # All set, ready to go now

    pipeline.set_state(Gst.State.PLAYING)

    loop = GObject.MainLoop()

    try:

        loop.run()

    except:

        pass

    pipeline.set_state(Gst.State.NULL)