creating custom sink in python fails

[Jan Spurný]

Hi,

I have problem with (probably) python binding for gstreamer-1.0 (1.4.4.0) - I was porting some code from gstreamer-0.10 (pygst) to new gstreamer-1.0 and I'm not able to get elements written in python to work. This is minimal working example (python2.7):

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import gi
gi.require_version('Gst', '1.0')
from gi.repository import Gst
from gi.repository import GstBase
from gi.repository import GObject

GObject.threads_init()
Gst.init()

class MySink(GstBase.BaseSink):
    __gstmetadata__ = ('My Sink', 'Sink', 'Sink', 'foo bar')
    __gsttemplates__  = (
        Gst.PadTemplate.new("sink",
            Gst.PadDirection.SINK, Gst.PadPresence.ALWAYS,
            Gst.caps_from_string('text/plain')),)

def plugin_init(plugin, userarg):
    t = GObject.type_register(MySink)
    Gst.Element.register(plugin, 'my_sink', 0, t)
    return True

version = Gst.version()
r = Gst.Plugin.register_static_full(
    version[0], version[1], 'my_plugin', 'my plugin desc',
    plugin_init, '1.0', 'Proprietary', 'abc', 'def', 'ghi', None)

s = MySink()
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and it throws a CRITICAL error:

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$ ./mysink.py
(python2:18618): GStreamer-WARNING **: Element factory metadata for 'my_sink' has no valid long-name field
** (python2:18618): CRITICAL **: gst_base_sink_init: assertion 'pad_template != NULL' failedI'm not that worried about the warning, but that CRITICAL error means the element has no sinkpad and can't be linked.
---------------------------------------------------------------------

And worst thing - if I remove __gsttemplates__ and __gstmetadata__ completely, NOTHING changes. It seems to me that BaseSink.__init__() doesn't see it.

Does anyone have any idea what I'm doing wrong? Also I would greatly appreciate any documentation, examples or tutorials on python binding for gstreamer-1.0, because I wasn't able to find much

Thanks,
Jan Spurny