[gst-devel] Simple Video Sink Plugin

Simon Holm Thøgersen odie at cs.aau.dk
Tue Dec 5 21:09:19 CET 2006

tir, 05 12 2006 kl. 10:42 +0100, skrev Patrick Holthaus:
> Hello out there.
> My goal is to write a simple plugin that takes raw RGB Videos as an input
> and buffers it. There is no output needed because the content will be read
> by a Java Program.
> I have read the application development manual and plugin writers guide,
> and downloaded the sample plugin. With the help of that and some look
> into the source of the ximagesink plugin i tried to create a source file of
> my own. The result can be found here:
> http://wwwhomes.uni-bielefeld.de/pholthaus/public/gst/
> The source can be compiled without warnings etc. and .a / .la / .so files
> are copied to ~/.gstreamer-0.10/plugins . But even after removing
> ~/.gstreamer-0.10/registry.i686.xml and running gst-inspect-0.10 the plugin
> is NOT recognized.

When a gst-plugins compiles and install into the right location, but
doesn't show up running gst-inspect, it's a sign that it doesn't load
correctly. You should set GST_DEBUG=2 and see what error you get.

> My guess is, that the source code is faulty (as this is the first try where 
> almost shurely something is missing). I would appreciate any help. There
> have to be important things missing that i cannot figure out.

I tried downloading your code and found the following fatal issues

 - it wouldn't even compile since gst_plugin_debug_template was
undefined (solved by not setting debug category or introducing
 - not linking against libgstvideosink (add -lgstvideo-0.10 to LDFLAGS),
 - the code try to register the element as a GST_TYPE_VIDEO_SINK instead

I don't know why you haven't got the first issue (you can't have if you
says it compile). Number two might also be a non-issue in your setup if
you already link correctly, but the last is a fatal bug in the code.

You should try to run
 $ GST_DEBUG=2 gst-inspect-0.10 javasink
for yourself and see what it complains about, before you apply any fix
to get a feel for what's going on.

Hope that is helps,
Simon Holm Thøgersen

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