[gst-devel] Newbie question - how to get video frames from pipeline

[Tim-Philipp Müller]

On Sun, 2009-03-29 at 23:02 +0200, Štěpán wrote:

>     I am trying to code get video frames from gstreamer pipeline, so I
> can do additional processing with them and draw each frame on screen via
> Irrlicht engine. I was able to do it using ffmpeg, but I am not able to
> get this done in gstreamer. The problem I am facing (and I am sure that
> this problem is very trivial) is that I cannot find a way how to get
> each (video)frame from gstreamer pipeline.
> Nevertheless, I found two ways, how this could be done. The first is use
> of appsink, and the second is to write my own (video)sink.

These are both good methods. There is also gdkpixbufsink which
essentially gives you RGB data (in a GdkPixbuf structure), and then
there is also the possibility to just use fakesink and the "handoff"
signal (but that's been replaced by appsink really).

> Unfortunately, I was not able to do it in neither way, mainly due to the
> lack of example code, or my poor experience with gstreamer. So, my
> question is, which way should I go (use appsink, or extend (video)sink)
> and where to start with learning of how to accomplish this.

Here's a simple example demonstrating how to extract raw RGB video
frames with appsink:

http://cgit.freedesktop.org/gstreamer/gst-plugins-base/tree/tests/examples/snapshot/snapshot.c

Hope this helps.

Cheers
 -Tim