[gst-devel] (no subject)

[Benjamin Otte]

Quoting "Amadeus W. Mozart" <amadeus84 at sbcglobal.net>:

> I have some medical clips and I have to do some image segmentation
> and other processing on each individual frame. Usually the clips
> are in quicktime format, and the frames within are jpeg.
> So I need to read the clip from the disk, access each of its frames,
> do my processing and then display the frames. My processing may not
> be real time, but that's not a major concern for now. I can just
> dump the output to a file, and display it afterwards.
> 
> I'm new to gstreamer, and after reading what it can do and trying
> out some of the examples, I liked the idea, but I don't know very 
> well how to go about it. In particular, how do I "steal" (or access)
> the individual frames from the clip? 
> 
It sounds like what you want to do is write an element. There already exist 
plugins that do stuff to/with the pipeline, like the effecTV plugins. You might 
want to try gst-launch videotestsrc ! warpTV ! ximagesink and compare that with 
gst-launch videotestsrc ! ximagesink to see how easily you can modify images by 
inserting elements.
There is a lot of simple elements inside gst-plugins that use the 
GstVideoFilter code to modify images. (the timeoverlay plugin comes to mind, 
too.)
Decoding and later storing those images should be pretty easy, too and just 
depend on getting the corect pipeline going.

> The only video pipeline that I was able to get working so far was
> 
> gst-launch videotestsrc ! sdlvideosink
> 
You should definitely play around a bit with gst-launch to get a feel for what 
is possible and how the whole framework works. Being fluid in gst-launch syntax 
also helps when talking to us developers and trying to make as reproduce 
interesting things (most often bugs people stumble onto).


Benjamin