[gst-devel] editing list concept - still not sure

[Ronald Bultje]

On 2001.05.11 16:16:38 +0200 Christoph Scheurer wrote:
> On Fri, May 11, 2001 at 03:20:53PM +0200, Thomas Vander Stichele wrote:
> > I've just changed the format to XML because it's better suited for
> > this kind of thing, and I'm adding a sample XML input file here.  It
> > contains audio data, volume envelopes, and text data.
> I agree that XML is well suited for that purpose. I was thinking about
> that
> problem a little bit before, but I didn't implement anything yet.
> 
> I guess you would need basically three types of objects: timelines (or
> sequences), sources, and effects (or nodes), well, and clearly one sink.
> Each
> of them would produce a single YUV output stream. Timelines consist of a
> sequence of all three kinds of objects, sources only have an output
> stream, and
> effects can have as many input streams as they want. Typical sources
> would
> read (parts of) video streams from files, provide blank frames for
> delays, or
> produce a stream of identical frames from a single picture file. Some
> effects
> I could think of are resizing, de-interlacing, overlay, fade, ...
> 
> But if I understand it correctly, then this is, what the gstreamer
> framework
> provides and it is probably only neccessary to implement a lavtools
> source and
> turn the filters into gstreamer plugins. Or am I wrong about that?
 
That is true - but I didn't see anything about the editing list concept in
gstreamer yet. The framework is there, I know, and it is also there in the
mjpegtools. But you also want to use it ;-)

The whole idea here is that you have your NLE reading an editlist file and
then the NLE will create the sources, nodes etc, put them in the right
order. I thought it would be a good idea to have a generic format for these
editing lists, just to make things easy. So although the nodes, sources etc
exist in gstreamer, I want to make a generic concept of an editing list
file format to tell the NLE how to put these individual components together
to get the output video stream that we wanted.

Ronald

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