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

[Ronald Bultje]

On 2001.05.11 17:04:16 +0200 Christoph Scheurer wrote:
> On Fri, May 11, 2001 at 04:33:18PM +0200, Ronald Bultje wrote:
> > 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.
> I see. I think writing the editlist in XML is a good idea. For the NLE
> you
> would then have a single timeline as the document root and then a
> hierarchical
> structure that you can follow recursively, like:
> 
> |      *
> |      | video
> |      | file 1
> |      |
> |      *
> |      *-overlay filter
> |          *          *
> |          | video    |
> |          | file 2   | blank
> |          |          *
> |          |          *-overlay filter
> |          |              *          *
> |          |              | file 3   | picture
> |          |              |          |
> |          |              |          |
> |          |          *---*----------*
> |          |          *
> |          |          | blank
> |          |          |
> |      *---*----------*
> |      *
> |      | video
> |      | file 3
> |      |
> V      *
> time
> 
> You would have to make the filters behave correctly if one (or more)
> input
> stream is blank (e.g. don't do the overlay). If the NLE needs a specific
> frame
> it looks on the main time-line which element is currently active, and
> then
> looks on its inputs and so on recursively until it gets to the correct
> frame
> number relative to the main time-line.
> 
> Does that seem reasonable?

XML sounds reasonable although I never saw an XML page...
I especially like the idea of having the 'root' timeline - makes searching
quite easy (provided you make it work regarding to that root timeline).

I'll look at this later tonight (and send more e-mails) :-)

Ronald 

-- 
---------------------------------------------------.
--   .-.    | Ronald Bultje                        |
--   /V\    | Running: Linux 2.4.4 and OpenBSD 2.8 |
--  // \\   | E-mail : rbultje at ronald.bitfreak.net |
-- /(   )\  | WWW    : http://ronald.bitfreak.net/ |
--  ^^-^^   |    *** Warning: Unix Addicted ***    |
---------------------------------------------------'