Re: ClutterGst plans

[Stefan de Konink <stefan konink de>]

On 02/04/2013 07:00 PM, Lionel Landwerlin wrote:
> On 04/02/13 17:21, Stefan de Konink wrote:
> > On 02/04/2013 06:11 PM, Lionel Landwerlin wrote:
> > > Ok, so that's going to be supported as well, though you can already do
> > > it at the moment with a ClutterClone.
> > To be completely honest, my biggest interest are:
> >   - gapless playout of video
> >     (hence an event to properly cue the next video)
>
> Define gapless. If you're talking about gap detection, I might be wrong
> but it seems outside of ClutterGst's scope (at least I don't know anyone
> interested/looking at this).

I want to play two video's straight after eachother without a black
frame in between. This requires that the second video is properly
scheduled in time by the framework, and not just openend when the first
video has reached its last frame.

> >   - proper hardware acceleration that doesn't require to
> >     "git pull hair" when compiling/configuring/runnig.
>
> Sadly that's going to depend a lot on your drivers. As far as I know
> Gstreamer 1.0 (on which ClutterGst master depends) does not support
> hardware acceleration at the moment.
> But yeah definitely interested in simpler hw accelerated playback.

Gstreamer does support hardware acceleration and some work on ClutterGst
was done to make use of vaapi. On gentoo I got it to work with an nVidia
card. Reproducing it on Ubuntu was impossible without crashes. Probably
tells you more about my development system than the users I want to show
my work to ;)

> >   - less crashes with Gst
>
> Do you have bug reports about this? If that's Gstreamer crashes, we
> won't be able to do much about it...

I guess I'll make something that it can be reproduced, it is not always
obvious were the bug occurs. For example: who to blame when the pane
were the video should be embedded is not filled, but a separate X11
display is started?

> >   - sync between different files
>
> You mean syncing 2 playbacks or 2 different files?

Actually both. For example taking a separate voicetrack for a videofile
and want to have it sync up with the audio.

> >   - some decent examples introspection examples
>
> That's my plan.
>
> I think overall the plan here is to allow more flexibility in
> manipulating video streams in a Clutter scene.
> So obviously more animations/effects using whole or part of a video.
> We don't really care that much about what's going on at the Gstreamer
> level.

I guess animations are 'nice' once they are accelerated, but for most
scenario's having properly triggered events and a transparent loading
mechanism of video, audio and playlists maybe a lower target that makes
more people happy and more apps to start to use the work done.

I do appreciate that this discussion is going on :-)


Stefan