[Development] i.MX6 zero copy video playback

[Thomas Senyk]

On Thursday, 27 February, 2014 17:57:43 Michael Olbrich wrote:
> Hi,
> 
> On Tue, Feb 18, 2014 at 10:18:36AM +0100, Thomas Senyk wrote:
> > On Thursday, 13 February, 2014 13:16:42 Michael Olbrich wrote:
> > > On Wed, Feb 12, 2014 at 10:43:25AM +0100, Thomas Senyk wrote:
> > > > I finally got around to polish and upstream zero copy video playback
> > > > for
> > > > the i.MX6.
> > > > 
> > > > The change:
> > > > https://codereview.qt-project.org/#change,76764
> > > > 
> > > > A video showcasing the functionality:
> > > > http://www.youtube.com/watch?v=pmxsWGhrrBQ
> > > 
> > > Nice. Are there any limitation regarding the input QVideoFrames? I've
> > > used
> > > glTexDirectVIVMap in the past, and I don't think that using it on
> > > malloc'ed
> > > memory ever worked for me.
> > 
> > never tried it on malloc'ed memory ... I think gstreamer somehow reserves
> > them in a specific memory block.
> > 
> > So the answer is: I don't know :)
> 
> So, I had some time to work with this. I found one limitation: the memory
> must be 64 Bytes aligned. Unfortunately I have no idea how this could be
> communicated upstream.
> I also found that the texture cache based on the virtual address is rather
> fragile. I've had several cases where different video frames had the same
> virtual address. I'm not sure how to fix this. Maybe some special meta data
> that can be used if provided or a special handle type?
> 
> Anyways, I've submitted some changes for review:
> 
> https://codereview.qt-project.org/#change,79447
> https://codereview.qt-project.org/#change,79448
> https://codereview.qt-project.org/#change,79449
> 
> Thomas, it would be great if you could test if this works for you.

Guess Andy was faster @ review :)

I very much like change 79447, I always though this should be solved better, 
but for some reason I never considered a config.test :)
just tested -> works for me!

@ 79448: where have you found video sources with all those formats?

@ 79449: yes, I fully agreed, but I don't have time to test right now.

Thanks
Thomas

> 
> Regards,
> Michael