[maemo-developers] [maemo-developers] libXv and xvimagesink

From: Charles 'Buck' Krasic krasic at cs.ubc.ca
Date: Mon Aug 28 22:00:46 EEST 2006
Hash: SHA1


There has been some discussion of this issue on this mailing list.  
You may want to search the archives.

To summarize the situation briefly:

There is no Xv implementation on the 770.     The Xserver includes the
generic Xv layer implementation, and the libxv library exists, but
they do nothing for you... if your application uses the Xv API, it
will find "no adapters" because the meat of an Xv implementation is
completely absent.

The two core functions of Xv as far as most applications are concerned
are yuv->rgb conversion and scaling.

 For the yuv->rgb part, it is possible to allow the 770 lcd hardware
to display yuv directly.    This is done using the Linux fb layer,
bypassing the xserver entirely.    The is all on the arm side, and
does not involve the DSP at all.  I have done this in my code and it
is a major improvement.       Check out the mailing list archives, and
look at the omapfb.h file for mor information on this.

For the yuv scaling, your application needs to do it itself, or
perhaps you can get gstreamer to help you.  I investigated a solution
to do it on the DSP.  I got it working but the performance was far
from acceptable.  It was several times slower than doing it on the
ARM, and more importantly, it wasn't even fast enough to achieve real
time (i.e. ~ 30fps).   My plan was to combine this with the YUV fb
support to implement proper xv support for the xomap server, but with
the very poor performance, I gave up.

Hope this helps,

- -- Buck     

Corentin BARON wrote:

> Hello all,
> I'd like to know if anyone managed to install libXv and xvimagesink
> on the 770 or the same with SDL. That would be very helpful for
> us.
> Thx in advance, Corentin.
> ----------------------------------------------------------------------
> _______________________________________________ maemo-developers
> mailing list maemo-developers at maemo.org
> https://maemo.org/mailman/listinfo/maemo-developers

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