[Theora] problems understanding yuv_buffer format

[Aaron Whitehouse]

Hi David,

> what i want to achieve is getting the Y, U and V data for each single
> pixel, so i can convert it to one R, G and B value.
> 
> i am trying to apply one of the conversion formulas presented at
> http://www.fourcc.org/fccyvrgb.php, but as of now was never successful
> since the description of the buffer format doesn't help me getting the
> idea....

If you are talking about designing an implementation, perhaps GStreamer
(http://gstreamer.freedesktop.org/) could help. I don't really know
enough about this, but saw some good comments on:
http://sourceforge.net/mailarchive/forum.php?forum_id=5947&max_rows=25&style=nested&viewmonth=200402

Find the thread on 'colorspace conversion' and you'll have a start; if
nothing else some people to ask. They seem to refer to some other
projects which may be of use to you. The thread is a bit old, however,
so some of the things which they are talking about may be in existence now.

Perhaps liboil may be of interest:
http://www.schleef.org/liboil/desktopcon-2005.pdf

Even
http://lists.matroska.org/pipermail/media-api/2003-December/000265.html
may be of some use.

As I say, I don't really know this area, but it seems more sensible to
me to have a generic GST YUV -> RGB converter and just construct a
pipeline from the GST-Theora plugin to the converter.

Hope that helps,
Aaron