[vlc-devel] Re: Question about HD play

Sigmund Augdal sigmunau at stud.ntnu.no
Thu Feb 5 09:49:23 CET 2004

I have some questions:

> In documentation (VideoLAN client API) 4.6, it say VLC provides just an MP at ML decoder for MPEG-2. Is this description valid until now?
4.6? perhaps you mean 0.4.6? In that case vlc has droped it's internal mpeg2
decoder in favor of using libmpeg2. This was because libmpeg2 turned out to
be considerably faster, and also better in many other ways.
> I already tested HD streaming that has 20Mbps bandwidth. Spec of test systems run as follows; 
> maching for VLC
> processor: ZEON 2.0 ( dual )
> memory: 1G byte
> video: ATI FireGL E1 64Mbyte (dual)
> os: winxp
> display resolution: 2560 * 1024 (two monitors)
Are you running two windows (using wall-filter or some other filter combo)
or do you have one window streching both monitors?
> Test succeeded somehow. - good decoding, just few lost pictures but too much occupation of  system resource.
What system resources? CPU? memory? io? My laptop has a P4M cpu at 2ghz, and
it is far from able to decode such a stream. But my 1.8ghz athlon XP can
decode it fine. I talked with the libmpeg2 author and he thought perhaps it
has something todo with L1 cache. Do the XEON have more L1 cache than a P4M?
> However, quality of display is not fine. It is main problem. 
I guess this is because the stream is interlaced and you didn't enable the
deinterlace filter. This is available from the video menu in the windows
gui. I suggest the "blend" mode for best speed/qualty tradeoff. Note that
this will add a considerable extra cpu usage.
> Is it possible to optimize VLC as my objective? So,  Can I acquire fine quality screen?
I doubt there is much to do. I've implemented some sse2-acellerations for
the deinterlace, perhaps they will help (downlaod latest nightly build from
download.videolan.org/~videolan/build to test). Except this, I don't see any
easy optimizations.

Sigmund Augdal

This is the vlc-devel mailing-list, see http://www.videolan.org/vlc/
To unsubscribe, please read http://developers.videolan.org/lists.html
If you are in trouble, please contact <postmaster at videolan.org>

More information about the vlc-devel mailing list