[8] Linux vs Windoze

[Doug Wolfgram]

Thanks for the info. I have a question...

I am not too expert on compiling and running apps in Linux. I was under
the impression that VLC required SDL to run. Is that not so?

Doug


On Mon, 2001-11-26 at 11:32, kevin at ank.com wrote:
> There are probably several factors.  Depending on the video card you
> use, you may or may not have full acceleration support from XFree86.
> Using a commercial X server like AcelleratedX would fix this if that
> is the problem.  
> 
> Secondly, your CPU may not be well optimized under Linux; commercial 
> compilers often generate executables with performance that is up to 
> twice as good as GCC.  GCC is not optimized at all for the AMD Athlon, 
> and only somewhat optimized for Pentium III and higher.  Instruction 
> scheduling plays a huge role in how well exectuables perform on the 
> most recent chips, so using a commercial compiler or some of the newer 
> experimental open source compilers like PGCC, and AthlonGCC to compile 
> vlc may help these problems.  
> 
> Lastly, using SDL isn't the best choice for rendering Video data.  X11
> comes with many protocol extensions, some of which are better and some
> worse at quickly rendering lots of bitmap data.  The core protocol is
> quite poor, but using XFree86 4.0 you can instead use the XV extension 
> if your graphics board is one of the ones for which an XVideo driver 
> has been written.  For boards without XV support there are some tweaks
> that you can do to speed up X11 by 10% or so, such as setting up the 
> MTRR registers correctly.  
> 
> For what it is worth, vlc on my P-II 750 notebook is quite smooth without
> any of the optimizations mentioned above.  My desktop is a 1.4GHz Athlon
> that is mostly smooth with occasional hiccups with an XV supported 
> video card (the GeForce3).
> 
> Cheers,
> -kls
> 
> On Mon, Nov 26, 2001 at 09:55:25AM -0800, Doug Wolfgram wrote: 
> > Now that I have vlc running on the same machine in both Windows 2000 and
> > Linux (RH7.2) I was wondering if someone could explain why the Linux
> > version is choppy and the video gets out of sync with the audio.
> > 
> > Is this the difference between SDL and DirectX? Is it correct to assume
> > the same basic codec is used for both and that the video performance
> > difference is in the video device drivers and such?
> > 
> > Any help would be enlightening. I'd like to stay on the Linux side, but
> > the video doesn't play smoothly. 
> > 
> > D
> > 
> >  
> > -- 
> > 
> > Doug Wolfgram
> > Principal
> > CTO Partners
> > www.ctopartners.net
> > partners.net
> > 
> > 
> 
> -- 
>           //                               .--=,
>  .....::://::::::::::::::::::::::::::::.. (o O &           kevin at ank.com
> :::::::://:::://://://:/:://::||_//       / V  K   
>  :::::://:::://:/:|//'/' // _,|'         r ,  'qk   
>   :'''/____ // /  //  |_// // ||        .'~.  .~`, 
>                                    kls   \_/-=\_/
> 
> 
> 
-- 

Doug Wolfgram
Principal
CTO Partners
www.ctopartners.net
partners.net