LiViD   Performance How To UserPreferences
 
Help Search Diffs Info Edit Print View
 MoinMoin Wiki   LividWiki   RecentChanges   TitleIndex   WordIndex   Help 

The following 119 words could not be found in the dictionary of 581 words (including 581 LocalSpellingWords) and are highlighted below:
0x00000000   0xe2000000   0xe4000000   Buy   Compare   Compiling   Configure   Contents   Disk   Don   Meg   O3   Once   P2   Rage128   Setup   Something   abuse   accelerated   accessed   accessible   additional   alsa   arguments   bit   break   certain   cheap   cheaper   check   clicks   combining   command   console   count   d1   debug   details   determine   dev   devel   disk   disks   faq   few   filesystem   first   flags   foo   fr   frame   framerate   give   go   goemon   greater   hda   hdparm   hit   impact   important   inria   jumped   lamp   large   let   listening   located   look   lots   machine   maybe   modes   money   mpeg   mpeg2dec   mpg   mtrr   much   my   new   noise   optimizations   painfully   parallel   pauillac   phosphore   pops   power   proc   processing   processor   properly   rate   read   really   reduced   reg00   reg01   reg07   registers   seems   similar   slow   something   soundtrack   spew   still   such   than   they   throwing   waiting   want   write   xdpyinfo   xvinfo   xvshm   yourself  

Clear message

Contents:

  1. Hardware
    1. Faster Hardware
    2. XVideo
    3. MTRR Setup
    4. DMA Disk Access
    5. AUDIO Performance
  2. Software
    1. Find the Problem
    2. Compiling

Hardware

Faster Hardware

Buy faster hardware!

Yes, throwing money at the problem will help.

Memory is important. So go get phosphore. I just upgraded my machine from 64Meg to 96 Meg, and the (Mpeg2Dec) framerate jumped from 17 to 25 fps. Sure, my machine is slow (P2/233), and I'm really waiting for an accelerated mpeg driver for my Rage128 (see GatosProject), but if you have only 64 Meg, add some more memory... JeremyErwin

XVideo

Use XVideo if possible. This is supported in XFree86 4.0.x or greater for some video cards. See HardwareCompatibility.

Run xdpyinfo and look for XVideo extension.

Run xvinfo to see supported modes.

MTRR Setup

For details on how to do this, check the LAMP FAQ located at http://pauillac.inria.fr/lamp/faq.html

This could dramatically boost your mpeg decoding performance:

Configure the MTRR registers (/proc/mtrr) so that your frame buffer is accessible in write-combining mode. If you have XFree 4.x, this is done automatically, but with XFree 3.x you have to do it yourself. Once your MTRR registers are properly configured you should see something like this : 

# cat /proc/mtrr 
reg00: base=0x00000000 (   0MB), size= 256MB: write-back, count=1 
reg01: base=0xe2000000 (3616MB), size=  32MB: write-combining, count=2 
reg07: base=0xe4000000 (3648MB), size=  64MB: write-combining, count=1

DMA Disk Access

If you use IDE disks, make sure they are accessed in DMA mode, not PIO. PIO is still the default, but it is a very large performance hit, because it does not let your system work on mpeg decoding and read from the disk in parallel. Make sure you run a command similar to hdparm -d1 /dev/hda. You will probably need additional arguments, and please read the man page first because you can break your filesystem if you abuse this command.

AUDIO Performance

If you have certain audio cards (I have a ESS 1938 PCI card) using the ALSA drivers seems to help quite a bit. The kernel module for audio made listening to the soundtrack painfully full of pops and clicks. Loading the ALSA driver for reduced my audio noise to ZERO.

ISA sound cards also can have impact on the performance, because ISA DMA seems to need some processing power. Upgrading to a cheap PCI sound card can give you a few fps and is cheaper than a new video card. See [WWW]http://www.alsa-project.org/~goemon/ for a list of ALSA-supported cards.

Software

Find the Problem

One way to determine if your processor is fast enough to decode video is to run Mpeg2Dec (or maybe OpenMediaSystem) with no video output. If the frame rate is much higher than with video enabled then your problem is the video driver or video hardware.

Something like this: mpeg2dec -o null foo.mpg. Compare framerate with mpeg2dec -o xvshm foo.mpg (or whatever driver you want).

Also see PerformanceResults.

Compiling

PythonPowered EditText of this page (last modified 2001-06-01 15:24:01)
FindPage by browsing, searching, or an index
Or try one of these actions: LikePages, SpellCheck

MoinMoin 1.108, Copyright © 2000-2001 by Jürgen Hermann

spellread = 0.030
config = 0.000
total = 1.130
imports = 0.610
spellcheck = 0.090
send_page = 0.190