[Scottish] DVD - decode in software or hardware

Graeme Boyd scottish at mailman.lug.org.uk
Sat Jan 4 12:31:00 2003

Hi Gavin,

I used to watch DVD using a 300MHz IBM Thinkpad with WinDVD software 
decoding under windows without any problems so I see no reason why you 
shouldn't be able to get it to work.

I have used a program called Ogle under linux on a dual (intel) 500Mhz 
system and it worked flawlessly:
Ogle provides software only decoding.

Your graphics card makes a big difference to DVD playback speed if the 
software and drivers can make use of it, so it might be worth looking 
into whether you have the latest drivers and/or a change of software.

Finally, I have a system here which has a VIA chipset based motherboard 
(and a 433MHz proc).  Upgrading the bios provided a huge increase in 
speed so this is worth looking into.

Good luck!


On Friday, January 3, 2003, at 12:24  pm, Gavin McCord wrote:

> I'm setting up DVD on my system (detailed below), but it's pushing the
> hardware to its limits by the look of it, and I want to know whether I
> should try a hardware decoder.
> Hardware
> --------
> Monitor: CTX 1451
> Mainboard: Soyo 5EHM/5EH5 V1.x
> CPU: AMD K6-2 533 (running at 500)
> Chipset: ETEQ82c663 (VIA)
> Sound: AWE64 Value ISA
> Video: Nvidia Geforce 2 MX
> Samsung DVD ROM drive
> Software
> ---------
> mplayer 0.90rc2, SDL 1.2.5
>> From other newsgroup postings, and articles online I've read, my 
>> hardware
> setup isn't the best for this sort of thing, given the combination of 
> CPU,
> motherboard chipset and soundcard.
> However, I've enabled "VIA82CXXX chipset support" and
> "Use PCI DMA by default when available" in the kernel, and made
> sure, using hdparm, that dma is on for the DVD drive.
> My 14'' monitor is limited for practical purposes to one resolution,
> 640 x 480 @ 75Hz, so to be watchable, the image has to be resized
> using the SDL video output option.
> Analysing with vmstat, mplayer runs as follows (using the "nosound" 
> option):
>   When vo=sdl and display is fullscreen, CPU usage is around 93.
>   When vo=sdl and display is windowed (it's larger than the physical
>   screen size), CPU usage is around 84.
>   When vo=sdl:dga CPU usage is about 96, and quality is lower.
>   I've tried vo options of xv, x11 and the CPU usage is about the same 
> as
>   SDL windowed.
>> From what I've read a PCI soundcard should have less impact on CPU 
>> usage
> than an ISA one, but even so, I'm not sure there'd be enough leeway, 
> given
> that the lowest CPU usage I've obtained with mplayer is in the mid 80s. 
> When
> I have tried the sound, using "ao=sdl" or "aop 
> list=resample:fout=44100" (it
> needs to be downsampled from 48khz) it won't sync at all with the video.
> So, I'm tempted to buy a hardware decoder: the Creative Encore DXR2 
> (IIRC).
> But before I do, I just wonder if there's anything else I might try, to 
> lower
> the CPU usage and watch DVDs using only software decoding. (I've tried 
> low-latency
> patches with games, but I didn't notice any difference.)
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