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View Full Version : DVD playback differences betweeen hardware and software decoder


J.Clarke
July 16th 03, 08:38 AM
On Wed, 16 Jul 2003 11:51:37 +0200
"ValGLA" > wrote:

> Hi,
>
> What are the differences playing DVDs using decoder with hardware
> acceleration or only by software ?
> May be image quality or cpu usage, playing with?
>
> I tested players like windvd or nvdv.
>
> Thanks for the answers.
> My PC:
> XFX 5200, detonator 44.71AMD XP2000+
> 512 DDRAM PC2700

With the software decoder all the processing is done by the CPU. This
may, depending on the particular hardware decoder, give you better or
worse quality than using the hardware decoder. OTOH, the hardware
decoder should give less load on the CPU, if you are doing other things
at the same time that you are watching DVDs that will make a difference,
otherwise not.

--
--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

ValGLA
July 16th 03, 10:51 AM
Hi,

What are the differences playing DVDs using decoder with hardware
acceleration or only by software ?
May be image quality or cpu usage, playing with?

I tested players like windvd or nvdv.

Thanks for the answers.
My PC:
XFX 5200, detonator 44.71AMD XP2000+
512 DDRAM PC2700

Stephen Smith
July 16th 03, 11:00 AM
"ValGLA" > wrote in message
...
> Hi,
>
> What are the differences playing DVDs using decoder with hardware
> acceleration or only by software ?
> May be image quality or cpu usage, playing with?
>
> I tested players like windvd or nvdv.
>
> Thanks for the answers.
> My PC:
> XFX 5200, detonator 44.71AMD XP2000+
> 512 DDRAM PC2700
>

Well in my experience with PowerDVD 3, I find that movies play much
smoother fullscreen @ 1600x1200 with hardware acceleration DISABLED than
they do with it Enabled! I also see no particular heavy usage of the CPU
either, and the picture quality looks no different.

P4 1.5GHz, 512MB RIMMs, Detonator 41.09, (yep, they play DVDs!) Hercules
Prophet III

Stephen.

magnulus
July 16th 03, 03:55 PM
"jon l" > wrote in message
...
> Odd, but don't anamorphic dvd's default to a higer resolution. I opened
one
> and it's
> default window was much larger than 800*600.

I think anamorphic DVD's contain more information horizontally. The
picture is squeezed, similar to anamorphic film, and when you play it back,
it unsqueezes it. The whole idea is provide more information for
widescreen viewing on a larger TV.

When you play an anamorphic DVD at NTSC resolution, it drops every 4th
line. So many DVD's now days are anamorphic, though, that I have trouble
checking to see if it actually makes a difference vissualy on a PC monitor.
One thing is for sure though, a PC monitor provides a much clearer image
than the average TV, for watching movies.

Stephen Smith
July 18th 03, 07:31 PM
Bob Byrne said:

> Stephen Smith > wrote:
>
> > Well in my experience with PowerDVD 3, I find that movies play much
> > smoother fullscreen @ 1600x1200 with hardware acceleration DISABLED than
> > they do with it Enabled! I also see no particular heavy usage of the CPU
> > either, and the picture quality looks no different.
> > ....
>
> I also notice no difference and as you have to have it disabled to capture
> frames I leave it off.

Yep.

> Stephen, why 1600x1200?

That is the resolution this PC runs in.

ah, I see what you mean...

"I find that movies play much smoother fullscreen @ 1600x1200 with hardware
acceleration DISABLED than they do with it Enabled!"

What I wrote can be misinterpreted. I find that DVDs play smoother with
hardware acceleration disabled, compared to when it is enabled. Period.

They don't "perform better" with the hardware disabled *exclusively* in
1600x1200, if that is what you were thinking. Sorry for the confusion. :-)

(1600x1200 is in no way "a magical optimal resolution", etc, it's just that
I'm too lazy <g> to switch to anything lower, and I see no degrade in
performance leaving it in this resolution fullscreen)

Stephen.

Bob Byrne
July 22nd 03, 03:45 AM
Stephen Smith > wrote:
> Bob Byrne said:
>> If I use a high res and full screen the image degrades a lot.

> :-( I have absolutely No idea what is causing that. Is it just MPEG 2
> artifacts that you're seeing "magnified" or some other degradation?

It probably is and I'm not necessarily unhappy about it just surprised that
you have such a good picture. As you say it is just MPEG2 and DVD's
use 720x480/(576 PAL) so one would think by stretching that resolution
to 1600x1200 the image would become pixellated.
Run any low quality video (asf, wmv etc) in Windows Media Player then
enlarge it by 200% (Alt-3) and you will see what I mean.

--
Bob
>