Raphael Pooser wrote:
Michael T. Dean wrote:
[...]
Have to ask because I have never been able to figure out what the
difference is: What is the difference between xv and xvmc. I read
somewhere that xvmc is a hardware thing while xv is jsut somekind of
software extension. But if that were true, than why is xv dependant
on the graphics card driver at all? The ati cards can use xv, but not
xvmc, why is that, and is there a giant performance difference between
the two? I read on this list a guy using xvmc with an nvidia card
taking 2-3% proc time in X to run a 720x480 stream, which is exactly
how much is takes using xv with an ati card? Would it take even more
using xv and not xvmc? Sorry for the seemingly obvious to answer
question. My friend is getting ready to builf a myth box using nvidia
and as I use ATI I want to make sure I have enough knowledge to help.
XV is efficient software decoding.
XVMC is hardware assisted software decoding.
On my nvidia 5200 + Celeron D @ 2.93ghz + 1Gb DDR 3200 RAM, normal mpeg2
playback takes about 13-15% CPU using XV.
Using XVMC, it takes between 8-10% CPU. So no, it's not a dramatic
difference unless you're using a low power CPU like a 733mhz
P3.
I don't even bother with XVMC for three reasons:
1.) The OSD is GRAYSCALE for some reason. (is this fixed in SVN yet?)
2.) FF, Rew, Next, and Prev cause about 5-10 seconds of jitter and
skipping when using XVMC.
3.) Even without any sort of de-interlacing turned on, I get really bad
flicker on the OSD.
For example, when I change the volume the OSD volume bar is
unintelligible it flickers so much.
Also, note that it really is just hardware assist. It's nothing like the
PVR 350's hardware playback.
With the 350, I could max out my CPU and compile code in the background
while watching a show
without any skipping, jitter, etc. With the nvidia card it doesn't
matter if I use XV or XVMC, I always
get some skipping and jitter while compiling code in the background or
burning a DVD. (would a real
P4 with HT enabled solve this?)
If the jitter, flicker, and grayscale problems could all be eliminated
then XVMC would kick-a**, but
as-is it seems rather pointless on my hardware.
--
Jesse Guardiani
Programmer/Sys Admin
[EMAIL PROTECTED]
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