[MPlayer-users] IS SMP support for X264 decoding possible

[Vladimir Mosgalin]

Hi Rich Felker!

 On 2006.09.19 at 12:57:59 -0400, Rich Felker wrote next:

> > > > >>I have some test 1080i h264 files that currently flatline a single
> > > > >>cpu, but should decode well if I could use all of a dual core.
> > > > >
> > > > >x264 doesn't decode at all. ffh264 is the decoder, and no it  
> > > > >doesn't support SMP.
> > > > 
> > > > Well, there's no reason that MPlayer still can't take advantage of  
> > > > some SMP stuff. For example: decoding audio on the second core, or  
> > > > applying any filters using the second core.
> > > 
> > > The reason is that it's slower except on SMP, impossible to debug, and
> > > just ugly.
> > 
> > Well, dual-core cpus rock modern desktops, and soon four-core desktops
> > cpus will come both from intel and amd... /me thinks argument about
> > beeing "faster" without threads doesn't apply anymore..
> 
> And I think you're full of it. Unlike idiot windows gamer kiddies, we
> do not assume everyone buys a new computer every year or even every 10
> years. 366 mhz is the baseline system for playing dvd now and, the

Sure, but everyone buys new computer because it needs one. Not everyone
has computer right now, you know. And 366 mhz may be enough for playing
dvd, but not for other tasks. If you just want to play dvds, sell your
computer, buy a dvd player and spend the rest of money ;)
Of course I don't think anyone would upgrade computer solely for playing
movies at better resolution - but there are a lot of reasons for
upgrading it. Both for performance purposes (even if user just wants to
have cpu-hungry background tasks not to mess up his movie) and for
features. Like wanting component HDTV output when there are no video
cards supporting it that would fit into your computer, or using /
developing an application that uses more memory than your computer can
handle, or having reasons for 64-bit system, or wanting gigabit lan for
accessing your remote storage (aka silent hard drive-less system) etc.

> lower we can move the baseline for playing h264, the better.

Try as you might, you won't have low requirements for 1080p or 1080i
video, unless of course you want to sacrifice all the quality..

> Also multi-core is just idiotic. It wastes power. The smartest use of
> a multicore system (aside from leaving it on the shelf) is leaving all
> but one core idle.

I think you should read more about modern cpus, why manufacturers have
started selling dualcore desktop cpus and so on. Believe me, on desktop
EVERYONE dislikes the idea of changing their application for multicore
support (and those windows game developers are probably first in the
line), but that's life. There is no other way. Increasing ghz even
futher on single-core cpus is stupid, pointless and impossible, unless
you'd like to have a huge computer case with very loud multi-cascade
phase-change cooling system and a mini power station at your home for
your pc. Unfortunately for you, most people prefer regular-sized cases
with quiet air coolers but still want faster cpus (or are forced to by
software developers, but that doesn't matter now), so they use multicore
cpus and SAVE power.

You can't make very fast single-core system. If you do, it would eat too
much power. You can have 2Ghz A64 processor, but you can't have 4Ghz one.
Well you can under phase-change cooling, but what's the point? You
wouldn't want to have that oven in your pc case. On the other hand, you
can have dualcore 2Ghz system and its power consumption would be similar
to 3Ghz singlecore system. But you'll get similar or even higher
performance than on 4Ghz CPU (it won't double, but neither it would on
4Ghz vs. 2Ghz system). Not to mention that it would be cheaper both than
3Ghz singlecore and than overclocking 2.4/2.6Ghz processor to 4Ghz.
Also there is no way you would have, say, 6Ghz A64 system, even with the
best cooling possible. However, 4x2.5 Ghz system would be much faster
than that and IS possible... Of course, software developers will
have extra problems, but there is simply no other choice.

If you are talking about power wasted when your system is idle, well
power-saving features of modern cpus are quite advanced. And they are
still advancing, four-core systems and future dual-core ones would have
separate power management for every core and would be able even to turn
on/off extra cores on the fly when they aren't used.

-- 

Vladimir