[mythtv-users] Should I be switching to 0.21?

[Shawn Flynn]

On April 3, 2008 1:41 PM, Josh White wrote:
>
> On Thu, Apr 3, 2008 at 12:54 PM, Steve Peters - Priority Electronics
<steve at priorityelectronics.com> wrote:
>
>
>
>	>
>	>I'm also holding off in the hopes that the issues with excessive
CPU
>	>usage that keep being reported here will be fixed.
>	>
>	>I'll probably do what I usually do with Windows, and wait for the
.1
>	>release. ;)
>	>
>	>____________________________________________
>	
>	
>	
>	David, it's been my experience that the reason for the extra cpu
usage is
>	because the playback profiles give a higher quality playback. I was
using a
>	different deinterlacer on my mythbox with version 0.20.2, and my
playback
>	was not as smooth. I now use Yadif 2X, which I think is supposed to
be the
>	most cpu intensive, and during playback, my cpu is now at around 13%
for SD
>	Playback. It was at 10% before using kernel for deinterlacing. If I
go back
>	to kernel now on my 0.21 system, it goes backt o 10% cpu usage for
playback.
>	
>	I wonder if many people are saying they're seeing higher cpu usage
but are
>	not realizing that the playback profiles may be the reason. This is
an
>	improvement in my opinion because better playback is worth a few
percentage
>	points of cpu usage.
>	
>	-Steve
>	
>
>
>	_______________________________________________
>
> 
> I believe I have matched my settings on .21 to those I used on .20.2 and I
use more 
> cpu than I did before.  That was achieved by adding a simple playback
group that includes 
> only one setting, which is to use XVMC, openGL/openGL for the OSD, and no
deinterlacer.  
> All SD.  That's how I ran for months on .20.2 and there was no trouble at
all, and now that 
> I run that way on .21, my CPU usages is up 10-20 percent (the difference
between smooth 
> playback, quick channel changes, and smooth OSD to skipping playback, slow
channel changes, 
> jittery OSD on my 1.7ghz P4 frontend).  
> 
> I wish I could compare my two systems side-by-side, but I'm not going to
revert to .20.2 just 
> for the test.  
> 

I'll have to agree with Josh here. At least for me, the CPU requirements for
0.21 are a fair bit higher than they were for 0.20.2. I have an old Dell
GX50 that I use as a SD frontend (Celeron 1400, i810 displaying at 1360x768,
Centos 5.1 and atrpms mythtv packages). Running in 0.20.2 using ffmpeg/XV
and kernel-deint it would sit around 80% total cpu, which resulted in
perfectly smooth playback performance with a slight jitter during ffw/rwd
and osd fade. Switching to 0.21 using the 'slim' playback profile runs the
cpu at 100%. Even creating a custom playback profile using only
ffmpeg/XV-blit/no-deint/no-osd-fade (which should be the least cpu hungry of
any non-XVMC profiles) results in 100% cpu and a noticeable pause every 5-10
seconds during playback.

In my opinion, if you are running hardware that is close to the limit of
usability in 0.20.2, you probably should hold off on the 0.21 upgrade until
you are ready to invest in a hardware upgrade.

Shawn Flynn