[staticx]

Hi
When I play HD content, XBMC is dropping frames and causing the audio and video to de-synchronize.

take a look at the video
http://tinypic.com/player.php?v=vyxh69&s=4

is there a way to solve this?

tx

[marlboroman1]

that seems odd as your cpu doesn't aper to be maxing out probably best to check the task manger to confirm your not getting 100% cpu usage as xbmc readings are not always accurate.

posting your system specs, video codec, resolution, debug log and sample may help resolve the issue

as a rule of thumb you need a fast modern cpu for HD 2 ghz dual core for 720p and 3 ghz for 1080p you can get away with less but not for all encodings

[staticx]

My specs are AMD Athlon 64 X2 4850
2 GB DDR2-800 4-4-4-8
ATI HD3200 ONBORAD
500GB SEAGATE SATA2 7200RPM 16MB
RESOLUTION 1920X1080 (1080P)

I can tell you that in BSPLAYER or PowerDVD8 the cpu is between 20% - 60% (works smoothly) , and in XBMC it's 60% - 99% (losing frames).

[marlboroman1]

I think Powerdvd has hardware acceleration's so it would out perform XBMC which has non. seems likely that your running out of cpu power on hight bitrate scenes.
if you think this is not the case provide a debug log and a sample so others can see if its reproducible.

[Cam73]

I had the same problem on my HTPC.

Origianlly it was Penitum Dual Core 2.0GHz with a GF8600GT video card.

Playing HD content through PowerDVD worked perfectly..as it utilised both cores of the CPU and offloaded some processing to the GPU.

At this stage XBMC does neither of these things... it will only use one core and doesnt offload to the GPU.

So my Pentium Dual Core 2.0GHz just wasnt fast enough... I could see the CPU usage hitting 50% and staying there (it was maxing out one core to 100%..which is 50% of the total).

All i did was drop in a Core2Duo 3.33GHz CPU and the problem is gone - i get flawless 1080p playback.

[zAo_OSX]

I have the same problem with a E7200 (2.53ghz C2D). Usage is around 30% but still losing frames.

[staticx]

Cam73, do you think that amd athlon x2 5400+ will solve my problem? or the difference between 4850e and 5400+ is not very noticeable?

[Cam73]

Cam73, do you think that amd athlon x2 5400+ will solve my problem? or the difference between 4850e and 5400+ is not very noticeable?

What CPU percentage does Windows Task manager report when playing HD content?

If like zAo_OSX it is only 30% then an under speed processor isn’t indicated.

What I would do is...
Run XBMC in windowed mode
Run task manager and change to the performance page
Start a high def movie and watch CPU usage.
If you find that the CPU is at 50% (or close to) at least some of the time then a faster processor is a good bet.

Even if the average CPU usage is lower than 50% it is the peak usage that matters - variable bitrate content will take varying amounts of CPU to decode and display.

Also don’t be fooled by the CPU graphs... although XBMC will only use 1 core at a time it will potentially use both cores as determined by the OS. So what I mean is that you may see that both cores are running at 25%... that is still 50% overall. I assume that XMBC is not multi threaded (yet) so it can only use 1 core at any point in time...but as windows schedules CPU usage it will assign XMBC to one or the other of the available cores based on some internal algorithm.

In my case before I changed CPU I was getting about 35% on one core and 15% on the other, but the total was 50%.

[staticx]

ok I'll check it and will post back soon
I have another problem now... I've connected the computer via HDMI, the sound and video goes thru there. my point it, that when I play movie via BSPLAYER, I can hear. but when I play via XBMC no sound is coming out... as if it's not supports the hdmi out port...

[Cam73]

ok I'll check it and will post back soon
I have another problem now... I've connected the computer via HDMI, the sound and video goes thru there. my point it, that when I play movie via BSPLAYER, I can hear. but when I play via XBMC no sound is coming out... as if it's not supports the hdmi out port...

I find audio over HMDI to be a bit hit an miss for PC based solutions - works perfectly with Consumer Electronics though.

I run a HDMI cable from my HTPC to my receiver, but i also run a digital audio cable...since then i havnt had any troubble. I know this shouldnt be necessary, and isnt ideal...but we are on the bleeding edge of technology...