[mythtv-users] Prebuffering pause on Frontend playing back HD

Chris Dos chris at chrisdos.com
Sun Dec 31 02:07:59 UTC 2006


I built a new frontend for Christmas.

It's spec's are:
AMD X2 3800+ proc
Asus M2NPV-VM MB with Integrated Geforce 6150 Video VGA/DVI
1 GB RAM
Silverstone ML01 case
etc.

This was pulling off 802.11a at a sustained 4 MB/s transfer, but for testing
this issue, I've hooked up GB ethernet and I'm transferring 23 MB/s.

The combo backend/frontend that is in the family room plays HD fine.  This
frontend was imaged from the backend and necessary changes made to make it just
a frontend.  Hardware is mostly the same between the backend and the frontend
except the backend has a AMD X2 4200+ proc and a lot more hard drives.

I've configured the fronted to use NFS and tired it without NFS.

Processor usage on the Frontend during playback is around 40%.  Output from top:
PID   USER      PR  NI  VIRT  RES  SHR S %CPU %MEM   TIME+   COMMAND
23932 mythtv    15   0  470m 359m 122m S  109 40.8   6:17.23 mythfrontend

21978 root      16   0  350m 341m 108m R   14 38.7   1:10.29 Xorg

I'm using libMPEG for playback, but standard has the same issue as well.


The prebuffering pauses look like the following:
'video_output' mean = '42568.11', std. dev. = '57287.23', fps = '23.49'
2006-12-30 18:47:49.782 NVP: prebuffering pause
2006-12-30 18:47:49.782 NVP: Waiting for prebuffer.. 0
AAAAAAAAAAAALLAAAuAALAAAAAAAAAA
2006-12-30 18:47:49.921 NVP: Waiting for prebuffer.. 1
AAAAAAAAAAAAUUAULUAAuAALAALAAAA
2006-12-30 18:47:50.061 NVP: Waiting for prebuffer.. 2
AAAAAAAAAAAAUUAUUUUUUAAuAALAALA
2006-12-30 18:47:51.569 Avg read interval was 198 msec. 416K block size

I'm running SVN 12277 on both the backend and frontend.


So I'm at a bit of a loss on where to go from here.  Everything "should" work.
This is the first frontend that I've built that I've designed to playback HD and
so far I'm pretty confused about why I'm getting the prebuffering pauses.  SD
plays back flawlessly.

HD Playback has been working fine on the combo backend/frontend in the family
room for the last 18 months, so I'm a bit of a loss on why it's not working with
this frontend that has similar specs.

	Chris




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