[mythtv-users] HD playback slight jitter every 10 secs

[Angela]

>On Tue, Feb 11, 2014 at 8:04 AM, Monkey Pet <monkeypet at gmail.com> wrote:
>On Mon, Feb 10, 2014 at 1:45 PM, Angela <angela.schmid at wolke7.net> wrote:
>Have I look at https://code.mythtv.org/trac/ticket/12016 which discusses
>jitter with viewing in-progress recordings.
>
>My issue happens on non in-progress recordings also.  The backend is
completely idling (no mythfrontend jobs / recordings) and it still happens.
 I watched the stats during playback on the remote frontend and nothing
suspicious seems to happen >with the framerates/buffers/decoder during the
jitter.  However, it happens so fast, it is hard to tell.

Select menu/playback/playback data and watch the FPS, drops as much as 3-5%
are already noticeable. Also watch A/V sync. 
I had drops from FPS 50 to FPS 18 with in-progress recordings, this stalls
about 0.5 seconds.

>I switched from kernel 3.11.0-15-generic to 3.13.3-lowlatency and that
solved my issue. I didn't try the 3.13.3-generic, so I don't have that to
compare.
Would be interesting to hear from others it the lowlatency kernel does a
better job. 
How many cores do you have?  

About a year ago I had problems like discussed right now in the
ringbuffer.cpp thread on the dev list. I upgraded to a newer kernel 3.9
(from 3.6 or 3.7, don't remember). I compile my kernel myself, as I need to
integrate a DVB-C driver (ddbridge). As I needed to configure the kernel for
several drivers in the next days (network, wifi, iptables modules, etc.) I
understood later that the old .config was not used from the beginning and I
started with a "fresh, minimalized" .config  (tried to verify the history
for "make oldconfig", but didn't survive a reboot). This stabilized my
system. 

Angela