[mythtv-users] Playback problem -- random short pauses

[Steven Adeff]

On Sun, May 22, 2011 at 9:42 AM, Phil Wild <phil at holobyte.com.au> wrote:
> On Wed, May 18, 2011 at 3:53 AM, Mark Boyum <mark at boyum.us> wrote:
>> > I've been using the 260's without much issue.
>> > 256 was a bit more stable, but for some reason I couldn't get
>> > flash/vpdau/boxee to compile properly/work properly with 256, so I took
>> > the plunge to 260.  BTW this is on gentoo 2.6.34-r12.
>> >
>> My combined frontend / backend experiences slight pauses as well.  I
>> have attributed them to recordings starting or ending while we are
>> watching by simple observation when they occur.  i.e. Pause happens,
>> check HDHR LEDs to see a tuner is now active.  Next pause happens and
>> the LED is now off.
>>
>> Has this been confirmed as a MythTV issue or could it be a kernel
>> update or something?  I ask as I am still running .23.1-fixes and
>> experience the pauses on Ubuntu 10.04 (32-bit).  Not at my machine now
>> so I can not provide specific software versions.
>>
>> -Mark
>> _______________________________________________
>
> I have been following this thread as I am also experiencing these pauses. Re
> the comments about it possible relating to hard drive performance, isn't the
> idea behind the ringbuffer supposed to get you through these little IO
> glitches. I have tried increasing the ringbuffer to see if it makes any
> difference and it doesn't. I currently have the ringbuffer set at 48Mbytes
> (from memory) and it appears to make no difference.
> I suspect it may be something else other than hard drives that are causing
> the issue. I run with a frontend that boots from a USB stick with no local
> hard drives.  Can someone with more knowledge on how myth works fill in the
> gaps. With the ringbuffer set to some value, does that mean that the
> frontend has this amount of data in reserve when playing recordings or video
> (via storage groups)? If this is the case, then one would expect that large
> amounts of processing on the backend (recordings starting/finishing, mysql
> work etc) should not impact a playing stream on the frontend. When a video
> stream is playing, is there any other data stream (like some sort of control
> data) going to the frontend that could impact the playback if this other
> data stream was interrupted?
> Comments?

Has anyone checked the SQL usage? if the ringbuffer setting isn't
affecting things, perhaps it's SQL that needs to be accessed faster?
Perhaps we need to start looking into SQL tweaks?

-- 
Steve
http://www.mythtv.org/wiki/User:Steveadeff
Before you ask, read the FAQ!
http://www.mythtv.org/wiki/index.php/Frequently_Asked_Questions
then search the Wiki, and this list,
http://www.gossamer-threads.com/lists/mythtv/
Mailinglist etiquette -
http://www.mythtv.org/wiki/index.php/Mailing_List_etiquette