[mythtv-users] FE Stop/Restart for Smooth Playback [SOLVED]

[jim]

On 03/28/2015 01:20 PM, Stephen P. Villano wrote:
>
> On 3/28/15 1:17 PM, jim wrote:
>>
>> On 03/28/2015 12:51 PM, Stephen P. Villano wrote:
>>> On 3/28/15 12:29 PM, jim wrote:
>>>> On 03/28/2015 11:51 AM, Mike Perkins wrote:
>>>>> On 28/03/15 14:41, jim wrote:
>>>>>> On 03/28/2015 08:48 AM, Mark Perkins wrote:
>>>>>>>> On 28 Mar 2015, at 11:03 pm, "jim" <jim_32766 at hotmail.com> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> On 03/27/2015 10:21 AM, jim wrote:
>>>>>>>>> Occasionally, usually after the system has been running 24/7 for
>>>>>>>>> a few days,
>>>>>>>>> playback of recorded television shows is no longer smooth, with
>>>>>>>>> visible
>>>>>>>>> stutter where there should be smooth panning motion. Stopping and
>>>>>>>>> restarting
>>>>>>>>> the FE returns the playback to smooth operation. Has anyone else
>>>>>>>>> experienced
>>>>>>>>> this scenario?
>>>>>>>>> I have experimented with sync, cache drop, and swap stop/restart
>>>>>>>>> to achieve
>>>>>>>>> smooth playback without the FE stop/restart, but only the FE
>>>>>>>>> stop/restart
>>>>>>>>> seems to work. Any ideas or suggestions would be greatly
>>>>>>>>> appreciated. Thanks.
>>>>>>>>>
>>>>>>>>> System Info:
>>>>>>>>> 4 GB Ram
>>>>>>>>> i3 4330 CPU
>>>>>>>>> MythTV Version : v0.27.4-41-gf1115fc
>>>>>>>>> MythTV Branch : fixes/0.27
>>>>>>>>> Network Protocol : 77
>>>>>>>>> Library API : 0.27.20141016-1
>>>>>>>>> QT Version : 4.8.6
>>>>>>>> Based on receiving no answers it may be that nobody else
>>>>>>>> experiences this
>>>>>>>> problem. Please confirm if you do not.
>>>>>>>> My system is very modern, and has plenty of RAM. I wonder what
>>>>>>>> causes this
>>>>>>>> issue?
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>> I do not have this problem, my FE can be on for weeks or months at
>>>>>>> a time. But
>>>>>>> I have nvidia graphics, where I assume you use VAAPI.
>>>>>>>
>>>>>>> I would recommend starting by comparing the log file for a
>>>>>>> recording that
>>>>>>> plays fine with that of one that does not to see what the
>>>>>>> differences are.
>>>>>>>
>>>>>> If the difference were vaapi wouldn't the problem be present all the
>>>>>> time? I
>>>>>> wonder if something else running on my system contributes, or if the
>>>>>> OS (Mint
>>>>>> 17.1) is involved. What OS are you running?
>>>>>> I will also check the log file for a recording playback pre/post FE
>>>>>> start/stop.
>>>>>>
>>>>> Any problem like this doesn't automatically have to be continuous.
>>>>> For example, different programs may have different bit rates/frame
>>>>> rates/screen formats. These can impose differing demands on the video
>>>>> driver and hardware.
>>>>>
>>>>> The same also goes for audio, incidentally. If the audio encoding
>>>>> changes mid transmission - say for a commercial break - then that
>>>>> might cause buffering problems which could affect the vodeo.
>>>>>
>>>>> As Mark wrote above, your best bet is to look at the logs, a segment
>>>>> which works and a segment which is bad.
>>>>>
>>>> I use recorded Jeopardy! episodes for testing as the panning of
>>>> categories in Jeopardy! makes for a great test of smooth motion in
>>>> playback. When I test I use the same exact recording, pre and post FE
>>>> stop/start. The FE stop/start completely fixes the problem for some
>>>> inexact period of time. I've not done a good log comparison between a
>>>> smooth playback and a jerky one, and will do so as soon as the
>>>> problems appears again.
>>>>
>>>> I've never noticed a situation wherein the smoothness is better/worse
>>>> before/after a commercial break. I've experimented with SD and HD and
>>>> the full range of standard frame rates. None of that seems to stress
>>>> the system. If the FE has been recently stopped/started all
>>>> combinations are good. The problem behaves more like a buffer/cache
>>>> issue that builds over time and eventually causes a problem. Why FE
>>>> stop/start helps I do not know.
>>>>
>>>> I really appreciate the time people contribute on this mail list
>>>> answering questions. It really helps. Thanks.
>>>>
>>>> _______________________________________________
>>> Try running top during the post restart of the FE and during the poorly
>>> performing ones. That also might give you a clue.
>>> I've had to do that many times, a couple of times, process hogs turned
>>> up. Tuning or stopping unnecessary ones fixed the issue I was having
>>> (non-mythtv system, but the troubleshooting remains the same).
>>>
>>>
>> I removed MediaBrowser and Mono to see if that would help. I noticed
>> that Mono was high on the list from "top" most of the time, plus I've
>> read that there have been memory management issues with those
>> programs. I am still waiting for the problem to reappear so I can do a
>> log comparison pre/post. Thanks!
>> _______________________________________________
> If you're a lazy sysadmin, like I am, try htop. You can renice the
> processes that are offending to see if that helps.
> Of course, my ultimate laziness is more along the lines of scripting
> tedious chores.  :)
Just in case someone finds this thread in the future and can benefit 
from my experience, the jitter I was experiencing disappeared when I 
upgraded the kernel from 3.13.0-24 to 3.16.0-34. The newer kernel 
appears to make better use of the Intel HD4600 integrated graphics 
capability, and may have other improvements that help too. I tested for 
several days after upgrading the kernel before posting this response to 
make sure the jitter was really gone. Normally I would have encountered 
it several times by now and have not encountered it once.