[mythtv-users] LiveTV Stutters - Recordings are Perfect

[Mitch Capper]

mythpreviewgen may be decently easy to debug look at the log output for it.

~Mitch

On Tue, Jun 12, 2012 at 6:17 AM, Josu Lazkano <josu.lazkano at gmail.com> wrote:
> 2012/6/12 David Hofstra <dave at dhofstra.com>:
>> On Mon, Jun 11, 2012 at 4:50 PM, Karl Newman <siliconfiend at gmail.com> wrote:
>>>
>>> On Mon, Jun 11, 2012 at 12:54 PM, David Hofstra <dave at dhofstra.com> wrote:
>>> > I'm a long-time MythTV user, but I've only ever used Myth to watch
>>> > recordings (not to watch live-tv).  I've always used my DirecTV box for
>>> > LiveTV as it was easier for the WAF.
>>> >
>>> > I recently purchased a HDHomerun Prime, and switched from DirecTV to
>>> > Xfinity.   I found that the Xfinity box on-screen guide is unbearable to
>>> > watch LiveTV... ughh  So, I'm trying to use MythTV to watch LiveTV and
>>> > ditch
>>> > the Xfinity box altogether.
>>> >
>>> > Problem:   Recordings playback wonderfully 100% on my frontend (and have
>>> > for
>>> > years).  LiveTV stutters about 10 times per hour, and about once per day
>>> > it
>>> > fails.   It almost always stutters a few seconds after the channel
>>> > change,
>>> > which I hear is to be expected, but then it continues to stutter every
>>> > so
>>> > many minutes.
>>> >
>>> > A)  When LiveTV fails, it fails with 'video buffering failed too many
>>> > times'
>>> > B)  When LiveTV stutters, I see a bunch of the following in the frontend
>>> > terminal (infact, I see this when it doesn't stutter also)
>>> >      -RingBuf(<filename>): Waited 0.2 seconds for data to become
>>> > available... 15720 < 32768
>>> >      -RingBuf(<filename>): Taking too long to be allowed to read..
>>> >
>>> > I have a Geforce 210 @1024MB running 295.40 and it is using VDPAU normal
>>> > settings on mythbuntu (OS 12.04)
>>> >
>>> > Here's what I have tried so far:
>>> >
>>> > 1)  Replaced network cables to HDHomerun Prime as well as to the
>>> > frontend.
>>> > 2)  Replaced the hard-drive in the frontend.
>>> > 3)  Moved the LiveTV recording group directory to a faster RAID5 drive
>>> > set
>>> > on the backend (previously on home directory)
>>> > 4)  Stopped upmixing stereo to 5.1
>>> > 5)  I tried both streaming using the myth:// protocol, and also having
>>> > the
>>> > liveTV directory on the NFS share directly.
>>> > 6)  I tried using every window manager known to man
>>> > 7)  Upgraded to the newest 0.25 mythtv-fixes, which updates to a new
>>> > version
>>> > virtually every day
>>> > 8)  I have one other frontend with a Geforce 6150, and while it doesn't
>>> > seem
>>> > to stutter, the HDTV tearing is so horrible, I cannot really tell if
>>> > this
>>> > box has the same problem or not.
>>> > 9)  I've increased the HD ringbuffer size in the backend-setup
>>> > 10)  Some folks note that if you pause LiveTV for a few seconds, then
>>> > the
>>> > stuttering stops.   This also seems to work for me, but I hate to have
>>> > to
>>> > pause LiveTV every time I change the channel.
>>> >
>>> > Does anyone have any other thoughts, or notice something I have not
>>> > tried
>>> > after looking the above over?  Why/How could Recordings be so perfect,
>>> > and
>>> > LiveTV be so horrible????  Any suggestions appreciated.
>>> >
>>>
>>> What about Playback -> Extra Audio Buffering? I had similar symptoms
>>> (although much more frequent than 10 times per hour) and this setting
>>> smoothed out Live TV for me with VAAPI on Intel.
>>>
>>> Karl
>>> _______________________________________________
>>> mythtv-users mailing list
>>> mythtv-users at mythtv.org
>>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>>
>>
>>
>> I did check, and extra audio buffering is on.   Thanks for the suggestion.
>> I've also fiddled with realtime priority threads, neither of which seem to
>> really help anything.
>>
>> I'm perplexed as to why pausing for a brief second seems to fix the LiveTV
>> problem.   I keep wondering what the "HD Ringbuffer size" in the backend
>> is... is that a way to set a large enough buffer for LiveTV?
>>
>> If a recording is going on, and I watch another recording at the same time,
>> it is perfect, why would LiveTV be any different than this scenario?
>>
>>
>>
>
> I have same problem with my FE/BE Atom machine.
>
> I think is something related to tv program change, it start the
> mythpreviewgen and get 100% CPU.
>
> Hope someone will fix it soon.
>
> Best regards.
>
>
> --
> Josu Lazkano
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