[mythtv-users] LiveTV Stutters - Recordings are Perfect

[Josu Lazkano]

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
>> _______________________________________________
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>> mythtv-users at mythtv.org
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>
>
>
> 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