[mythtv-users] Jerky playback with ITV HD

T D topper.doggle at googlemail.com
Sun Jan 3 20:42:32 UTC 2010


2010/1/3 Another Sillyname <anothersname at googlemail.com>:
> 2010/1/3 T D <topper.doggle at googlemail.com>:
>> I'm running 0.22-fixes.  I have two boxes, each running a frontend and
>> backend.  One backend contains a DVB-S card which is pointed at 22.2E
>> for Astra and Eurobird (in particular "Freesat" services here in the
>> UK).  My CPU is an Athlon 64 X2  6000+, and I have an Geforce 8300
>> (the onboard version of the 8200) connected via HDMI.
>>
>> The main reason for having the DVB-S is that DVB-T in the UK doesn't
>> yet support HD, and I want to watch BBC HD and ITV HD.  Things mostly
>> work well, but ITV HD is flaky.  I've finally managed to tune it in,
>> but it's sometimes rather jerky.  My system is currently set to use
>> VDPAU Slim.  Also, I should say that BBC HD is problem-free on this
>> setup.
>>
>> So, with -v playback on ITV HD, I notice lots of:
>> 2010-01-03 14:28:10.285 Set video sync frame interval to 40000
>> 2010-01-03 14:28:10.285 Enabled deinterlacing
>> 2010-01-03 14:28:10.320 Set video sync frame interval to 40000
>> 2010-01-03 14:28:10.320 Enabled deinterlacing
>> 2010-01-03 14:28:10.352 Set video sync frame interval to 40000
>> 2010-01-03 14:28:10.385 Enabled deinterlacing
>>
>> I'm not sure what this means, but I don't see why it's happening 20-30
>> times a second.  I am guessing that anything occuring this often could
>> be enough to make the ITV HD playback jerky, but I don't know what to
>> do about it.  For what it's worth, I tried changing from VDPAU Slim to
>> (non-VDPAU) Normal, and the jerkiness went, but there was a blurriness
>> instead, CPU utilization was up to 90%, and the "Set video sync frame
>> interval to 40000" messages vanished although the "Enabled
>> deinterlacing" was still present.
>>
>>
>> Can anyone provide advice on how I should debug this further?
>>
> I realise this is counter intuitive but have you tried turning logging off?
>

I only turned verbose logging on in the first place to see what the
problem was.  It's was jerky before I turned the logging on.  I don't
think that it would write so much to the log if all was running well -
why would it need to /keep/ enabling deinterlacing?  Even if this
message isn't related to the issue, I need to know why it keeps
appearing.

> I've seen situations in the past where the log files being created
> were causing issues as they were getting written to disk (because so
> much info was being written).
>
> Also if your using a multi core system have you set playback profile
> to use all the cores?

Not yet, although I'm not sure that matters with VDPAU, as my CPU is
barely stressed at all.  I'll try it though - it's pretty easy.

-- 
TD


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