[mythtvnz] Pixelation/Corrupt recordings

[Curtis Walker]

On 7 July 2014 13:19, Aaron Pelly <apelly at monkeymasters.co.nz> wrote:
> On 07/07/14 12:21, Steve Hodge wrote:
>
> On Mon, Jul 7, 2014 at 12:08 PM, Aaron Pelly <apelly at monkeymasters.co.nz>
> wrote:
>>
>> On 07/07/14 11:23, Steve Hodge wrote:
>>>
>>> If it's not consistently happening with simultaneous recordings it's
>>> probably not a throughput issue. You could try recording say 6 things at
>>> once to test this.
>>
>> You made me watch some Home and Away. Damn you!
>>
>> Inconclusive results. iotop shows about 2MB/sec to two storage groups.
>> gnome-system-monitor shows mythbackend and mount.ntfs both ranging from 3
>> to 6% CPU. Both cpus running about 15-20%
>> some recordings OK. Some show corruption. Corrupt shows are on Sommet and
>> Prime. This is not always the case.
>
>
> Probably not a HD or RAM bottleneck if they're not all corrupt.
>
> Yes, and IO looks trivial.
>
>
> Maybe do some testing with commercial detection off in case that is
> corrupting them somehow.
>
> Can do. Surely it doesn't run for live tv though?
>
>
> Might also be worth looking into whether one tuner in particular is the
> source of corrupt recordings.
>
> Do you know if the tuner that was used stored in the DB anywhere? Might save
> me some time.
>
>
>
>>
>> Interesting backend log entry:
>> 11:55:39 zeus mythbackend: mythbackend[2503]: W DeviceReadBuffer
>> recorders/DeviceReadBuffer.cpp:555 (Poll)
>> DevRdB(/dev/dvb/adapter1/frontend1): Poll took an unusually long time 2547
>> ms
>>
>> Last 2000 lines of the backend log:
>> cat /var/log/mythtv/mythbackend.log | tail -2000 | pastebinit
>> http://paste.ubuntu.com/7757924/
>>
>> I'll investigate that log entry further.
>
> Makes me wonder if I should try different firmware. Cant remember where I
> got the current version from. Probably via the linux tv wiki. I recall there
> were multiple versions.
>
>
> Have a look at the kernel log too.
>
> Nothing shows up around the time I tested multiple recordings.
>
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Yeah - check the firmware. I had a *very* frustrating problem with
pixellated recordings & live TV which resulted in multiple trips up
the roof & to Jaycar trying to solve a reception problem, when in fact
I needed to reinstall the card's firmware (a Hauppage HVR-2210).

Of course your problem could still be reception-related.... :)