[mythtv-users] Fwd: Pixelation/Bad Recordings HDHR Prime -- I am at my wits end

Tue Aug 27 21:51:06 UTC 2013

On Tue, Aug 27, 2013 at 2:30 PM, Captain Hook <captainhookzero at gmail.com>wrote:

>
>
> On Tue, Aug 27, 2013 at 5:22 PM, Chris Porter <hoodlum7 at gmail.com> wrote:
>
>> On Tue, Aug 27, 2013 at 2:15 PM, Captain Hook <captainhookzero at gmail.com>wrote:
>>
>>> I am not sure how much bandwidth the packet loss test attempted to
>>> push.  This issue occurs when there is only a single recording happening,
>>> if that makes any difference.
>>>
>>> Here is a link to a diagram of my network.  Yes, my TrendNET 8 port
>>> gigabit switch is just an unmanaged switch.  I have a Sonicwall firewall
>>> and a separate Meraki access point (also both connected to the switch).  My
>>> frontend has another switch connected (also a TrendNET), but that is
>>> upstairs.  For what it's worth, my brand new frontend does act laggy at
>>> times with fast forward and loading the recordings screen but this is
>>> fairly rare.
>>>
>>> http://s21.postimg.org/iuqsauaif/Coax_Wiring_Home.jpg
>>>
>>> The splitter just prior to my HDHR Prime has alternated between Monster
>>> Cable splitter, Motorola 2 port signal booster, and a splitter I obtained
>>> from Comcast years ago.  All three exhibit this issue.
>>>
>>>
>>> On Tue, Aug 27, 2013 at 5:09 PM, Chris Porter <hoodlum7 at gmail.com>wrote:
>>>
>>>> On Tue, Aug 27, 2013 at 1:57 PM, Captain Hook <
>>>> captainhookzero at gmail.com> wrote:
>>>>
>>>>> Background
>>>>>  I have been having intermittent issues with recording quality with my
>>>>> HDHomeRun Prime with Comcast cablecard since the inception of this project.
>>>>> I am really remembering why I gave this HTPC nonsense up years ago, but I'm
>>>>> already significantly invested in this at this point and I am determined to
>>>>> see it through.
>>>>>
>>>>> Issues
>>>>>  Intermittent issues with recordings on MythTV. Some recordings will
>>>>> be perfect, others will have pixelation periodically, others will have
>>>>> heavy pixelation, yet others will be so bad that the recordings stop during
>>>>> playback. The same channel will not behave the same twice--sometimes things
>>>>> are fine, other times they are terrible. This seems to happen on any
>>>>> channel and do not occur at any particular time of the day or during any
>>>>> other operations or recordings on my network.
>>>>>
>>>>> During playback the pixelation occurs at exactly the same points on
>>>>> damaged recordings. This pixelation is also present in other frontends that
>>>>> I have used as well as playing them in VLC.
>>>>>
>>>>> Screenshot of pixelation:
>>>>> http://s18.postimg.org/uq2tslkzt/Capture_zpsfb6e2c2a.jpg
>>>>>
>>>>> Troubleshooting & Attempts at Resolution Thus Far
>>>>>  Ran packet loss tests--no packet loss
>>>>>  Signal showing 70-100% depending on channel--added Motorola 2 Port
>>>>> Signal Booster
>>>>>  Signal now showing 100% signal and 100% quality on channels that have
>>>>> shown pixelation--issue still occurs
>>>>>
>>>>> My Setup
>>>>>
>>>>> Backend Hardware
>>>>>  Intel i5 3570k
>>>>>  16GB RAM
>>>>>  Gigabyte GA-Z77-DS3H
>>>>>  Seagate 3TB x 3 (recordings volume)
>>>>>  Seagate 350GB (OS volume)
>>>>>
>>>>> Backend Software
>>>>>  VMware ESXi 5.1 (Free version)
>>>>>  Ubuntu 12.04 LTS
>>>>>  MythTV .26
>>>>>  4 vCPU cores
>>>>>  12 GB of vRAM
>>>>>
>>>>> Frontend Software
>>>>>  Ubuntu 12.04 LTS
>>>>>  MythTV .26
>>>>>  (Have both physical machines and VMs with this setup--pixelation
>>>>> occurs identically in the affected recordings as well as through VLC)
>>>>>
>>>>> Any ideas/suggestions would be greatly appreciated.
>>>>>
>>>>> _______________________________________________
>>>>> mythtv-users mailing list
>>>>> mythtv-users at mythtv.org
>>>>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>>>>>
>>>>>
>>>> do you have a splitter any where in the chain to the HDHR Prime?
>>>>
>>>> --
>>>> Working on World Domination since 2001
>>>>
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>>>>
>>>>
>>>
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>>>
>>>
>> If you have access to where your outside splitter is I would look at the
>> outputs to see what the dB drop is. It should be listed on the splitter. If
>> not you will have to look up the splitter model on line. Essentially you
>> would need to add up all the dB drops for all the splitters in the chain to
>> your HDHR prime. This chain is most likely the cause of poor quality.
>>
>> what I had to do for my house is get a distribution amplifier which
>> provided enough boost to overcome the all my splitters. I then placed this
>> amp outside in place of the cable company splitter. In your case, I would
>> have the distribution amp in place of "Comcast supplied splitter #1."  The
>> goal is to boost the supplied signal before it reaches any of the internal
>> house splitters.
>>
>> --
>> Working on World Domination since 2001
>>
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>>
>>
> I have not looked at the splitter on the outside of my house very closely,
> but I did look at the one inside the house (Comcast #2) and it shows
> -3.5db.  The Monster Cable one I *was* using showed around -7.5db (it is a
> 4 way splitter).  I would assume that the outside splitter probably loses
> 3.5db as well.
>
> I don't know how to see the dBmV and dB values for Signal Quality and
> Symbol Quality--I only see percentages.  Both show 100% on both Windows and
> Mythbuntu.  Signal strength is between 91-95% (without the Moto booster, it
> was at 100% with).
>
>
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>
>
Your HDHR Prime has a web interface. If you browse to the IP of your HDHR
you will see some status pages. tune a channel and browse through the
status page. ( I am at work now otherwise I would look at my HDHR to tell
you exactly where to go.)

However, lets go with the assumption the comcast splitter outside is -3.5db
as well. this means between #1 and #2 you have a -7db signal drop. This
does not take into count the splitter for the HDHR and your cable modem. We
also do not know what kind of signal as measured in dB or dBmV is comming
in to your #1 splitter.

the real goal here is to have an amp which negates all the dB drop from
your splitters in the house. My strong suggestion to you is to put your amp
in place of "Comcast supplied Splitter #1." This way the signal you are
getting from Comcast is amplified even more. This should be a good known
signal. By good signal I mean positive dB and dBmV values. This is the
strong signal from the head end. Since, your diagram shows a two way
splitter outside the home your 2 way amp should fit just perfectly.

-- 
Working on World Domination since 2001
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