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

Tue Aug 27 21:56:06 UTC 2013

On Tue, Aug 27, 2013 at 5:51 PM, Chris Porter <hoodlum7 at gmail.com> wrote:

> 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.
>>>>>>
>>>>>> _______________________________________________
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>>>>>> mythtv-users at mythtv.org
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>>>>>>
>>>>>>
>>>>> 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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>
>
Yes, I see it now, thanks.
Signal Strength93% (-4.6 dBmV)Signal Quality100% (36.8 dB)Symbol Quality100%

This is with BBC America, a channel I am seeing issues with even after
installing the signal booster.
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