[mythtv-users] hdhomerun and 0.25 gives me artifacts on HDchannels

[Scott & Nicole Harris]

>>>I'm having trouble using my hdhomerun (HDHR3-EU) on mythtv 0.25. All the 
>>>SD channels are working fine but on HD channels I get artifacts on LiveTV 
>>>and recordings.
>>>I have a dedicated frontend/backend machine where I installed mythbuntu 
>>>12.04 Beta 2 (mythtv 0.25) + all updates for mythbuntu and mythtv.
>>>On another partition of the same machine I have my old installation of 
>>>mythbuntu 10.10 (mythtv 0.23-fixes) where everything works fine including 
>>>the HD channels, so I think its not an hardware failure.
>>>First I thought it was an VDPAU problem but the artifacts are also 
>>>appearing using a non VDPAU profile.
>>>Using hdhomerun_config_gui and vlc from 12.04 HD works fine.
>>>As I'm aware that mythbuntu 12.04 is still in development I installed 
>>>mythtv 0.25 (atrpms) on my CentOS 6 fileserver and used my Desktop as a 
>>>fronted (Fedora 16 also atrpms). Same thing there, the >>>HD channels 
>>>have artifacts.

>>>A while back I already posted my problem on the mythbuntu forums, but as 
>>>it seems its not a mythbuntu only problem. (I'm not familiar with the 
>>>rules of the mailing list, is it ok to post the link to the >>>forum 
>>>here? I posted my logs there)

>>>I live in Germany and the setup is a satellite signal converted to cable. 
>>>As it works on 10.10 I think its not a problem.

>>>Everyone here has  hdhomerun working with 0.25? (in Germany?)
>>>Any ideas what I can try?

>>I just went from 0.23 to 0.24 and 10.10 to 11.04 and I started seeing 
>>similar behavior--more breakups in HD OTA signals.
>>Searching on the SiliconDust website I found:
>>Packet loss
>>On slower machines or machines under high load the maximum receive socket 
>>buffer size for the system should be increased to 1MB:

>>    sudo sysctl -w net.core.rmem_max=1048576

>>This seems to have helped my situation, however, I still think I am 
>>getting more breakups under 11.04 than 10.10.

>>The other thing the SiliconDust web site suggests is testing for packet 
>>loss:
>>Low level test for network packet loss - ATSC/QAM/DVB:

>>1) Run HDHomeRun Setup and go into the channel editor. Choose a physical 
>>channel number (for example CH102). This is the number before the - in the 
>>Tune column.

>>2) From a cmd prompt run:
>>"C:\Program Files\Silicondust\HDHomeRun\hdhomerun_config" FFFFFFFF set 
>>/tuner0/channel auto:<channel number>
>>"C:\Program Files\Silicondust\HDHomeRun\hdhomerun_config" FFFFFFFF save 
>>/tuner0 null

>>Replace "<channel number>" with the physical channel number from HDHomeRun 
>>Setup (e.g. 102).

>>If you have more than one HDHomeRun unit then replace "FFFFFFFF" with the 
>>device ID of the desired unit.

>>You should see a series of dots. "n" indicates network packet loss. "t" 
>>indicates a reception error. "s" is informational.

>>(I have not tried this test yet.) I also upgraded to the latest firmware, 
>>(hdhomerun_atsc_firmware_20120405.bin)

>>What is really frustrating to me is that my TV's built-in tuner gets at 
>>least 3 other stations which just break-up on my HDHR. (Although it was 
>>like that before as well.)

>>Bob

>Hi Bob,
>thanks for your reply.

>I increased net.core.rmem_max to 1048576 but I'm still getting the 
>artifacts.
>Also tested for packet lost but I get:
>-- Video statistics --
>49056 packets received, 0 overflow errors, 0 network errors, 0 transport 
>errors, 0 sequence errors
>So it seems noting is lost.

>I think it has to be a software thing as it works fine after rebooting to 
>10.10 and also works from 12.04 using vlc.

>Jakob

Just out of curiosity, are you seeing this issue with only one recording 
running, or when there's multiple recordings?