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

[BobW]

On 4/22/2012 6:02 AM, jakommo wrote:
> 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
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