[mythtv-users] Mythbackend recording glitches

[Stephen Worthington]

On Mon, 15 Oct 2018 17:58:14 -0700, you wrote:

>On Mon, Oct 15, 2018 at 12:41 PM Peter Bennett <pb.mythtv at gmail.com> wrote:
>
>>
>>
>> On 10/15/2018 01:13 PM, Jay Harbeston (ISeePeople) wrote:
>>
>>
>>
>> On Oct 15, 2018, at 11:50 AM, Allen Edwards <allen.p.edwards at gmail.com>
>> wrote:
>>
>> I changed the name of my thread because the video card update problems are
>> gone (thanks to the help from all of you) and I am only left with glitches
>> in the recordings. I have done a lot of experimentation to try and isolate
>> the problem but am at a loss as to what is going on.
>>
>> Here is an example of a bad glitch http://l-36.com/mythtv.jpg
>> Here is an example of a small one blown up to show it
>> http://l-36.com/mythtv4.jpg
>>
>>
>>
>> You can use the hdhomerun_config and hdhomerun_config_gui utilities to see
>> the status of the stream using the following example:
>>
>> You will want to use the gui to set the channel to be verified and then do
>> the following:
>>
>> hdhomerun_config FFFFFFFF save /tuner0 capture.ts
>>
>>  This will capture the video to the file capture.ts, and also echo information while recording.
>>
>> Quoting from the hdhomerun development pdf document:
>>
>> 					............n...............................n..........ts..........
>> -- Video statistics --
>> 23323 packets recieved, 2 network errors, 1 transport errors, 1 sequence errors
>>
>> Advanced: A filename of “null” indicates no file should be created,
>> allowing the use of the save command as a diagnostic tool.
>>
>> Advanced: “-” may be used as a filename to indicate standard output,
>> allowing the save command to be used as a pipe on supported platforms.
>>
>> eg:     hdhomerun_aptureconfig FFFFFFFF save /tuner0 - | vlc -
>>
>> The dev document can be downloaded from SiliconDust, and has much more
>> information that can be had using the utility.
>> Something you can also check using the hdhomerun_config_gui is the signal
>> strength and quality live.
>> I have found these tools very handy.
>>
>> I had the same problem with HD Homerun Prme, and the above test showed
>> dropped packets. It was my router that was dropping UDP packets. I changed
>> to a switch instead of the router between the HDHomerun Prime and the
>> backend and the problem was solved.
>>
>> Peter
>>
>
>Thanks for the suggestions.
>
>I have tried a few things.
>1) sudo sysctl -w net.core.rmem_max=1048576  increased some buffer sizes --
>no change
>2) Ran hdhomerun_config FFFFFFFF save /tuner0 - | vlc - --where FFFFFFFF
>was the address of one of the tuners.  By the way, the tuners show 100%
>signal strength and 80 - 100% signal quality.  I got a series of dots
>across the screen and no indication of a problem.
>3) I switched the number of backend jobs to 1 from 2.  It was 2 in the
>Mythbuntu 8 system so I think that should be OK.  We will watch the show
>tomorrow morning to verify but I did not see any artifacts in about 5
>minutes of watching.
>
>
>dad at NewMyth:~$ hdhomerun_config 10126134 save /tuner0 null
>......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
>...................................................^C
>-- Video statistics --
>15743 packets received, 0 overflow errors, 0 network errors, 0 transport
>errors, 0 sequence errors
>
>Note, I could not play anything using VLC either on the myth box or my
>computer.  The file was capture.ts but I was mainly interested in the
>statistics, which did not show a problem.
>
>Doesn't seem like it is a HDHomerun problem.
>
>My guess is it is a myth problem either because the software no longer
>supports such a slow computer, or some configuration changed between my
>install of Mythbuntu 8 and 16.
>
>Allen

What sort of partition(s) are you recording to?  Please post the fstab
line you are using for it, so we can see what options are being used.
If it is on the same drive as the system partition, please post the
fstab line for that too.