[mythtv-users] Scheduled recording failed at start didn't retry

Stephen Worthington stephen_agent at jsw.gen.nz
Tue Feb 19 16:15:53 UTC 2019

On Tue, 19 Feb 2019 09:02:51 -0500, you wrote:

>On 2/19/19 8:31 AM, Michael T. Dean wrote:
>> On 02/19/2019 08:07 AM, James Abernathy wrote:
>>> I'm on the latest V30 (2:30.0+fixes.201902171942.70a58c0~ubuntu18.04.1)
>>> I had a program scheduled for 7am and when I checked at ~ 7:30 I 
>>> expected it to be displayed in the list of recordings in Green 
>>> because it was in process of recording.  It was displayed in normal 
>>> text (white on black) and very small.  When I clicked on the program 
>>> it couldn't find the file.  So I deleted the entry and restarted the 
>>> recording. Seems okay now, but weird.
>>> I have the journalctl output liked below.
>>> http://paste.ubuntu.com/p/nnByh5D5HZ/
>>> Feb 19 07:00:03 mythbuntu mythbackend[2426]: mythbackend[2426]: E 
>>> TVRecEvent tv_rec.cpp:3989 (TuningSignalCheck) TVRec[1]: 
>>> TuningSignalCheck: Hit pre-fail timeout
>>> Feb 19 07:00:04 mythbuntu mythbackend[2426]: mythbackend[2426]: W 
>>> TVRecEvent tv_rec.cpp:4020 (TuningSignalCheck) TVRec[1]: 
>>> TuningSignalCheck: taking more than 3000 ms to get a lock. marking 
>>> this recording as 'Failing'.
>>> Feb 19 07:00:04 mythbuntu mythbackend[2426]: mythbackend[2426]: W 
>>> TVRecEvent tv_rec.cpp:4022 (TuningSignalCheck) TVRec[1]: See 'Tuning 
>>> timeout' in mythtv-setup for this input
>> Your tuner failed to tune the channel before the timeout.  You need to 
>> increase the tuning (and, probably, signal) timeouts for your tuner(s) 
>> in mythtv-setup.  The defaults tend to be rather aggressive and only 
>> tend to work in the best of circumstances, so most people should 
>> increase them.  Even though the channel tuned successfully at a later 
>> time, because it failed to tune at the appropriate time, your timeouts 
>> are too low--they're too low to succeed in all conditions you will 
>> encounter (i.e. because signal strength varies or whatever).
>> For recordings, having a huge timeout (i.e. instead of a default 
>> 3000/1000ms, having more like 10000/10000ms) makes no difference on 
>> performance since no one is waiting on the tuner. The main reason for 
>> the aggressive defaults is because there's a huge impact for initial 
>> scanning--having to wait 10-20s per channel to find out there's no 
>> channel there when doing a channel scan of 70+ channels is incredibly 
>> slow. On Live TV, there's no impact to a huge timeout if tuning should 
>> work (i.e. if the channel actually exists and is properly set up in 
>> the database).  The only time the huge timeout will slow things for 
>> Live TV is if there's a failure to tune--which will mean waiting the 
>> entire timeout to get a failure message and be able to do whatever 
>> you're going to do about it.  So, I highly recommend just setting them 
>> both to 10s (10000ms) once you've got your system set up.
>> And, FWIW, if MythTV is unable to tune the channel/start the 
>> recording, it will not try again.  If there was a problem when the 
>> recording was meant to start, we assume that it's a systemic problem 
>> and may or may not require user intervention, so we don't keep trying 
>> the same thing and expecting a different result.  In this case, the 
>> user intervention required is increasing the timeouts.
>> Mike
>Thanks, I'll play with the timeouts. I assume they are the the 
>mythtv-setup -> Capture Card settings.
>I don't think this issues was too low a signal because most of my tuners 
>show 100% on all local channels but one.  This problem occurred on one 
>of the 100% ones. For the last 5 days I've been on a new tuner card, the 
>Hauppauge WinTV Quad PCIe card. It has better reception than my last 
>I'm wondering if it's too much signal. The station I was set to record 
>on a 7am this morning is one we record on most. Since the new tuner I 
>have paid particular attention to any issue while playing back those 
>recordings.  The recordings with the new card have been flawless. On my 
>old HDHR tuner, I occasionally would see a slight pixelation problem, 
>but very minor.  So far no issues with the new tuner.  This was the first.
>Are there ways to run tuner channel scans without messing up the 
>database.  Is it as simple as scanning in mythtv-setup -> Input 
>Connections -> Scan and not saving the output????
>Jim A

There are two timeout settings.  I believe that the "Signal timeout"
setting covers the time taken to lock on to the correct frequency and
start receiving digital data from the multiplex.  The "Tuning timeout"
covers how stations transmit their packets, not the time a tuner
actually takes to lock on to the correct frequency.  Some stations do
bad things with their control packets, so it takes a long time for
MythTV to see all the packets it needs to start a recording.  Here in
New Zealand, most stations are able to be tuned in less than 3000 ms,
but one station (THREE) usually takes nearly 7000 ms and occasionally
more than that.  After the MythTV update that changed the timeouts to
actually be enforced, I had to change the "Tuning timeout" settings on
all my DVB-T2 tuners to 10000 ms to reliably get THREE to tune in and
start recording.  You may have one or more stations doing that sort of
stupid thing.  It may only happen at certain times of the day, or when
certain programmes (or advertisements) are being broadcast.

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