[mythtv] Failed DVB recording

[Ben de Luca]

On 07/04/2005, at 5:58 PM, Tom Hughes wrote:

> In message <e558cc3b4d.tom at loxley.compton.nu>
>         Tom Hughes <tom at compton.nu> wrote:
>
>> In message <1108064943.420bbaaf3b10f at www.digitalregime.com>
>>           Taylor Jacob <rtjacob at earthlink.net> wrote:
>>
>>> Quoting Tom Hughes <tom at compton.nu>:
>>>
>>>> I had a DVB recording fail last night. The relevant log extract is:
>>>
>>>> 2005-02-09 18:30:04.271 DVB#0 DVB signal 5300 | snr 5000 | ber 
>>>> 143af12 | unc
>>>> 7961d18
>>>> 2005-02-09 18:30:04.273 DVB#0 Status: LOCK.
>>>> 2005-02-09 18:30:04.273 DVB#0 Multiplex Locked
>>>> 2005-02-09 18:30:10.966 DVB#0 Timeout Getting PMT
>>>> 2005-02-09 18:30:11.096 DVB#0 ERROR - Tuning for channel #4 failed.
>>>> 2005-02-09 18:30:11.176 Changing from None to RecordingOnly
>>>> 2005-02-09 18:30:11.237 DVB#0 Recorder: Card opened successfully 
>>>> (using PS
>>>> mode).
>>>> 2005-02-09 18:30:12.265 DVB#0 WARNING - No data from card in 1 
>>>> second.
>>>> 2005-02-09 18:30:13.316 DVB#0 WARNING - No data from card in 1 
>>>> second.
>>>> 2005-02-09 18:30:14.318 DVB#0 WARNING - No data from card in 1 
>>>> second.
>>>>
>>>> Obviously it failed to tune the right channel due to a timeout
>>>> getting the PMT from the multiplex. I don't know what the cause
>>>> of that was, but what happened afterwards is that it continued
>>>> to pretend it was recording and spew out those "No data" messages
>>>> for the duration of the program.
>>>
>>> Can you tune to this multiplex with zap and look at the PMT deltas?  
>>> There is
>>> currently a 5 second PMT timeout when attempting to get the PIDs for 
>>> the
>>> desired channel.  The average PMT delta is .1 to .2 seconds, so I 
>>> suspect that
>>> there was some issue with the deilvery of it.
>>
>> OK. I've worked out how to do this now by tuning with tzap and then
>> using dvbsnoop to look for the PMT data. They are coming in about
>> every 0.19 seconds most of the time - one or are longer but the 
>> longest
>> that I've seen is about 0.35 or so.
>
> I've had this happen a few more times recently so I decided to try
> increasing the timeout to see if it helped but I when I went to look
> at the code I found that the timeout is not actually 5 seconds but
> is just 0.3 seconds which would explain why I'm having problems as
> my gaps between PMTs are sometimes as long as 0.35 seconds.
>
> The code in DVBChannel::Tune does 3000 iterations of the loop and
> sleeps for 100us on each pass which gives 300000us or 0.3 seconds.
>
> I've just upped it to 30000 iterations to give a 3 second timeout
> and am rebuilding at the moment to see if that improves thing. It
> will probably take a few weeks before I'm really sure though as it
> doesn't fail very often.

> Tom
>
> -- 
> Tom Hughes (tom at compton.nu)
> http://www.compton.nu/
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>

I see this behavior almost daily with the same program, I had given up 
on ever watching doctor who again. So I can let you know how I go. I 
would find that the card that was doing this would not start recording 
again until the BE was restarted. I have been using the release the DVB 
card when not in use option lately which seems to work too.

bd