[mythtv] Re:DVB Todo

[Martin Smith]

>>> - Fix silent EOVERFLOW in recorder
>> I have done this, it now gets logged at RECORD level. I didn't
>> know whether it should exit recording on repeated errors.
>> Any opinions?

> I don't think exiting is an option (i would preffer my recordings
> to have holes in them over beeing cut short), but a warning at a
> higher level than record would be good, because the record level
> dumps quite a lot of data, if i'm not mistaken. Did you see this
> get logged at any time, and would the continuity counter warning
> catch it? If so, the warning at record level is probably ok.

I just saw an overflow reported in a recording I did this afternoon so it is
happening.

>> The biggest thing I did yesterday is add a database table called
>> dvb_signal_quality. When enabled a thread in the DVB recorder
>> writes data to this table every N seconds.
>
> Would not this belong in the DVBChannel class, along with the
> signal monitor that is in there already?

I did consider this but some of the items logged come from counters in the
recorder. It seemed to made sense to put in there and query the frontend for
its stats.

>> This includes the frontend signal stats and the number of stream
>> errors, bad packets and overflows at the application level. Data
>> is retained for M days where N and M are configurable via a new
>> settings screen.

> I dunno what you plan on making this do beyond logging it? Is the
> intention to make a legend plot so that the user could easily see
> signal dips?

The idea is that you can go back and look at what happened during the recording.
If there were zero overflows and a high bit error rate then the problems are
probably with the signal. If there's a lot of overflows then it's maybe slow
hardware.

There's plenty of programs that can be used to analyse it. I used OpenOffice to
pull data from MySQL and draw me a graph of the bit error rate over the test
recording period.

A real time display of signal quality would probably be useful, the set top
boxes can do this. I haven't had time to think about that.

> I'm sure it's okay, but mail it to me or the list.

Ok. I'll try and package it up some time later today and email it to you.

Martin