[linux-dvb] Re: why emergency exit on channel switching problems ?

[Jörg Wiedenfeld <wiedenfeld@moving-objects.de>]

Hi Klaus,
> > I recognize that vdr do an emergency exit after it takes
> > no data from the driver.
> > That is a good idea for the worse case, I think.
> > But when taking a record on a second card, the stop is annoying.
> > On my machine vdr has only problems after channel switching.
> > When I notice a black screen after channel switching,
> > I switch to another channel an back and the world is good.
> > Do you thing it is possible to integrate this workaround,
> > so vdr maybe don?t need to exit after doing a record with
> > no signal after channel switching.
>
> As far as I see this VDR only performs an emergency exit if the channel
> switching doesn't work *before* starting a recording.
Exact what I mean, and what I have seen.
I have connect a tv screen on the second card,
and the screen is black. So the first recorded file
has zero bytes, after a while the watchdog hits and
after a while the recording go on.

So the workaround for this time could be to switch
to another channel and back, when this problem is
present and then start to record the channel.
When this fails let the watchdog hit.

Is it possible to check the channel switching state ?
A timeout after reading the video device or so ?

>
> Since loading the driver newly when channel switching doesn't work
> always leads to a successful recording (at least that's what I have been
> observing in the past) I believe this is the way it should be.
my suggestion is only a add one
>
> The optimal solution would be if channel switching would finally work
> more reliably. Since it always works after reloading the driver I can't
> see where I could change something in VDR to improve this.
> Maybe the driver
> developers can point out what VDR is doing wrong in cDvbApi::SetChannel()?
ok, this is mutch more better.

> The strange thing is that channel switching works fine for a while, but then
> (especially in the EIT scanner, which switches every 20 seconds, but also
> sometimes when the user switches channels) suddenly becomes more and more
> failing, until almost every attemt to switch a channel fails. After a driver
> reload it works fine again. In the meantime I also can rule out a heat
> problem because I have installed an additional fan directly above the DVB cards,
> so they are now cooled extremely good. And the temperature also wouldn't change
> too much while reloading the driver, I guess.
I have also install a cooler, but there is no change in the channel
switching problem. There is no need to install a cooler.

Jörg



--
Info:
To unsubscribe send a mail to listar@linuxtv.org with "unsubscribe linux-dvb" as subject.