[linux-dvb] Re: cinergyT2: which kernel/usb module to use?

[Holger Waechtler <holger@qanu.de>]

Klaus Schmidinger wrote:

> John Dalgliesh wrote:
>
> > On Mon, 29 Nov 2004, Klaus Schmidinger wrote:
> >
> > > From an application programmer's view it really would be great if 
> > > the driver
> > > gurus could agree on a reference implementation of how exactly tuning
> > > and waiting for a lock is supposed to be done...
> >
> >
> > I must be missing something here, but where is it useful to wait for 
> > lock
> > anyway - what's wrong with just waiting for some data to come 
> > through? I'm
> > not having much luck imagining an application where the demod's internal
> > idea of lock is any use waiting for, over just waiting for the actual
> > data that you want to get out to arrive.
>
> Well, that's what VDR originally did.
> But then there was this never ending series of problems with "unknown
> picture types" and "video data stream broken", and the general belief was
> that filters should only be set when a device has a stable lock.

Where do these messages come from? A properly designed MPEG decoder 
should be able to handle any input and recover sync if the incoming data 
contains garbled packets (despite the fact that all demods but the 
stv0299A mut the TS if it is not valid). All decoders but the av711x do 
so (you get the idea why I call it ancient and broken then and when? - ;)

I any case the frontend_notifier callback code in dvb_frontend.c should 
work around this av711x/stv0299A bug, doesn't it works anymore, did any 
of the recent changes introduced a bug in this code?

Holger