[linux-dvb] Re: Alternative v4 demux API

[Michael Hunold <hunold@convergence.de>]

Hello Ralph,

>  > I like the idea of a source based routing in Michael's approach (we've 
>  > been discussing this issue before in another thread some months ago), 
>  > the idea not to specify input and output device of the demux but instead 
>  > specify a stream source in the decoder. This removes some ambingiuties.
>
> OK, I guess with the MPEG decoder using it this way is a little bit clearer.
> With both methods the application has to be aware that
> interdependencies with other PID filters exist.
Yes, with the future API applications must be more aware of special 
things anyway, for example that for some hardware not all PID filters 
are equal.

>  > If we want to remove even more ambinguities we should distinguish in the 
>  > demux API between general purpose filter banks and decoder-attached 
>  > filter banks.
>  > 
>  > Maybe this would even simplify using the API since the routing might get 
>  > more straightforward.
>
> True. Again this is the question wether to tell the application about all
> capabilities (wether it be through "CAP-ioctls" or the mere existence
> of devices) or to let the driver deal with it.
> In the latter case suddenly telling the driver to "decrypt a PID" can
> cause major headaches depending on the state of filter allocation ... 
In that case, the application should have told the driver upon filter 
allocation/opening that the filter might be used for decryption, too.

> And there are even more kinds of filter modes which cannot
> always be done by all filter banks. And there can be restrictions on
> which section filters can be used with which PID filters from which
> banks, etc. 
There should be a sane compromise here: applications should be aware of 
the most important restrictions and should be able to specify any 
special needs via flags. The rest is up to the driver IMHO.

> Ralph
CU
Michael.



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