[linux-dvb] RE : RE : linux-dvb and Dektec [was: DVB API update]

Wolfgang Wegner wolfgang at leila.ping.de
Thu Oct 4 11:00:40 CEST 2007

On Thu, Oct 04, 2007 at 10:30:50AM +0200, Thierry Lelegard wrote:
> > I think there is at least one usage case where one might want to
> > have the DekTec card integrated into the linux-dvb driver framework,
> > which already has been mentioned: us the existing linux-dvb applications
> > with it!
> > Especially dvbsnoop is a very helpful tool for some cases.
> > I definitely want to start another "war" about which functionality should
> > be in the kernel and which not, but IMHO the usage is not as separate as you
> > claim.
> You mean "don't want" maybe ;-)

oops... of course!

> To address both requirements:
> - Keep kernel code as small as possible
> - Use "exotic" devices through linux-dvb (not only Dektec, why not also
>   VideoPropulsion or Optibase devices, and even recorded TS files on disk).
> you may need a generic dvb "loopback" driver as described in my previous post.
> In that case, the device-specific code is written in userland and feeds the
> loopback driver.

Hmm... I am not sure if this is possible for all scenarios. For the "budget"
cards with no TS manipulation I see no problem, but for other cards and
functionalities, the user-space approach also has disadvantages.
(E.g. in another project, we used a software PLL for synchronization of a
decoder to an input TS - for such a thing to work, the TS handling has to
be quite near to the hardware, and I doubt this would be possible in userland.)

But again, this just as an example of the advantages the current drivers
have, I think there is no need for such a change. (Unless someone wants
to start a completely new and incompatible dvb framework, which I think would
be the consequence.)

Best regards,

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