[linux-dvb] Writing DVB Software - couple questions

Robert Schlabbach robert_s at gmx.net
Wed Feb 23 14:11:16 CET 2005


From: "Hamish Moffatt" <hamish at cloud.net.au>
> Right, but there wasn't a standard for analog tuners. Last time I tried
> this (years ago), it seemed that every TV app had its own card database
> about how the tuner was connected to the Bt848 etc.

Yes, those applications (like DScaler) directly control the hardware from
user mode and only use a simple "direct I/O" driver to get access to the
hardware registers. A pitiful design, of course. But as long as the card
makers weren't fit to provide any properly working drivers, and Microsoft
hadn't bothered to make their driver model fully work, that was the only
option.

> WDM had the video capture aspects covered but not the tuning.
> Did this ever get fixed?

Yes, long ago. And Microsoft provides all the user mode components and
interfaces to control the tuning, including frequency tables. See e.g. the
IAMTVTuner COM interface. It is the core control interface for analog TV
and FM radio tuning.

Oh yeah, and for digital television, it is now the ITuner COM interface
through which DVB (and ATSC Terrestrial) cards with BDA minidrivers are
controlled.

Regards,
--
Robert Schlabbach
e-mail: robert_s at gmx.net
Berlin, Germany





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