[RFC] Hybrid cards was Re: [linux-dvb] Re: backwards compatability -was- actual cvs broken?

Manu Abraham abraham.manu at gmail.com
Thu Nov 3 12:36:18 CET 2005


Edgar Toernig wrote:

>Speaking about the BT878 based cards, the connection is already
>pretty loose.  The BT878 has two functional blocks - video capture
>and audio capture which show up as two different PCI devices.
>The bttv driver handles the video capture part and works fine
>without the dvb-driver.  The DVB "receiver" is connected to the
>audio part.  Unfortunately, the DVB receiver usually needs the I2C
>bus and some GPIO pins which are both part of the "video"-function
>of the BT878.  So the DVB driver has to contact the bttv driver
>whenever it wants access to these pins.
>  
>

There can be even more complicated issues. Imagine the bttv(878) is 
connected to an ASIC. This ASIC controls both Analog and Digital.
but the pronounced operations are all DVB. The analog operations are 
quite minimal. something like mute audio etc. Now it would look like the 
DVB parts is now handling the analog part too. For example how would 
this mute_audio be called, since there is no mute audio under DVB..

So where should this module belong ?

If someone comments on this, i would be interested in havinging a 
feedback on this. At present i have a few cards that have DVB-T + CVBS 
on the dst, as well ATSC + NTSC.


Manu




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