[patch] XVideo on my Radeon

[Roland Scheidegger]

Benjamin Herrenschmidt wrote:
>> IIRC, note that these cards don't even have two dacs (and there is no 
>> notion of that in the driver code, only tvdac and primary dac), hence 
>> the DVI-D connector. 
> 
> Hrm... all cards have 2 DACs unless they are really old r100/rv100
> afaik ...
> 
>> This is a special "feature" of the r200 chip, it 
>> can drive two displays but only has one internal dac. Some cards with 
>> that chip though feature an external dac, like the original ati cards 
>> (though I believe there were also cards available with a dvi-i connector 
>> but not carrying analog signals...), but especially 8500le and 9100 
>> cards not always do. This may explain the weird looking table. I think 
>> for tv-out those cards always used the rage theatre chip, thus they 
>> could still use twin-view with crt + tv out.
> 
> Hrm... are you sure ? I though they all had a TV DAC (secondary DAC)
> (and additionally all rv chips and post r200 chips have an internal ERT
> TV encoder too).
Almost sure. Actually I think rv100 has a more advanced display engine 
than r200, integrating the 2nd dac (only the r100 is even simpler, with 
only one port). Not sure why high-end cards of that time skimped on 
features in that area - it's the same with nvidia, GF3 had a really 
primitive display engine, not even half as capable as that of the GF2MX.
You can for instance see the missing dac in this (obviously, old) value 
card roundup, look at the sapphire 8500le card:
http://www.xbitlabs.com/articles/video/print/6-value-roundup.html 
(though the text is a bit wrong "HydroVision" :-)).

Roland