[alsa-devel] [PATCH v3 0/5] ALSA: hda - hdmi: ATI/AMD multi-channel and HBR support

[James Le Cuirot]

On Tue, 13 May 2014 17:16:17 +0100
James Le Cuirot <chewi at aura-online.co.uk> wrote:

> On Tue, 13 May 2014 15:27:47 +0300
> Anssi Hannula <anssi.hannula at iki.fi> wrote:
> 
> > Unfortunately I've been told that HD 4xxx cards and older do not
> > support multichannel playback, which I didn't know at the time (and
> > I had forgotten your case, hence I didn't get back to you - sorry
> > about that).
> 
> Thank you for the quick reply. I'm not sure whether that's strictly
> true. Wikipedia (though not always correct, I grant you) states that:
> 
> "The RV770 series GPU also supports xvYCC color space output and 7.1
> surround sound output (LPCM, AC3, DTS) over HDMI."
> 
> http://en.wikipedia.org/wiki/Radeon_HD_4000_Series#Multimedia_features
> 
> The HD 4670 has the RV730XT chip. It isn't clear in the above
> statement whether it is referring to the higher models in the range
> or the range as a whole, given that the RV770 is the foundation chip.
> Based on my experiences and what you have heard, it's probably the
> former. This news piece at AnandTech also seems to back it up.
> 
> "All of AMD's Radeon HD graphics cards have shipped with their own
> audio codec, but the Radeon HD 4800 series of cards finally adds
> support for 8-channel LPCM output over HDMI."
> 
> http://www.anandtech.com/show/2556
> 
> Looks like a new card for me then. Thanks for your help.

Aaaand after all that, I dig out the box for the old card to get ready
to sell it and what do I see printed on the front? 7.1 Channel Sound!
The box looks almost identical to this one:

http://www.overclockers.ua/video/ati-radeon-hd4670-ddr4/01-ati-radeon-hd4670-sapphire.jpg

This is very confusing. Any thoughts?

Regards,
James