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

[James Le Cuirot]

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.

Regards,
James