[alsa-devel] HDMI on HDA device=3

Mohammad Bahathir Hashim bahathir at gmail.com
Tue Nov 9 17:24:09 CET 2010

On 2010-11-09, David Henningsson <david.henningsson at canonical.com> wrote:
> I have seen a few HDMIs which share the HDA controller with the onboard 
> sound card, but the codecs are different, e g the onboard one is at 
> address #0 and the HDMI is at address #3 - or even #3, #7, #8 and #9 in 
> some cases.
> Now, if the user specifies the device string hdmi:x (where x is card 
> name/number), I'd like it to kind of autodetect this and use DEV=3 
> instead of DEV=0, and without breaking the cards where the hdmi is a 
> separate card with a codec at address #0. However, it still seems like 
> the device is at DEV=3 somehow.
> Now, looking at /usr/share/alsa/cards/HDA-Intel.conf, I notice that 
> there are entries HDA-Intel.pcm.hdmi.0 which sets DEV=3, so it seems 
> like someone already thought of this. However, just using "hdmi:x" does 
> not trigger "DEV=3". I'm still not grepping all of the alsa lisp 
> architecture stuff, so could someone explain to me how the 
> HDA-Intel.pcm.hdmi.0 entry relates to the "hdmi:x" alsa device string?

I am not sure about Intel HDMI, but, in my case with MacbookPro 6,2
(15" Mid 2010); the HDMI audio stream via NVIDIA HDMI can only be
started if I use hw:1,7 (or Mplayer's -ao alsa:device=hw=1.7). No
sound if I starts with 1,3. But, after started stream to 1,7; then, I
can use 1,3. 

So, in this, I always started with 1,7. Since I can change the HDMI
device ID on-demand with MPlayer, I have no issue with default ALSA
configuration. :)

Thank you.

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