[alsa-devel] Incorrect name of PCM

[Takashi Iwai]

On Sun, 22 Jul 2018 17:38:50 +0200,
Christopher Head wrote:
> 
> Hi folks,
> I have an Asus P8H77-I motherboard. On board is an Intel HDA connected
> to a Via VT1708S codec. There are a number of analogue ports. In
> addition to them, on the back panel are an HDMI port (from an
> integrated GPU) and a TOSLINK port. The motherboard manual isn’t totally
> clear on whether the HDMI port can also carry sound or only video, but
> Windows claims to be able to send sound there, so probably yes. I don’t
> use the integrated GPU, though.
> 
> Here’s the problem:
> $ aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: PCH [HDA Intel PCH], device 0: VT1708S Analog [VT1708S Analog]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 0: PCH [HDA Intel PCH], device 2: VT1708S Alt Analog [VT1708S Alt
> Analog] Subdevices: 0/1
>   Subdevice #0: subdevice #0
> card 0: PCH [HDA Intel PCH], device 3: VT1708S Digital [VT1708S Digital]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 1: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0

Please look at the card numbers here.  The HDMI output is provided
from a different HD-audio controller (of GPU), so it's assigned to a
different card.  If you pass only "hdmi" to applications, it
implicitly assumes the default card 0.

For playing via HDMI on your machine, you'd need to pass as "aplay -L"
shows, one of the following:

> hdmi:CARD=NVidia,DEV=0
>     HDA NVidia, HDMI 0
>     HDMI Audio Output
> hdmi:CARD=NVidia,DEV=1
>     HDA NVidia, HDMI 1
>     HDMI Audio Output
> hdmi:CARD=NVidia,DEV=2
>     HDA NVidia, HDMI 2
>     HDMI Audio Output
> hdmi:CARD=NVidia,DEV=3
>     HDA NVidia, HDMI 3
>     HDMI Audio Output

The device number depends on the HDMI port you plugged in.
The above can be in a shorter form like "hdmi:1,0", too.


Takashi