[alsa-devel] Incorrect name of PCM

[Takashi Iwai]

On Mon, 23 Jul 2018 18:11:38 +0200,
Christopher Head wrote:
> 
> On July 23, 2018 12:34:34 AM PDT, Takashi Iwai <tiwai at suse.de> wrote:
> >
> >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.
> 
> Hi,
> Thanks for responding. Did you miss this part of the aplay -L output?

No.

> hdmi:CARD=PCH,DEV=0
> HDA Intel PCH, VT1708S Digital
> HDMI Audio Output
> 
> This is the part I think is wrong, not the parts mentioning the NVidia HDMI outputs.

Just ignore this entry.  alsa-lib tries to parse the all possible
outputs that are provided from the kernel interface.  Due to
historical reasons, this digital output might be either SPDIF or HDMI,
and alsa-lib has no knowledge to distinguish easily, hence both spdif
and hdmi device names are provided equally for such a case.

Again, on your machine, the HDMI output is the card#1, not card#0.
The hdmi alsa-lib definition for card#0 is nothing but an alias of the
general digital I/O.


HTH,

Takashi