SOLVED making sense of aplay -l and arecord -l outputs

pradtf · 2022-05-17 16:47:36

on my system aplay -l gives:

List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC891 Analog [ALC891 Analog]
  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
card 1: NVidia [HDA NVidia], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 10: HDMI 4 [HDMI 4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 11: HDMI 5 [HDMI 5]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio]
  Subdevices: 0/1
  Subdevice #0: subdevice #0

so this means i have 3 'cards':
card0 which is the onboard soundcard (i think)
card1 which would be an nvidia giving hdmi
card2 which really isn't a card, but my usb headphones (with mic)

a card can have multiple devices attached, it seems from the 6 devices on card1.
1. what does that actually mean? how can i have one hdmi port and have multiple devices attached to it? and what is the 1/1 subdevice?

all these devices except for card2 have 1 subdevice. card2 seems to have 2 subdevices and 0/1 is showing.
2. presumably that is the headphones?

arecord -l gives:

card 0: PCH [HDA Intel PCH], device 0: ALC891 Analog [ALC891 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 2: ALC891 Alt Analog [ALC891 Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

3. so 1/1 on card2 is the usb microphone?

4. why does card0 show up twice with the same info?

5. is there a guide or explanation anywhere for this sort of thing (since manpages and archwikis don't seem to have it)?

Last edited by pradtf (2022-05-17 22:12:14)

seth · 2022-05-17 20:51:30

google …
https://raspberrypi.stackexchange.com/q … y-used-for

why does card0 show up twice with the same info?

Because it doesn't. There're two analog inputs on that device.

how can i have one hdmi port

port != jack
https://download.nvidia.com/XFree86/gpu … u_n_codecs

"Subdevices: 0/1" means it's (currently) unavailable, could be due to powersaving?
https://bbs.archlinux.org/viewtopic.php?id=255795
JACK seems to cause that as well.

Is this an xy-question? Do you actually want to deal w/ a different problem?

V1del · 2022-05-17 21:19:03

I explained similar questions to someone will see if I can dig out the link for further reading, but a short gist of your questions.

You usually have one device per HDMI port. So each potential port has one output device it can play/put HDMI audio out to.
That is the headphones, contrary to your assumption it has one subdevice like every one else, the 0/1 means that that subdevice is currently occupied and unavailable, i.e. you are currently actively playing something back on them, ALSA/the kernel can generally only allow a single output getting occupied by a single application
that is the microphone, the 1/1 means the device is currently available and ready to be used
It doesn't, those are two distinct devices that you could potentially record from simultaneously
The internet at large, but yes it can be somewhat confusing, it's also a bit problematic to try and give a general overview here as a lot of this can depend on details of your setup. Other than that read my posts here

FWIW I didn't find the exact post I wanted to find, but this one should help explain why the device occupation stuff matters: https://bbs.archlinux.org/viewtopic.php … 8#p1639728

pradtf · 2022-05-17 21:44:38

yes seth! i do have a different problem:

it is to get sound with jack (or pipewire-jack), instead of pulseaudio.

i was hoping that if i could make sense of the outputs coming from aplay and arecord, then i'd be able to figure it out.

thx for the links - i couldn't find anything on the first one, probably because i didn't phrase it properly.
your link leads to
Understanding ALSA device, subdevice and cards
http://delogics.blogspot.com/2014/11/un … e-and.html
this is just what i've been looking for!
didn't realize the concept (and purpose) of card-device-subdevice till now!

0/1 thx for explaining what that means. don't know if it is due to powersaving - i'm on a desktop, so i don't think so.
i'll examine that discussion more closely, but the concluding suggestion was to disable the power saving daemon - i don't have one running.

there being "two analog inputs on that device", i guess one is the output and the other for the mic.

the nvidia link (under port != jack) says:
"Not all boards expose all connectors as digital outputs"
so this nvidia card has the capability to attach multiple devices, but this motherboard offers only one port.
[edit: hmmm. this may not be correct after reading V1del's post - i think i was confusing "port" with a physical output.]

appreciate your making time for explanations and links!

(marking this solved and getting on to the original problem)

Last edited by pradtf (2022-05-17 21:56:45)

pradtf · 2022-05-17 22:11:38

@V1del
thx for these excellent responses to each of my questions!
i'm starting to understand this sound thing better - i had no idea about anything beyond pulseaudio just worked (through gnome).

as for your answer to #5, i am always delighted to see your responses (that link being no exception)!
you've always been most helpful!

i can see why it is difficult to have a generalize howto if things depend on one's setup and i do find the wikis usually very useful, but linux sound (especially when one has never had a reason to understand it), is awkward for me at present.

Arch Linux

#1 2022-05-17 16:47:36

SOLVED making sense of aplay -l and arecord -l outputs

#2 2022-05-17 20:51:30

Re: SOLVED making sense of aplay -l and arecord -l outputs

#3 2022-05-17 21:19:03

Re: SOLVED making sense of aplay -l and arecord -l outputs

#4 2022-05-17 21:44:38

Re: SOLVED making sense of aplay -l and arecord -l outputs

#5 2022-05-17 22:11:38

Re: SOLVED making sense of aplay -l and arecord -l outputs

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