[pulseaudio-discuss] No audio output; same setup worked before [RESOLVED]

[Rich Shepard]

On Sun, 14 Feb 2021, Rich Shepard wrote:

> Aha! I found the problem, at least with audacity. Audacity has a drop down
> combobox with output options. The default is, "HD-Audio Generic: ALC1220
> digital (HW:1,1)" and there's no speaker output. And, when I change the
> output to "HD-Audio Generic: ALC1220 digital (HW:1,0)" the same test
> recoding is heard from the speakers.

Sean, et al.:

Now I've resolved the issue with direct recording and playback using pacat.
Two things changed since when I logged out yesterday: 1) I had downgraded
pavucontrol from version 4.0 (which is in Slackware-current) to version 3.0
(which is the default in Slackware-14.2) and 2) I logged off the desktop and
logged back in this morning.

I created a recording:
$ pacat -v -r --file-format=wav direct-pacat-recording.wav
Opening a recording stream with sample specification 's16le 2ch 44100Hz' and channel map 'front-left,front-right'.
Connection established.
Stream successfully created.
Buffer metrics: maxlength=4194304, fragsize=352800
Using sample spec 's16le 2ch 44100Hz', channel map 'front-left,front-right'.
Connected to device alsa_input.usb-Focusrite_Scarlett_Solo_USB_Y7R5BX40493137-00.analog-stereo (index: 25, suspended: no).

and played it back to the external speakers:
$ pacat -v -p --file-format=wav direct-pacat-recording.wav
Opening a playback stream with sample specification 's16le 2ch 44100Hz' and channel map 'front-left,front-right'.
Connection established.
Stream successfully created.
Buffer metrics: maxlength=4194304, tlength=352800, prebuf=349276, minreq=3528
Using sample spec 's16le 2ch 44100Hz', channel map 'front-left,front-right'.
Connected to device alsa_output.pci-0000_0a_00.3.analog-stereo (index: 20, suspended: no).
Stream started.
Stream underrun.
Playback stream drained.y: 100160 usec. 
Draining connection to server.
(when I stopped it)

So there must be something (perhaps in pulseaudio or alsa) that's different
in the soon-to-be Slackware-15.0 that is not supported in Slackware-14.2.
But, since I first faced this problem with the default pavucontrol-3.0 I
honestly don't know why it stopped working then started again.

Stay well, all,

Rich