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

[Sean Greenslade]

On Mon, Feb 15, 2021 at 09:55:28AM -0800, Rich Shepard wrote:
> 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.

For the record, I would be very surprised if your version of pavucontrol
had anything to do with these issues. In your other email, you show this
output from your pacat record attempt:

> $ pacat -v -r --file-format=wav /tmp/sounds.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_output.pci-0000_0a_00.3.analog-stereo.monitor (index: 0, suspended: no).

Notice the last line, where it reports the source it has attached to is
the alsa output monitor source. This was recording the _output_ of your
built-in sound card, hence why you heard nothing upon playback.

Pacat / parec will respect the fallback selection as the default
recording source if you don't supply one explicitly, so that will most
likely be what made the difference between your tests.

--Sean