Shallow Thoughts : tags : pulseaudio

Akkana's Musings on Open Source Computing and Technology, Science, and Nature.

Thu, 07 May 2020

PulseAudio from the Command Line

Controlling PulseAudio from the Command Line #tags linux,audio,pulseaudio,ubuntu,cmdline

Controlling PulseAudio via pavucontrol is all very nice, but it's time consuming and fiddly: you have to do a lot of clicking in a lot of tabs any time you want to change anything.

So I've been learning how to control PulseAudio from the command line, so I can make aliases to switch between speakers quickly, or set audio defaults at login time.

That was going to be a blog post, but I think this is going to be an evolving document for quite some time, so instead, I just made it a page on the Linux section of my website: Controlling PulseAudio from the Command Line.

I also wrote a Python script, pulsehelper.py, that uses some of these commands to provide clearer output and easier switching. It even uses color and bold fonts if you have the termcolor module installed. Like the document, this script is likely to be evolving for quite some time.

Happy listening and recording!

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[ 12:21 May 07, 2020    More linux | permalink to this entry | comments ]

Mon, 04 May 2020

PulseAudio via GUI: Pavucontrol

(Note: this is not an alphabet post. You may have noticed I'm a little stuck on I. I hope to get un-stuck soon; but first, here are a pair of articles on configuring audio on Linux.)

I'm a very late adopter for PulseAudio. In the past, on my minimal Debian machines, nearly any sound problem could be made better by apt-get remove pulseaudio. But pulse seems like it's working better since those days, and a lot of applications (like Firefox) require it, so it's time to learn how to use it. Especially in these days of COVID-19 and video conferencing, when I'll need to be using the microphone and speakers a lot more. (I'd never actually had a reason to use the microphone on my last laptop.)

Beginner tutorials always start with something like "Go into System Preferences and click on Audio", leaving out anyone who doesn't use the standard desktop. The standard GUI PulseAudio controller is pavucontrol. It has four tabs.

[Configuration tab in pavucontrol]

Read more ...

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[ 18:04 May 04, 2020    More linux | permalink to this entry | comments ]

Fri, 20 Jul 2018

Pulseaudio: the more things change, the more they stay the same

Such a classic Linux story.

For a video I'll be showing during tonight's planetarium presentation (Sextants, Stars, and Satellites: Celestial Navigation Through the Ages, for anyone in the Los Alamos area), I wanted to get HDMI audio working from my laptop, running Debian Stretch. I'd done that once before on this laptop (HDMI Presentation Setup Part I and Part II) so I had some instructions to follow; but while aplay -l showed the HDMI audio device, aplay -D plughw:0,3 didn't play anything and alsamixer and alsamixergui only showed two devices, not the long list of devices I was used to seeing.

Web searches related to Linux HDMI audio all pointed to pulseaudio, which I don't use, and I was having trouble finding anything for plain ALSA without pulse. In the old days, removing pulseaudio used to be the cure for practically every Linux audio problem. But I thought to myself, It's been a couple years since I actually tried pulse, and people have told me it's better now. And it would be a relief to have pulseaudio working so things like Firefox would Just Work. Maybe I should try installing it and see what happens.

So I ran an aptitude search pulseaudio to find the package name I'd need to install. Imagine my surprise when it turned out that it was already installed!

So I did some more web searching to find out how to talk to pulse and figure out how to enable HDMI, or un-mute it, or whatever it was I needed. But to no avail: everything I found was stuff like "In the Ubuntu audio panel, do this". The few pages I found that listed commands to run didn't help -- the commands all gave errors.

Running short on time, I reverted to the old days: aptitude purge pulseaudio. Rebooted to make sure the audio system was reset, ran alsamixergui and sure enough, there were all my normal devices, including the IEC958 device for HDMI, which was indeed muted. I unmuted it, tried the video again -- and music blasted from my TV's speakers.

I'm sure there are machines where pulseaudio works. There are even a few people who have audio setups complicated enough to need something like pulseaudio. But in 2018, just as in 2006, aptitude purge pulseaudio is the easiest solution to a Linux sound problem.

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[ 14:17 Jul 20, 2018    More linux | permalink to this entry | comments ]