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The Linux audio stack demystified

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Re: The Linux audio stack demystified

#11

Post by Joeboy »

ladzoppelin wrote: post #6

"Professional audio will typicall utilize 24-bit. Everything higher than that is usually bogus. Bogus where only audiophiles will hear a difference." Does he mean internal DAW bit rates like 64/32bit float are bogus, I am probably reading it wrong ?

I think he's kind of wrong. As you say, anything going through any kind of professional audio editing software is probably 32/64 bit float. AFAIK all audio plugin standards work on 32/64 bit floats.

Although I imagine at least historically that's more because 32 bit floats are a native data type.

Re: The Linux audio stack demystified

#12

Post by tialaramex »

swatcoder wrote: post #8
ladzoppelin wrote: post #6

"Professional audio will typicall utilize 24-bit. Everything higher than that is usually bogus. Bogus where only audiophiles will hear a difference." Does he mean internal DAW bit rates like 64/32bit float are bogus, I am probably reading it wrong ?

I read them as talking about listening , as represented in mentioning audiophiles. The extra depth/range available in DAW's are useful for effects processing, mixing, and mastering and are a little colored by trying to squeeze max-performance DSP on a general-purpose/commodity CPU. I just don't take them as talking about that here though.

And the bits are basically free. If we had very cheap 24-bit floats and nothing bigger, maybe we'd use those, but we've got cheap 32-bit floats, so those are fine.

The most important property of floating point is "infinite headroom". In integer space, sixteen times quieter means 4 fewer bits of audio, get the levels wrong badly enough and people can hear your mistake even if you fix it later - but in float space it barely makes any difference, so long as the levels are correct in the final consumed audio nobody cares.

Re: The Linux audio stack demystified

#13

Post by cogman10 »

anvuong wrote: post #5

Thanks for the nice writing. But do you have any insight on why is bluetooth audio so clunky on Linux? I'm using a pair of Sony XM4 and I have never had any problems on my 4 Windows machines. But on Ubuntu (both 22.04 and 24.04), I have had to jump through many hoops, from editing a bunch of config files, changing kernel flags, disable and enable a bunch of things I don't understand (mostly from reading Arch Wiki), j…

It's so clunky, IMO, because bluetooth is a dumbass protocol with things in the standard that should not be there (including which audio codecs are supported with which levels of bluetooth). Rather than just being a more simple network of wireless devices, it's a very complex protocol which makes everything more complicated.

Why you may struggled could be anything from the firmware blob for your bluetooth device, to the kernel driver installed, to bluez, to the sound server you are using. Any one of those things messing up will lead to a bad experience.

I've had a relatively good experience with kde-plasma's bluetooth management stuff. But I still have to do dumb things like manually selecting which audio codec to use when I go on a call.

How could bluetooth be better? It should be at least 2 standards. 1 defining the wireless data transfer and network capabilities, a second which defines how a computer negotiates with a device to send audio. It shouldn't be 2 standards merged together like it currently is. Wifi Direct is more what bluetooth should be.

Re: The Linux audio stack demystified

#16

Post by disinterred »

anvuong wrote: post #5

Thanks for the nice writing. But do you have any insight on why is bluetooth audio so clunky on Linux? I'm using a pair of Sony XM4 and I have never had any problems on my 4 Windows machines. But on Ubuntu (both 22.04 and 24.04), I have had to jump through many hoops, from editing a bunch of config files, changing kernel flags, disable and enable a bunch of things I don't understand (mostly from reading Arch Wiki), j…

I use arch linux and have never had an issue with pairing bluetooth with anything. In fact, imho, it works much smoother than Windows because I keybind bluetoothctl to connect to any bluetooth headphones, speakers, keyboard or whatever automatically using their bluetooth device IDs. To do this you must first pair them (I use the blueman-manager gui) and then get their bluetooth device ids and keybind the bluetoothctl command. All of this is easy to do by asking ChatGPT. Hope this helps.

Re: The Linux audio stack demystified

#17

Post by gnramires »

epx wrote: post #7

I miss the simplicity of OSS :\

I use Void Linux, and find it reasonably simple :) (the reason I like the distro essentially)

Nothing against complex things, if that's your thing though. (usually complex things are made to be 'easier'/more convenient to operate too, for some definition of easier)

Re: The Linux audio stack demystified

#18

Post by ssl-3 »

disinterred wrote: post #16
anvuong wrote: post #5

Thanks for the nice writing. But do you have any insight on why is bluetooth audio so clunky on Linux? I'm using a pair of Sony XM4 and I have never had any problems on my 4 Windows machines. But on Ubuntu (both 22.04 and 24.04), I have had to jump through many hoops, from editing a bunch of config files, changing kernel flags, disable and enable a bunch of things I don't understand (mostly from reading Arch Wiki), j…

I use arch linux and have never had an issue with pairing bluetooth with anything. In fact, imho, it works much smoother than Windows because I keybind bluetoothctl to connect to any bluetooth headphones, speakers, keyboard or whatever automatically using their bluetooth device IDs. To do this you must first pair them (I use the blueman-manager gui) and then get their bluetooth device ids and keybind the bluetoothctl…

I've never done much with Bluetooth under desktop Linux, but that sounds like a woeful pain in the ass compared to the usual steps for Android or Windows:

1. Pair headphones in a couple of clicks/taps; sound comes out.

Re: The Linux audio stack demystified

#19

Post by ssl-3 »

gnramires wrote: post #17
epx wrote: post #7

I miss the simplicity of OSS :\

I use Void Linux, and find it reasonably simple :) (the reason I like the distro essentially) Nothing against complex things, if that's your thing though. (usually complex things are made to be 'easier'/more convenient to operate too, for some definition of easier)

I think they meant OSS (Open Sound System), not OSS (Open Source Software). In the Linux space, OSS predates ALSA.

(Back in the OSS days, we tended to use the term "free software" or even "copyleft" more than we did "OSS" to describe software licensing.)

Re: The Linux audio stack demystified

#20

Post by jpeloquin »

anvuong wrote: post #5

Thanks for the nice writing. But do you have any insight on why is bluetooth audio so clunky on Linux? I'm using a pair of Sony XM4 and I have never had any problems on my 4 Windows machines. But on Ubuntu (both 22.04 and 24.04), I have had to jump through many hoops, from editing a bunch of config files, changing kernel flags, disable and enable a bunch of things I don't understand (mostly from reading Arch Wiki), j…

I also have XM4's and they worked fine on Arch after addressing two problems:

Do you dual boot? Different OS's on the same computer will generate different pairing keys even though they share the same MAC, and this will cause connection issues. Usually that's reported as having to re-pair every time you switch OS's though.

https://unix.stackexchange.com/questions/255509/bluetooth-pa...

I've also experienced audio skipping & popping using a dual WiFi/Bluetooth card that were eliminated by disabling WiFi. Apparently the Linux driver was faulty and allowed some interference; the card worked fine on Windows.

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