24 bit playback

Submitted by dulnikovsky on Fri, 2020-04-10 16:33

Forums:

MOC version: 
2.5.2

Hello, I'm using MOC on my old mini PC with Debian Wheezy and a RME Digi 96 PCI sound card. I have build the newest version of MOC myself on the PC. Everything works fine except one thing:

I have some 96kHz 24 bit FLAC files. The /proc/asound filesystem shows me that the ALSA driver switches to 96kHz for playback of these files but does not switch to 24 bit playback, which is supported by the soundcard. It still shows 16 bit. Is 24 bit playback supported at all? The playlist window does not display anything about bit depth of current file. This should be also considered.

tomaszg

Fri, 2020-04-10 17:53

There is an option which should be activated in .moc/config file:

Allow24bitOutput = yes

For compatibility reasons, MOC by default doesn't use 24-bit mode. Enabling it should fix your problem if your soundcard accepts 32-bit samples (that it how 24-bit audio is usually transmitted).

There are however some soundcards that do not accept 32-bit samples and need real 24-bit samples. MOC doesn't support it yet. I have however an experimental code in my personal repository with support for it: https://gitlab.com/tomaszg/mocp