Mono sounds not working with enable-remixing = no - Is there an option to enable remixing for mono only?

[ghost_zero]

Hi,

as my soundsystem has its own upmix capabilities from stereo to 5.1, I would like to disable stereo remixing. HOWEVER, if I do so, mono soundtracks aren't played anymore. That is why I would like to only enable remixing for mono sounds.

Is this possible? If not, will it be possible in future versions?

[coling]

You could try creating a remap-sink with remix=no argument and remap only the front-left and front-right channels of your 5.1 sink. You could then play stereo sounds to this virtual sink and take advantage of the h/w upmix - if you play directly you get our software upmix.

Something like:

pactl load-module module-remap-sink sink_name=Stereo master="<insert sink name here>" channels=2 master_channel_map="front-left,front-right" channel_map="front-left,front-right" remix=no

I don't think there are any plans to allow fine grained control over the upmixing settings at present.

[ghost_zero]

Well. It would work BUT of course, if I playback a mono-track in between I would have to switch the sinks.

One question: How is the upmixing of Pulse done anyway. Is it just a simple reproduce of front and left channels to the rear speakers? If so, what about center and subwoofer?

[ghost_zero]

EDIT: I also thought already about the opposite way to create a sink that remaps the mono sound to the left and right speaker (both of them). However, I guess a combined one, isn't possible, is it?

[lennart]

Yes, we currently do not allow finegrained control on upmixing/downmixing, it's right now an all or nothing game.

The up/downmixing is pretty simple right now: we simply copy front to rear, and if LFE synthesizing is enabled generate an LFE channel as the sum of L and R. No filtering, no delay is applied to any of the synthesized channels.

[lennart]

Duplicate of #716