Disabled effect in chain should bypass instead of silence

[Jan Ypma]

I'm using the Deere skin, and trying to set up some advanced effects. To this end, I'm putting 3 effects into one effect chain, e.g. Bitcrusher -> Echo -> Reverb.

I'm hitting seemlingly a bug in the audio processing under the following conditions:

 - There is more than 1 effect in the chain
 - The first effect is off, the second effect is on
 - The Dry/Mix knob is anywhere less than 100%, e.g. 95% to the right

Under these conditions, no dry signal hits the second effect AT ALL. Only an attenuated input signal is present, no effect is heard. Now, when the Dry/Wet is moved to 100%, the sound does hit the second effect (full-on, of course). Moving Dry/wet slightly to the left again kills all FX input signal. Any reverb or echo tail does ring out.

This bug is not present when effect 1 is also on; dry/wet then works as is expected (that is, as it would in a DAW).

So it seems that:

 - When Dry/Wet is at 100%, switching effect 1 off is a "bypass" of the effect, routing the input signal on to the next effect on the chain
 - When Dry/Wet is <100%, switching effect 1 off kills the complete remainder of the effect chain

Forum link: http://www.mixxx.org/forums/viewtopic.php?f=3&t=8477

[Jan Ypma (jypma)]

I think I found the problem, looks like an oversight in the initial effects code.

PR with a possible fix is here: https://github.com/mixxxdj/mixxx/pull/989

[Daniel Schürmann (daschuer)]

Great! I am glad you have found it.
Before merge, you need to become a Mixxx contrinutor.
Please sign:
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and comment here when done.
Thank you very much.

[Jan Ypma (jypma)]

I've just signed the contributor agreement.

[ronso0 (ronso0)]

I noticed this issue but suspected my script to be faulty..
Just compiled rev5905 it works as expected.
Thanks!

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/8621