Compression maybe with sidechain

Algorithm development and general DSP issues

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rasmus
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Joined: Mon Jan 13, 2014 8:43 am

Compression maybe with sidechain

Post by rasmus »

Is there any good compression codes out there? Maybe with an input for sidechain.

I know that there are some limiters among the Free DSP programs, but all the programs from Keith Barr doesn't have any description of what the three POTS controls.

How can I see from the code what the potentiometers will control?

Thank you
frank
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Post by frank »

It doesn't look like Keith used the POTs for any control, the limiters he put up were all fixed in function. I suggest you read the knowledge base about level detection and continue down that page into limiters, etc. He explains things there, see http://www.spinsemi.com/knowledge_base/ ... _detection
Frank Thomson
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Mcfly
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Post by Mcfly »

Regarding this limiter code, is there any way to make the threshold variable with a pot?

Code: Select all

equ sigin reg0	
equ avg reg1	 
rdax adcl,0.5	 
rdax adcr,0.5	 
wrax sigin,1	 
mulx sigin	 ;square
rdfx avg,0.001	 
wrax avg,1	;average
log 0.5,0	;[square
exp 1,0	;root]
log -1,-0.125	;[1/X, set thresh @2 bits (2/16ths)
exp 1,0	;]
mulx sigin	;gain reduce
sof 1.5,0	 ;restore level
wrax dacl,1	 
wrax dacr,0
Digital Larry
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Post by Digital Larry »

Regarding this limiter code, is there any way to make the threshold variable with a pot?
Off the top of my head, I would add a MULX POTx after the "average" line and before the "square" line. You might need to boost the level a bit before the MULX POTx there to give you room to bring it down.
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