Declaring MOZZI_AUDIO_RATE at 48000 produces: not LSHIFT defined, RP2040

[poetaster]

I'm working on porting the Mutable Instruments libraries to arduino (partly based on Volker Boehms port to supercollider) and while trying a mozzi context declared a 48kHz audio rate which produces:

In file included from /home/mwa/Arduino/libraries/Mozzi/MozziGuts.h:31,
                 from /home/mwa/Arduino/libraries/Mozzi/Mozzi.h:33,
                 from /home/mwa/src/pipico/PlaitsI2S/PlaitsI2S.ino:45:
/home/mwa/Arduino/libraries/Mozzi/internal/config_checks_generic.h:182:2: error: #error Whoopsie, not LSHIFT defined for this audio rate. Please report and/or fix
  182 | #error Whoopsie, not LSHIFT defined for this audio rate. Please report and/or fix
      |  ^~~~~
Multiple libraries were found for "MozziConfigValues.h"
 Used: /home/mwa/Arduino/libraries/Mozzi
Multiple libraries were found for "FixMath.h"
 Used: /home/mwa/Arduino/libraries/FixMath
Multiple libraries were found for "I2S.h"
 Used: /home/mwa/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/I2S
Multiple libraries were found for "AudioBufferManager.h"
 Used: /home/mwa/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/AudioBufferManager
Multiple libraries were found for "SPI.h"
 Used: /home/mwa/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/SPI
Multiple libraries were found for "STMLIB.h"
 Used: /home/mwa/Arduino/libraries/STMLIB
Multiple libraries were found for "PLAITS.h"
 Used: /home/mwa/Arduino/libraries/PLAITS
Multiple libraries were found for "RPi_Pico_TimerInterrupt.h"
 Used: /home/mwa/Arduino/libraries/RPI_PICO_TimerInterrupt
Using library Mozzi at version 2.0.2 in folder: /home/mwa/Arduino/libraries/Mozzi 
Using library FixMath at version 1.0.9 in folder: /home/mwa/Arduino/libraries/FixMath 
Using library I2S at version 2.0 in folder: /home/mwa/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/I2S 
Using library AudioBufferManager at version 1.0.0 in folder: /home/mwa/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/AudioBufferManager 
Using library SPI at version 1.0 in folder: /home/mwa/.arduino15/packages/rp2040/hardware/rp2040/3.8.1/libraries/SPI 
Using library STMLIB at version 1.0.0 in folder: /home/mwa/Arduino/libraries/STMLIB 
Using library PLAITS at version 1.0.0 in folder: /home/mwa/Arduino/libraries/PLAITS 
Using library RPI_PICO_TimerInterrupt at version 1.3.1 in folder: /home/mwa/Arduino/libraries/RPI_PICO_TimerInterrupt 
exit status 1
Error compiling for board Raspberry Pi Pico.

[tomcombriat]

Yep, this is normal as 48000 is not a power of two: Mozzi uses the fact that the audio rate is a power of two to avoid some costly divisions. You have to fall back to 32768 or the (relatively untested) 65536 rate.

[poetaster]

Ah, ok. I think that means I can't run the MI code in Mozzi since all the internal tuning in, for instance, plaits is callibrated to a samplerate of 48000. Hmm. I could still try to run individual engines to see how they sound. very wip code: https://github.com/poetaster/arduinoMI based in large part on https://github.com/v7b1/mi-UGens

[poetaster]

I did some tests running a 98kHz PWM and that worked reasonably well (RP2350) so I'll try running some tests with 65536