Hi, 

I have a project that includes a library in Arduino ( Opus audio encoder ) on a teensy 4.1 project.

The library requires I set these build flags.
build_flags = 
    -D USB_DUAL_SERIAL
     -D OPUS_BUILD
     -D FIXED_POINT
     -D OVERRIDE_OPUS_ALLOC
     -D OVERRIDE_OPUS_FREE
     -D VAR_ARRAYS
     -D HAVE_CONFIG_H
     -D OVERRIDE_OPUS_ALLOC_SCRATCH
     -D DISABLE_FLOAT_API
     -D OPUS_ARM_INLINE_EDSP
     -D EMBEDDED_ARM
     -D OPUS_ARM_ASM
     -D opus_alloc(x)=NULL
     -D opus_free(x)=NULL

I read somewhere I should add them to boards.txt that comes with the Arduino compiler so I don't have much hope I can get this working.

Does anyway know how I can pass these encoder flags to the Arduino compiler or if its at all possible ? Is this something I should ask on the Arduino forums or is it a Visual Micro question ? 

I am sort of stuck between a rock and a hard place since I need a debugger to complete my project ( platform IO ) doesn't have one.. and  VM ( visual micro ) where I don't know how to set these library specific build flags.

Am I right in thinking platform IO uses GCC and Visual Micro compiles using the Arduino IDE ? 

hi , switched on verbose build properties and attached a txt file.

I put these in the project properties page of visual micro in "Configuration Defines" entry

ED_ARM;OPUS_ARM_ASM;opus_alloc(x)=NULL;opus_free(x)=NULL 

I don't see them come up in the build flags in the build properties. do I need to keep the -D switch in each entry ? do I have this wrong ? 

does the -D switch just means define and I can just add these as #define xyz in a main.h header of the project as another way of doing the same thing ?
 
Thanks for you help with this.

Great thanks for the update. 

ps: You have the debug configuration enabled and you set config specific defines. When you switch to release they wont be applied. I suggest using the Global defines set in the same location.