Understanding the pv_picovoice_process() function.

[GSkoumal]

Hello, I am currently working on an STM32F407G-DISC1 attempting to use picovoice. I am able to read in PDM data and convert it to PCM, but I am struggling to understand what needs to be sent into the pv_picovoice_process() function. I understand that it is a different buffer of int16_t based on the API documentation. Mainly I need to understand what conversion is being done in the below loops present in the demo, what do these do? Why are we not just passing in the PCM buffer?

[mrrostam]

As stated in the API documentation, "the number of samples per frame can be obtained by calling pv_picovoice_frame_length." In other words, to use the process function, we need to pass 512 samples in this instance. Therefore, a helper ping pong buffer is employed instead of directly passing the output of the PDMToPCM function. This buffer accumulates the PCM samples, ensuring that the requirement is met