Explain Input Format Definition

[glebzlat]

I'm trying to add a custom board (OLIMEX ESP32-ADF rev.C) to my SIP VoIP project (not the OLIMEX SIP phone project, because it is raw and outdated) and I stumbled upon the following error:

Code: Select all

/home/gleb/esp/esp-adf/components/audio_stream/include/algorithm_stream.h:153:21: error: 'AUDIO_ADC_INPUT_CH_FORMAT' undeclared (first use in this function)

I searched for AUDIO_ADC_INPUT_CH_FORMAT in ESP-ADF source files and documentation and found the article explaining Audio Front-End Framework.

However, I do not understand how does it work. Because, e.g. LyraT v4.3 has two an ES8388 codec with two microphones, but its input format is "N", and ESP32-S3, which has two ADCs, has the format "RMNM". What is meant by channels here?