Avidemux+cannot+use+that+file+as+audio+track

Or to CBR MP3:

Avidemux has a complex history with AAC audio due to licensing issues. While it can often play AAC audio inside a video file, it may struggle to import a standalone AAC/M4A file as an external track if the specific internal decoder isn't loaded. avidemux+cannot+use+that+file+as+audio+track