As Audio Track | Avidemux Cannot Use That File

By switching the container to MKV, you often bypass the strict header requirements of the MP4 container, allowing Avidemux to accept the audio file.

Instead of adding an external track, use (GUI or command line) to merge your video + the external audio into a single MKV. Then open that MKV in Avidemux. Avidemux handles MKV’s internal audio tracks much better than external references. avidemux cannot use that file as audio track

: Convert them to WAV or MP3 . If you must use AAC, ensure it is exported as a raw ADTS stream rather than an .m4a container. By switching the container to MKV, you often