# Example: mp3s_to_mkv.sh ./dir_source ./dir_output 48k
# Depends: GNU Coreutils 8.32 (date), ffmpeg, ffprobe
# Ref/Attrib: [1] FFmpeg Formats Documentation https://ffmpeg.org/ffmpeg-formats.html#toc-Metadata-2
# Example: mp3s_to_mkv.sh ./dir_source ./dir_output 48k
# Depends: GNU Coreutils 8.32 (date), ffmpeg, ffprobe
# Ref/Attrib: [1] FFmpeg Formats Documentation https://ffmpeg.org/ffmpeg-formats.html#toc-Metadata-2