audio format
all formats but "best" are converted from the source format, there will be some quality loss. when "best" format is selected, the audio is kept in its original format whenever possible.
audio bitrate
bitrate is applied only when converting audio to a lossy format. cobalt can't improve the source audio quality, so choosing a bitrate over 128kbps may inflate the file size with no audible difference. perceived quality may vary by format.
youtube audio quality
cobalt will try to pick highest quality audio in audio mode. it may not be available depending on youtube's response, current traffic, and server status. custom instances may not support this option.
youtube audio track
preferred dub language
cobalt will use a dubbed audio track for selected language if it's available. if not, original will be used instead.
tiktok
cobalt will download the sound from the video without any changes by the post's author.