You can only choose an audio bit depth when you specify flac or pcm for the value of Audio:Codec.
flac
pcm
You can only choose an audio bit order when you specify pcm for the value of Audio:Codec.
You can only choose an audio profile when you specify AAC for the value of Audio:Codec.
You can only choose whether an audio sample is signed when you specify pcm for the value of Audio:Codec.