We have read the wowza multibitrate streaming, we understand ther are two way of doing it:

A- configure the encoder to send multiple streams with différents bitrates
B- send one bitrate and use the transcoder addon in order to have multibitrate output.


I solution A:
Is it a valid solution?
Do we need to Stream with AAC audio format?

In solution B

Is it better?
Does it require more resources CPU, Memory, Disk I/Os?
Do the output Streams are more delayed?

Thans in advance