macromedia flash flashcom: Hello.

Here is described how to use different codecs for different clients (Sorenson
Spark for Flash Player 7- and On2 VP6 for Flash Player 8+).

http://livedocs.adobe.com/fms/2/docs/00000081.html

But as I can see, it is only suitable for recorded .flv files.

Is there any possibilities to customize stream delivery or live streams?
Can FMS2 transcode streams on the fly?

Thank you.

FMS can't transcode or do any sort of recompression. It's bits in, bits out.

If you publish through the Flashplayer, you will alwaus have sorenson spark
encoded video (the flashplayer only has the decoder half of the VP6 codec). If
you want to publish live VP6 video, look into the Adobe Flash Video Encoder, or
On2 Flix Live.