From an earlier post:

I left out the framerate and audio sample rate; it should inherit these from the input stream.

We’ve done two shows with the new mobile settings. Oddly enough we’ve had trouble with the “Flash feed” (http-delivered, FLV-muxed stream of same h.264/aac) both times with video not showing at first. The first week I deduced that the problem was the 12fps framerate of the source feed making Flash unhappy, so I added “fps=15” back into the encoding to force 15fps.

For the next week I made the source feed 15fps, and again the flash video was blank (but with audio). Oddly enough removing the “fps=15” fixed it. ???