Hi,
I don’t know whether u can see this information. I finally find a mac video converter called Foxreal Video converter for Mac can solve this problem easily. This is the first software i encountered supports ProRes 422 decode.
U can import into your ProRes 422 videos and convert to FLV. I tried it, and found it has advanced audio and video sync technology.
U can try it. Hopefully it can help u.
Smith