Originally Posted by VGeorgie

Yes but it's always a good idea to have a fallback to FLV if you can. Most Flash video players don't do this internally, so you either have to write a server script, or do it as a preloader or some other fancy footwork. Of the bigger players, forums for JWPlayer and Flowplayer have posts about people cracking this nut.

You might want to create a log for your server that detects the version of Flash your users have. They need to have v9r115 or later to play H.264 videos. I'd say if more than 3-4% of your users have less than this version you'll either need to go with FLV or use a fallback. Otherwise that's a fairly large market to lose.

On dvdvideosoft: It's a GUI wrapper for FFmpeg, so it uses the Sorenson Spark codec. Gives you maybe a third less quality for the same file size as VP6. Spark was developed a decade ago and while great in its day has been superceded since Flash 8 came out.