Converting QuickTime movie to Flash to reduce file size

[Vaugust]

I have just downloaded the ffmpegx application to my Mac OSX 10.4.10 (Intel) in order to convert a QuickTime Movie which is 162.9MB to a Flash movie, which I was hoping would be a smaller file size so that I can upload it to my website and make it viewable easily to visitors. However, something doesn't seem to be working. I dropped the movie into the "FROM" box, entered FLV into the "TO" box and clicked ENCODE. It seemed to encode it instantly. But in the VIDEO window, the size was shown as 700 MB! I clicked SAVE AS and named it, saving it to my Movie folder. However, the file which was saved was blank and could not be played.
I repeated the process several times and each time got the same result.
What is going wrong? Or what should I be doing? I'm new to this.
All I want is to convert a large file into one that's manageable but still good quality when played on my website. The movie was a Keynote presentation, with a lot of text slides and transitions, turned into a QuickTime movie. There is no audio.

Can anyone help?

[guns1inger]

FLV isn't necessarily smaller. Size is determined by bitrate, not format. Some formats compress better than others, so a smaller version might look better in one format than in another format. Personally, while Flash makes it easy for things like YouTube, the quality is not very good at low bitrates. You may find that a properly configured quicktime MOV at the right bitrate will give you better quality at the size you want.

Which ever approach you take, the key to it all is bitrate. File size = running time x bitrate. If you know the running time and the target size you can derive a bitrate to get you there. You need to tell your encoder what bitrate it must use.

[Vaugust]

Many thanks, guns1inger, but I have absolutely no idea how to determine the bit rate. The little movie in question is at present a QuickTime movie 165.9 MB, duration 06' 41, dimensions 800 x 600.

The problem is, as I mentioned before, that it was originally a Keynote (similar to PowerPoint) presentation, consisting of about 50 slides, mainly text with images, with transitions between the slides to make them run smoothly. Keynote gives you the option to turn the whole thing into a QuickTime movie, retaining the timing of the slides and transitions. But what happens when I compress this file (for instance I tried saving it for Web Streaming) is that all the text is blurred and the slides are shaky. So I wanted to find a compression method that would retain the clarity and timing of the slides, but reduce the file size quite a lot. I thought that Flash could do that, but I see from your answer that it doesn't.

So how do solve this? And how do I work out bitrate? And how do I get this software to work? So far no results at all!

Thanks a lot.