its 45 minutes

Use the same bit rate and you'll get the same quality. However, a 45-minute video file is going to be massive, no matter what you do.

I suggest you break the video up into "chapters" so as to reduce the strain on the bandwidth. If you don't have a very fast server, it'll take forever to download.

can you describe the chapters?
thank you

Chapters = logical breaks.

what fridge said,,
45 minutes is way over my internet attention span,, so as long its available for download, size isn't that important ,.
if i need to see it , just download and watch it later

I'd look into DIVX for something that long. I don't have a lot of experience with it but it seems to maintain quality at very low bitrates.

DIVX is MPEG4. Vegas (6 and 7) has Main Concept and Sony AVC (also MPEG4). Take one minute of footage to test various renders at different bitrates to see how low you can go to maintain your quality, and compare the file sizes. AVC will give you a similar quality to MPEG2 at much lower bitrates, thus smaller files.

You might throw wmv testing in with the above minute footage to compare and see which one you like the best.

The PBS series Frontline puts its episodes up on the web. They are generally an hour long and they break them up into about 6 files or "chapters." Go to PBS.org and see how they do it.

If anyone is intereseted enough in the material they will not have a problem clicking an extra file or 5.

the truth is that if it's worth it, folks will wait. Just look at all the torrents that people download across days and days. Content outweighs almost any hurdle if it's desired strongly enough (those are important words to remember).

Dave

If you use a streaming server, you can just encode a single file. I have done several long programs up to 90 minutes that I stream on a server that will allow you to watch for a while, then if you want to go back later, just drag the button to where you left off. It has to re-buffer whenever you skip forward, but that only takes about 5 seconds or so. I typically use windows media9 640x480 at 29.97 512 kbps. This provides quite nice results in my opinion.

JAB

Encoding a 45 minute video is no different than creating a 5 minute one. Yes the final file size can be on the big side, but all three formats you listed support HTTP progressive download streaming ( FLV, MOV, WMV ), so as long as you don't go crazy with the data-rate your broadband users will be able to watch the video while it is downloading. ( to be safe I wouldn't use a rate higher than 400 kbps, which most broadband users should be able to handle )

Going the real streaming route ( not HTTP progressive ) can be less of a hassle for your users ( they can randomly jump to any place in your video), but the hosting costs for streaming video service are a lot higher. You also have to encode using a CBR for video streaming, which creates larger files compared to a VBR encoded video file.