Quicktime Compression for Web...

[Dustin Waits]

I have a few videos I would like to host on my web site. Most of the are around 3-5 mins long. Unfortunately my server keeps timing out if I try to upload anything over about 35megs. I am using After Effects to encode either quicktime mpeg4 or quicktime with the sorenson 3 codec. (Which one is better?) When I go to export, I choose quictime movie. I select the file name. Then a window pops up to I can either choose the video settings, audio settings, or a little setting on the bottom that I don't understand (I will get to this later).

So I choose the video settings tab. A window for video settings pops up. At the top is a drop down menu of all the codecs. Lets say I choose the Sorenson 3. Below the drop down menu there is a box with a meter in it named quality. It's defaulted at medium. Below that is another box named motion with three boxes. One says "frames per second" [blank box], the next one says "Keyframe every [blank box] frames", and the last one says "limit data rate to [blank box] Kbytes/sec."

Now my question is...What do I set all of these too for the best results at a small file size? Does it work the same way if I choose mpeg4 instead of sorenson 3?

Second question: I mentioned a little box on the bottom of the first window that pops up for my settings. It says "prepare for internet streaming" with a check box next to it, and a drop down menu below it. In the menu it has these three options...
1. fast start
2. fast start - compressed header
3. hinted streaming
What do these mean?

If you have read this far you are a true warrior. Thanks alot for any replies and sorry for the huge post filled with annoying questions.

[Rob Lohman]

Last question first. Prepare for internet streaming adds some
stuff to the QuickTime file in the beginning so that a downloading
party (like your browser) knows that it should start to play as
soon as possible instead of downloading it fully first. I'm not
sure what the difference in the options is. Fast start is probably
what I just told you (compressed header just saves space I think,
although little) and hinted streaming is probably more of a
guideline then an "order" so to speak. But I could be wrong on
this.

If your server keeps timing out I'm wondering how you are
uploading. If you are uploading through your browser then
this is quite common and not the best way to upload. The best
way is FTP and most hosting parties support this. If you don't
know if they do and how you should do it ask them. You'll need
an ftp client like the excellent SmartFTP.

With an FTP upload you should be able to resume uploading if
the server times out or something happens to the connection.
Simply start uploading the same file in the same directory and
SmartFTP (in this case, but most clients) ask whether it should
overwrite or resume (your FTP server must support resum though).

If you drop the framerate of your movies any motion will look
more choppy (stutters), whether this is an option depends on
what you find irritating to watch and whether you have a lot
of motion or not. 15 fps is used a lot when going to a lower
framerate. It might also be that you need to lower the data
rate as well then to get the movie down, otherwise it just might
compress each frames less when going with a lower framerate
to still get the same compression (ie, you will loose frames but
keep the same filesize and thus the quality of each individual
frame will increase).

I just mentioned data rate. Data rate is the overal size of the
movie per second. So let's say you have 5 minute long
movie and you want it to be 20 megabyte in size. 5 Minutes is
300 seconds. 20 Megabyte is around 20480 kilobytes. Dividing
20480 with 300 yields 68.26. Or you need around a 68 KB/s
data rate to get that size.

Experimentation in how certain options change how the output
looks and how large the file gets is a good thing to do. This will
give you a much better feel for it than anyone can explain to you.

[David Hurdon]

To add one comment to Rob's excellent reply, when you experiment it isn't necessary to encode an entire clip. Use ten or twenty second segments so you get both a quick result to examine and a file size per second that you can use to determine how big the whole thing would be.

David Hurdon

[Dustin Waits]

Thanks so much for replying. I'm gonna continue trying different settings of frame rate and data rate to see if I can get better results. I'm using Microsoft Front Page to create and upload my web site. I have no idea how it works or anything like that (don't know too much about this internet thing = ] ).

[Rob Lohman]

Good tip David! Forgot that one. Dustin: Frontpage is something
you basically don't want to use for uploading work (heck, most
people don't want to use it at all, but that's a different story).
I'd suggest you talk to your hosting party (or ISP if they are
hosting your site) to ask about FTP access. That should allow
you to upload files as large as you want (within the maximum
size you are allowed to use for the website, ofcourse).

Good luck!