[MacDV] Two beginner questions

[David Hillman]

   I've been making small ( few minutes ) movies for on-line use from my
Camcorder for a couple years, but I have a couple questions that should be
easy, I think.

   The video I've done before is all 320x240 .wmv format, because I had a
PC, and could only use the USB connection on my Sony camera.  Now that I
have iMovie and Firewire, I'd like to switch to 640x480.  I took a 6
minute segment and encoded it as MPEG-4 with H.264 and it wound up 18 MB.
That's fine, but the quality wasn't quite what I hoped for.  I don't need
DVD-quality, but this, while watchable, wasn't really sufficient.  What I
can use to get better image quality without exploding the file size
beyond, say, 4 meg/minute at 640x480?

   Also, while capturing video from my Camcorder, iMovie was randomly
breaking the video into chunks.  IOW, my 6 minutes of video was in 9
"clips" varying in length from 20 to 90 seconds.  Now, this might just
have been my old, slightly beat-up camera acting strange, but can this be
stopped?  Is iMovie seeing a pause in data from the camera and starting a
new clip?

   Thanks.

--
 David Hillman