Hi there,
Your post was very helpful. I am converting a bunch of FLV files that I downloaded from ustream.tv to MOV files. They are terribly crappy videos and vacillate between 5 to 25 FPS. I found no info on how to convert them to friendly files for FCP, so I ran a bunch of tests. This is the final and friendliest settings to convert ustream.tv FLV to MOV files using MPEG Streamclip so you can edit them in FCP without rendering issues and major stalls:
Compression: H.264
Quality: 100%
Sound: Uncompressed, Stereo, 48 kHz
Frame size: 640 x 480
Frame rate: 29.97
Interlaced Scaling: Checked
Reinterface Chroma: Checked
Field Dominance: Lower Field First
(Leave all other boxes unchecked and leave the rotation, zoom, and crop settings alone)
You can reduce the saturation to 89.3 if your vids get too saturated as mine did.
This should give you nice (and not huge) .mov files that FCP will really love. Making them any bigger isn’t necessary. See ya.