Hi everybody,
the compression data rate can be found clicking on the video file itself (CTRL key) and then under Item Properties – Format. There you’ll see a list of qualities for your file, one of which is “Data Rate”. If your file is an HD file with 300+MB data rate you normally won’t be able to play/preview it. I have a powerful computer and it stops. I normally first convert my file (MPEG Streamclip does the job very well and it’s free) to Apple Pro Res, at the same resolution, and the Data Rate goes down to 16 MB/sec. Hope this can help.
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Giuliana Dieni Video Editor Motion Graphics –
Amsterdam,The Netherlands