I just compressed two XDCAM EX sequences (about 35-40 min each) into H.264, using the "Quicktime H.264" setting in Compressor. I set a specific bitrate (1500) and Compressor estimated the size of one video at 427.07MB. The finished file is actually 574.5MB. The other video had a similar discrepancy.
Why would the Compressor estimated size be so different from the real size, when I chose a fixed bitrate?
The reason this matters is that I'm uploading to a client's own free Vimeo account, and I have to get the videos under 500MB to post. So I'll have to recompress these with even lower settings--but I want to make sure I'm only compressing as much as I have to.