Pulldown removal with Compressor Quadrupling File sizes

W

WeeShooter

Member
I found this useful thread below describing an easy foolproof method for converting to true 24p using Compressor 3:

http://www.dvxuser.com/V6/showthread.php?t=98411

But alas, every clip that I convert becomes five times larger in size.

218.7 MB after compressor becomes 1.2 GB

71.8 MB becomes a new file of 391.2 MB

215 MB becomes 1.17 GB

Obviously there is more of a decompression going on here. Any Clues?
 
What's happening is you're transcoding from a highly compressed codec to a more uncompressed one, though ProRes is still very efficient compared to the Uncompressed or Animation codecs. Think of HDV as being like an MP3, and ProRes being more like a FLAC file.

You get two big advantages out of doing this: 1) native 23.98fps footage and 2) much faster rendering times (when compared to the same clip/filters on HDV). You pay for it in big space requirements, though - one tape of HDV converted into ProRes weighs in at about 45gb.

I should also add I've moved away from the Compressor workflow, because unfortunately I was still seeing some errors once in a while with interlace frames left in my 23.98 footage. It's something to do with how Compressor figures out the cadence from the HV20 footage, since it's not flagged like most 24p. It looks at the first few frames, but certain movement can throw it off in the rest of the clip.

If you want fool-proof conversion, look into JES Deinterlacer. You can transcode to ProRes with that as well, and it never makes errors. I've compared the results on the same input with Compressor and clips that gave Compressor problems went fine on JES. The downside to using JES is it doesn't handle batches as well, and you can't set up a quick droplet for conversion. But in my experience it does give the best results.
 
Yes, I had a sinking feeling about this, looks like I'm in the market for a larger hard drive, I wish there was a way to go back to stay in HDV in the conversion... I understand your mp3 explanation. This would be more the file size if I shot and recorded to disk with the HDMI output I suppose... I'm going to stick with Compressor at the moment but the errors you see once in a while with interlace frames left in your 23.98 footage; do these appear in a warning dialogue box in final cut, or is this something you're observing while watching your footage? I have JES but given the batch conversion capabilities of Compressor I'd rather save JES if I can easily see a problem file every now and then...

Thanks for your help!
 
Unfortunately you only spot the errors when you're looking through footage. There doesn't seem to be much rhyme or reason as to when they're going to occur, but they're definitely there. In fact, in one of the best-known HV20 + adapter clips, there's an error in one of the shots. The "Brevis on Ice" HV20 clip ( http://www.cinevate.com/images/brevisonice.wmv ) shows the Compressor workflow error at around 1:14-1:15 in the tree limb.
 
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