Getting my head around ProRes

M

mremil

New member
Hi guys,

My first post here, and I know it's basic, but I've been searching/browsing for hours and still can't find an answer.

I got my 151E yesterday and I'm trying to figure out which ProRes codec to use.

I'm looking at the overview from Apple (http://www.apple.com/finalcutstudio/finalcutpro/apple-prores.html), but it seems to me like the data rates are enormous for most of them?

From what I read the bitrate for the camera is 21 Mpbs, so why use something that's 147? Is there something that I completely misunderstand here (and im guessing there is...)?

I'm glad to have found this place, so much info to digest.. :)

- Mremil
 
The big difference between a codec like AVCHD and Prores is how they are compressed. With AVCHD, frames are compressed individually as well as over time, there is a complete frame of information every 15 frames or so and everything else in between is calculated. This gives very low data rates with very high picture quality, but it's a lot of heavy lifting for a computer to transcode on the fly.

Prores is an i-frame codec, all the information for each frame is in each frame. So the file size is much higher.

Wikipedia has good definitions on AVCHD and Prores.

The benefit to Prores is that it's less work for the computer to transcode on the fly. Which means you'll have plenty of horsepower left for handling real time effects, multiple layers, audio, etc.

The downside is you need to transcode initially before you start editing. On my iMac at home it takes about 10 sec. to transcode a 20 sec. clip.

Drives are cheap these days, and Prores will happily playback off of Firewire 800 or even 400 drives. USB 2 drives will also work, but try and stick with firewire or sata. USB 2 drives are great for archiving though. I copy all my cards to a USB 2 drive first and then import that to FCP. That USB drive becomes my archive of all the source material. Make sure you copy the whole card file structure, ie: everything on the card, not just the mts files. I set up a folder called card 1 and copy all card 1 contents to that, then card 2 etc.

Hope this helps

John C
 
Hey christie,

That was indeed a great help. And it makes total sense.

Still, I'm not sure which ProRes codec to choose (now that there's a bunch to choose from). I was just wondering if there was of them that would make sense to use, when considering the AVCHD source material?

Again, thank you for taking your time to help me out.

- Emil
 
What version of FCS are you using? If you have FCS 3 ProRes LT should be fine for avchd source material.
 
Hey matt s,

I'm using the latest version and was leaning towards going with ProRes LT, so I guess that's what I'll do.

Thanks for helping out.

Emil
 
Hey tigerten02,

Thanks for posting that link. I was going to look into the proxy version of ProRes and it looks pretty cool. Right now I'm editing on an iMac, so I guess there's no reason to use proxy, but it really good to know.

So much to learn... really appreciate all the help.

Emil
 
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