I bet I can save you hours of waiting in the edit bay.

Pre-rendering.

Wha? Huh? Isn’t that an Oxymoron?

Hang with me here for a minute.

Q. What necessitates media needing to be rendered?
A. Well, the fact that I put 10 different effects on one clip, including this groovy flying toaster effect..

Q. OK, slow down, Orson. Do you know why you have to render those?
A. Well, because my computer is too slow.

That may not be the case. Codecs – what your media is encoded and decoded for playback with – are designed to use as little storage as possible when encoding a media clip. Often times, the trade off for a small storage footprint is a media file so compressed that your computer simply cannot play those effects in real time. Yes, that $10,000 computer may be able to play the raw clip, but it simply cannot decode the media – and put your flying toasters and star wipe on it, along with the other tracks of video and star wipes – without dropping frames. Hey, it’s not the computers fault. You’re trying to make it do something it was never intended to do. Thus, you need to render. And render. And wait.

So, why not give your computer a break?

Give the computer a file that it can more easily decode – and put effects on – in real time. Yes, you need more storage, but is a little bit more storage cost worth your wait time? Have you seen how cheap storage is now?

Some tapeless codecs, like XDCAM, etc. are what they call “Long GOP” (Group of Pictures). Unlike the concept of film, where each frame is a complete, full frame picture, Long GOP based codecs only track the change from frame 1 to frame 2. This makes the information in frame 2 much smaller in size than a full frame of information. By only having a full frame of information every, say 15 frames, you save a plethora of space. This means longer recording times on those flash memory cards, and happier consumers. Until they want to edit it. And put flying toasters on it.

Other video compression technologies, like RED, AVCHD, or AVC-Intra, may not utilize Long GOP structures, but instead they compress the file even more – which makes your computer work even harder – just to play the file. Many of these compressed codec’s utilize encoding schemes, which can employ several other techniques to save space. Two of the most popular are:

  1. The camera not shooting a full size frame of information, but shooting a smaller scale version, and letting the computer scale it up to full HD frame size while it plays back.
  2. Shrinking the color space to save storage space, but yielding a file that degrades further in post and making it poor for chroma keying and VFX work.

Here is a good example to put things into perspective: HDV.  HDV is very common for consumers who want inexpensive HD on a small tape. HDV file size is over 70 times SMALLER than a clean, pristine, uncompressed signal. Your computer has to work much, much harder to play that file back and add effects – in real time. The same reason your car has issues pulling an additional 14,000 lbs.

So, you’ve now been sworn off of editing Long GOP and other uber compressed formats. What do you do with that groovy (pseudo) HD camera you just picked up?

This is where pre-rendering (finally) comes in. Take that compressed “camera original” media and “flip it” to a more robust codec that is NOT Long GOP based, or compressed to the nth degree.   There are dozens of software and/or hardware solutions out there, from your basic Apple Compressor, to your running-of-the-gamut solutions from Telestream.  This encode then yields a file that your NLE will love you for, and I guarantee you that your time waiting for that progress bar will decrease sharply. For you Johnny 5 “MORE INPUT!” data hogs out there, many encoding solutions out there have the ability to pass along the metadata inherent in those camera original files and incorporate them into the new files.  This means that within your NLE, you can sort, sift and organize, relying on the metadata introduced by the camera during recording.

Codec’s like Avid’s DNxHD or Apple’s ProRes have quality (bitrate) levels which are considered “broadcast ready”. They are of a high enough quality that almost any network would accept, in addition, since these codec’s are optimized for their respective editing platforms, they can do more nifty things in real time.

And, we have an added bonus: These “edit friendly” codec’s, like DNxHD and ProRes, hold up better in post. What does this mean? This means that the 10 effects you do place on the clip will not degrade the clip as much as the 10 clips you placed on your camera original. This makes for better compositing, better color grading, and eventually – a better end product.

So, set those files up and let your computer chug overnight – flipping those files into something less stressful. And those flying toasters? Don’t.