What is rendering?
Depending on your video card, your software and your computer’s hard rive and bus specifications, you may have to render the entire movie before watching it back. In other words, the database is unable to retrieve the scenes fast enough to play back in real time. Therefore, it retrieves them once by one and electronically compiles them together into a new, and longer, file that can be played back all at once. This is how the less expensive systems operate. Effects and transitions also have to be rendered and saved to the hard drive before playback for recording – that is unless you have one of the newer and more expensive “dual-stream” video editing solutions. To create a transition where two or more video streams are mixed together – like in a wipe, dissolve or special effect, the two streams must be uncompressed, electronically taken apart into their ones and zeros, temporarily stored in RAM, mixed back together, and then compressed again, creating a new digital file.
In the olden days, when I first wrote this FAQ, rendering was the curse of the non-linear editing system user. Well, it still is, but if you’re using the right system, you won’t come across it very often. Final Cut Pro, for example, added huge numbers of real time features starting in version 4. In version 5, they’ve built on this even more. Effects such as dissolves appear immediately without any kind of waiting time. However, if you’re doing composites with more than a few layers, you’ll still encounter rendering. And of course there are many systems other than Final Cut Pro that lack real time abilities. For these, rendering continues to be the NLE user’s curse.
