Smart rendering: faster exports in Video by Zaweba

Every time a video is re-encoded it loses a little and takes a while. Smart rendering avoids both for the parts of your timeline that do not need it. In Video by Zaweba, plain cuts of footage that already match the export are copied straight into the new file instead of being decoded and compressed again.

That makes long exports of lightly edited material far quicker and keeps those stretches exactly as the camera recorded them. Here is how it decides, and what you can do to give it more to work with.

What counts as a plain cut

Smart rendering applies to footage that is already in the export's codec, profile, frame size and frame rate. If you shot ProRes and you are exporting ProRes with the same settings, untouched sections can be carried across as they are. The same goes for H.264 and H.265, with one extra condition: the cuts have to fall on key frames.

That condition comes from how those codecs work. H.264 and H.265 store a full picture only now and then, and the frames in between are described as changes from it. A cut that lands between two key frames leaves a frame that cannot be shown without its missing reference, so that stretch has to be encoded afresh. ProRes stores every frame whole, which is why it is the easiest case.

Anything that changes the picture means a fresh encode for that section: a colour grade, an effect, a title over the top, a transition, a speed change, a resize. The app copies what it can and encodes the rest, so a mostly untouched interview with a few titles still gains a lot.

When it says no

A helpful detail is that the export window tells you why when smart rendering cannot be used. That turns a puzzle into a checklist. It might be that the export size differs from the footage, that the frame rate does not match, or that the codec profile is not the same. Read the reason, decide whether the difference matters to you, and either change the export settings to match the source or accept a normal render.

Sometimes the right answer is to accept it. If the delivery needs a different codec from the one you shot, there is nothing to copy, and that is fine. Smart rendering is a shortcut when the stars align, not a rule your project has to follow.

Setting a project up to benefit

The biggest gains come from planning a little at the start. Set the project to the same frame size and rate as your main camera. If the finished file can be in the same codec, choose that in the export. For ProRes material this often means most of the timeline copies across.

For H.264 or H.265 camera files, cutting on key frames is rarely something you do by hand, and you should not distort an edit to chase it. Think of the speed-up as a bonus on the cuts that happen to line up rather than a goal.

It also helps to keep heavy treatments where they are needed. A grade applied to one clip only re-encodes that clip; a grade spread over the whole timeline touches everything.

Why it matters for quality

Speed is the obvious benefit, but the quieter one is fidelity. A copied section is bit for bit the original footage, with no generation loss at all. For archive masters, legal recordings, or any job where you want the untouched material to stay untouched, that is a real advantage.

Smart rendering sits beside the rest of the export tools in Video by Zaweba: presets, the render queue and the wider export options all work as before. Turn your attention to it when you are exporting long, lightly edited material in the camera's own format. That is where it saves the most time.