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Introduction

Rendering scenarios in Final Cut can change from moment to moment—shifting dynamically, for example, from high quality Real Time rendering to medium quality Real Time rendering, and then back again. This is the result of the core design of Final Cut—where image processing takes place on native video images exactly as they come out of the codec—and product evolution over time.

If you are creating an FxPlug effect running under Final Cut, you need to take these changing circumstances into account and structure your code accordingly so that your effect renders appropriately at all times.

This document describes Final Cut rendering scenarios where your FxPlug effect may need to adapt. It also specifies the relevant information from Final Cut that you can use to detect changing rendering circumstances.

This document does not recommend particular strategies an effect might use to respond to a particular rendering scenario, since each effect may handle a particular scenario differently. For example, if an effect is running on a low-res proxy image in medium quality Real Time rendering, the general idea would be for the effect to adjust itself by the render scale to produce an image similar to what it would produce in full-res high-quality. In practice, this might mean that a blur would scale its kernel size by the render scale, a geometric effect would distort itself for half-height single fields, and a color corrector would do nothing.

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