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Processing phase

After the preparation phase, the processing itself takes place. If running sequentially instead of parallel, the following is done for each frame pixel individually.

For each input track, the corresponding pixel is split into color components according to the actual color space of the project. All color components are converted to float (type of the C language) in the ranges [0.0..1.0] for R, G, B, A, Y or [- 0.5.. + 0.5] for U, V. If the project color space has no alpha channel, the alpha component is set to A=1.0.

If the function uses a different color space than the project uses, the required conversions are performed. The key color components (selected in the plugin GUI) are also converted to the function color space in the same manner.

For Blend Algebra, the values for output are preinitialized from the track which the output is to go to. All the other tracks are cleared if the corresponding checkbox in the plugin GUI is checked. For Blend Program, this step is not needed.