Ffmpeg Compose Mask

Context: $ARGUMENTS

Advanced compositing and channel surgery. If you are keying green-screens, see ffmpeg-chromakey. If you are grading color, see ffmpeg-lut-grade. This skill is for pixel-exact compositing math, alpha plumbing, and plane-level operations.

Quick start

• Composite A and B through a mask (white→A, black→B): → Step 1, 2 (maskedmerge)
• Add an alpha channel from a separate mask video: → Step 2 (alphamerge)
• Pull mask out of an RGBA/yuva file: → Step 2 (alphaextract)
• Warp one video using another as a displacement map: → Step 2 (displace)
• Grab a single plane (Y, U, V, R, G, B, A): → Step 2 (extractplanes)
• Rebuild image from separated planes: → Step 2 (mergeplanes)
• Chromatic aberration / per-channel pixel shift: → Step 2 (rgbashift)
• Apply a Photoshop blend mode (screen, multiply, overlay...): → Step 2 (blend)
• Fill connected pixel region (Photoshop paint bucket): → Step 2 (floodfill)

When to use