5.2.6.4.5 Overlay Blender Attributes

When two or more video layers are used, alpha blending is performed to define the final image displayed. Each window has its own blending attributes.

  • CRKEY bit—Enables the chroma keying and match logic
  • DSTKEY bit—When written to one, destination keying is enabled
  • SFACTC—Source factor for the color channel blending equation
  • SFACTA—Source factor for the Alpha channel blending equation
  • DFACTC—Destination factor for the color channel blending equation
  • DFACTA—Destination factor
  • A0 field—Defines the source window alpha value 0
  • A1 field—Defines the source window alpha value 1