Contents

kCVPixelFormatBlockWidth

Declaration

let kCVPixelFormatBlockWidth: CFString

Discussion

The width, in pixels, of the smallest byte-addressable group of pixels (type CFNumber). Used to assist with allocating memory for pixel formats that don’t have an integer value for bytes per pixel. Assumed to be 1 if this key is not present. Here are some examples of block widths for standard pixel formats:

  • 8-bit luminance only, block width is 1, the bits per block value is 8.

  • 16-bit 1555 RGB, block width is 1, the bits per block value is 16.

  • 32-bit 8888 ARGB, block width is 1, the bits per block value is 32.

  • 2vuy (CbYCrY), block width is 2, the bits per block value is 32.

  • 1-bit bitmap, block width is 8, the bits per block value is 8.

  • v210, block width is 6, the bits per block value is 128 .

See Also

Constants