---
title: kCVPixelFormatBlockWidth
framework: corevideo
role: symbol
role_heading: Global Variable
path: corevideo/kcvpixelformatblockwidth
---

# kCVPixelFormatBlockWidth

## Declaration

```swift
let kCVPixelFormatBlockWidth: CFString
```

## Discussion

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

- [kCVPixelFormatComponentRange](corevideo/kcvpixelformatcomponentrange.md)
- [kCVPixelFormatComponentRange_FullRange](corevideo/kcvpixelformatcomponentrange_fullrange.md)
- [kCVPixelFormatComponentRange_VideoRange](corevideo/kcvpixelformatcomponentrange_videorange.md)
- [kCVPixelFormatComponentRange_WideRange](corevideo/kcvpixelformatcomponentrange_widerange.md)
- [kCVPixelFormatContainsRGB](corevideo/kcvpixelformatcontainsrgb.md)
- [kCVPixelFormatContainsYCbCr](corevideo/kcvpixelformatcontainsycbcr.md)
- [kCVPixelFormatName](corevideo/kcvpixelformatname.md)
- [kCVPixelFormatConstant](corevideo/kcvpixelformatconstant.md)
- [kCVPixelFormatCodecType](corevideo/kcvpixelformatcodectype.md)
- [kCVPixelFormatFourCC](corevideo/kcvpixelformatfourcc.md)
- [kCVPixelFormatContainsAlpha](corevideo/kcvpixelformatcontainsalpha.md)
- [kCVPixelFormatPlanes](corevideo/kcvpixelformatplanes.md)
- [kCVPixelFormatBlockHeight](corevideo/kcvpixelformatblockheight.md)
- [kCVPixelFormatBitsPerBlock](corevideo/kcvpixelformatbitsperblock.md)
- [kCVPixelFormatBlockHorizontalAlignment](corevideo/kcvpixelformatblockhorizontalalignment.md)