The UMS422toRGB8Dither object provides conversion of YUV422 images to RGB8Dither images. This object inherits or overrides all methods from the UMSVideoDecoder base video decoder class and does not add new methods.
A YUV422 image is composed of 32 bits per pair of pixels. The pixels are in order from left to right, top to bottom. For each pair of pixels in memory, the first 8 bits are Y1. The next 8 bits are U. The next 8 bits are Y2. The last 8 bits are V.
A RGB8Dither image is composed of 8 bits per pixel. The pixels are in order from left to right, top to bottom. In memory, each pixel is an index into a colormap that is an array of colors. Each color is represented by red, green, and blue values.
Because of the format of the YUV422 images, the width must be an even number. This object does not scale images.
The size of the colormap for the RGB8Dither output image can be set with the set_colormap_attributes method. The maximum size is 256 entries. The minimum size is 8 entries. The quality of the output image increases with the number of entries. The supported sizes are 256, 128, 64, 32, 16, and 8. Other values are accepted by the object, but internally it will round down to the nearest value and not use the extra entries.
For introductory information, see Video Codec Objects.