The UMSRGB24to420 object provides conversion of PadRGB24 images to YUV420Plane images. This object inherits or overrides all methods from the UMSVideoDecoder base video decoder class and does not add new methods.
A YUV420Plane image is composed of three planes in memory. The pixels are in order from left to right, top to bottom. The first plane is the Y component, 8 bits per pixel. The second is the U component, 8 bits each. Each U corresponds to a 2x2 block of Y pixels. The third is the V component, 8 bits each. Each V corresponds to a 2x2 block of Y pixels.
A PadRGB24 image is composed of 32 bits per pixel. The pixels are in order from left to right, top to bottom. In memory each pixel is 8 bits of pad, 8 bits of red, 8 bits of green, and 8 bits of blue.
Because of the format of the YUV420Plane images the width and height must both be even numbers. This object does not do scaling of the image.
Note: For this object the in CompressedFrame comp_frame argument to the decompress_frame method is the input PadRGB24 image even though it is not compressed. The inout ImageFrame image_frame argument is the output YUV420Plane image.
For introductory information, see Video Codec Objects.