create the png data from post-deflated data

this function is designed to support animated gifs, although stb_image doesn't support it two back is the image from two frames ago, used for a very s

decode one 64-entry block--

get some unsigned bits

returns 1 if the product of two signed shorts is valid, 0 on overflow.

set up the kernels

read 16bit value and convert to 24bit RGB

downscale image with nearest-neighbor interpolation

* Get the size of screen where the SDL window runs in. * * SDL_Window* window could be NULL, which means we get the screen size of the default 0-ind

encode a prompt - points - boxes - masks TODO: currently just encode a single point for simplicity

ref: https://github.com/facebookresearch/segment-anything/blob/efeab7296ab579d4a261e554eca80faf6b33924a/segment_anything/modeling/sam.py#L164 resize l

build a table that decodes both magnitude and value of small ACs in one go.

decode image to YCbCr format

@OPTIMIZE: store non-zigzagged during the decode passes, and only de-zigzag when dequantizing

returns 1 if "a*b + add" has no negative terms/factors and doesn't overflow