In one example, an apparatus includes a video encoder configured to partition a block of video data into a first partition and a second partition using a geometric motion partition line, calculate a slope value and a y-intercept value of the geometric motion partition line, wherein the slope value and the y-intercept value comprise integer values, calculate a mask indicative of pixels of the block in the first partition and pixels of the block in the second partition, encode the first partition and the second partition based on the mask, and output the encoded first partition, the encoded second partition, the slope value, and the y-intercept value. This may allow for a fixed point implementation. A video decoder may receive the slope and y-intercept values to calculate the mask and decode the block based on the mask.