1. An apparatus for decoding video compression coded data into which prediction error information indicating differences between a predicted image generated from a decoded image and an image being coded was quantized and coded, comprising: a standard predicted image generating unit which generates a standard decoded image of standard image quality based on said prediction error information and generates a standard predicted image of standard image quality based on said standard decoded image; a non-standard decoded image generating unit which generates a non-standard decoded image different in image quality from said standard decoded image based on said prediction error information; a non-standard predicted image generating unit which generates a non-standard predicted image different in image quality from said standard predicted image based on said non-standard decoded image; and a correction value calculating unit which calculates correction values corresponding to differences between said standard predicted image and said non-standard predicted image, wherein said non-standard decoded image generating unit comprises a predicted image reconstructing unit which corrects said non-standard predicted image based on said correction values, and a non-standard decoding unit which inverse-quantizes said prediction error information for reproduction and which adds the inverse-quantized prediction error information and said corrected non-standard predicted image to generate said non-standard decoded image.