A method and apparatus for encoding/decoding of n-bit video data

An apparatus and a method for encoding/decoding N-bit image data are provided to change a hardware specification minimally in AVS(Audio and Video coding Standard), encode the N-bit image data, and simultaneously improve coding efficiency. The first adder(112) generates differential data in which predictive data of inputted image data are subtracted from the inputted image data. A transform and quantization unit(113) transforms a domain of the generated differential data into a frequency domain. The transform and quantization unit(113) quantizes the transformed differential data in response to bit depth indicating the accuracy of the inputted image data.