A video encoder and a decoder analyze the spatial content video data in an H.264 stream using the discrete cosine transform (DCT). Although the DCT is computed as part of the H.264 encoding process, it is not computed as part of the decoding process. Thus, one would compute the DCT of the video data after it has been reconstructed by the video decoder for video post-processing or enhanced video encoding. A method for accelerating the computation of the DCT at the decoder side when transmitting intra-mode macroblocks uses information computed by the encoder and transmitted as part of the H.264 video stream.