A video decoding apparatus for decoding frequency coefficients within a square or rectangular frequency conversion unit having a size larger than or equal to 8x8, the frequency conversion unit being a unit of transformed residual signals of a spatial domain into the frequency coefficients of a frequency domain, the apparatus comprising: a) a decoder adapted to reconstruct, from encoded data, the frequency coefficients corresponding to the frequency conversion unit to thereby reconstruct a transformed and quantized frequency conversion block which has the size of the frequency conversion unit; and b) an inverse quantizer and inverse transformer adapted to inversely quantize and inversely transform the transformed and quantized frequency conversion block to reconstruct a residual block having residual signals that are differences between pixel values to be reconstructed and predicted pixel values thereof, c) wherein the decoder reconstructs the transformed and quantized frequency conversion block by the unit of frequency regions split from the frequency conversion unit in horizontal and vertical directions, all of the frequency regions having an equal size of 4x4, by c1) extracting, from the encoded data, frequency region encoding information indicating whether a frequency region corresponding thereto has at least one non-zero frequency coefficient, the extracted frequency region encoding information having a value of 0 or 1, c2) extracting from the encoded data and inversely scanning frequency coefficients corresponding to the frequency region when the extracted frequency region encoding information has a value of 1 and thereby indicates that the frequency region has at least one non-zero frequency coefficient, and c3) setting all frequency coefficients in the frequency region to 0, when the extracted frequency region encoding information has a value of 0 and thereby indicates that the frequency region does not have at least one non-zero frequency coefficient, c4) wherein the frequency region encoding information is extracted from the encoded data by the unit of frequency regions split from the frequency conversion unit. a) a decoder adapted to reconstruct, from encoded data, the frequency coefficients corresponding to the frequency conversion unit to thereby reconstruct a transformed and quantized frequency conversion block which has the size of the frequency conversion unit; and b) an inverse quantizer and inverse transformer adapted to inversely quantize and inversely transform the transformed and quantized frequency conversion block to reconstruct a residual block having residual signals that are differences between pixel values to be reconstructed and predicted pixel values thereof, c) wherein the decoder reconstructs the transformed and quantized frequency conversion block by the unit of frequency regions split from the frequency conversion unit in horizontal and vertical directions, all of the frequency regions having an equal size of 4x4, by c1) extracting, from the encoded data, frequency region encoding information indicating whether a frequency region corresponding thereto has at least one non-zero frequency coefficient, the extracted frequency region encoding information having a value of 0 or 1, c2) extracting from the encoded data and inversely scanning frequency coefficients corresponding to the frequency region when the extracted frequency region encoding information has a value of 1 and thereby indicates that the frequency region has at least one non-zero frequency coefficient, and c3) setting all frequency coefficients in the frequency region to 0, when the extracted frequency region encoding information has a value of 0 and thereby indicates that the frequency region does not have at least one non-zero frequency coefficient, c4) wherein the frequency region encoding information is extracted from the encoded data by the unit of frequency regions split from the frequency conversion unit. c1) extracting, from the encoded data, frequency region encoding information indicating whether a frequency region corresponding thereto has at least one non-zero frequency coefficient, the extracted frequency region encoding information having a value of 0 or 1, c2) extracting from the encoded data and inversely scanning frequency coefficients corresponding to the frequency region when the extracted frequency region encoding information has a value of 1 and thereby indicates that the frequency region has at least one non-zero frequency coefficient, and c3) setting all frequency coefficients in the frequency region to 0, when the extracted frequency region encoding information has a value of 0 and thereby indicates that the frequency region does not have at least one non-zero frequency coefficient, c4) wherein the frequency region encoding information is extracted from the encoded data by the unit of frequency regions split from the frequency conversion unit.