A method and a decoding or coding device for calculating at least one of run and level representations of respective quantized transform coefficients representing pixel values in a block of a video picture inserted in a coefficient array is disclosed. The method and the decoding or coding device are adjusted to generate a bitmask of the quantized transform coefficients, respectively perform a look up of the 8 least significant bits and the 8 most significant bits of the bitmask in a look up table, patch the looked up lower part and upper part bytemap values and insert the bytes of the first bytemap array from index position 8 minus the number of non-zeros in the 8 least significant bits of the bitmask.