Patent ID: 8385424

Claim:
A method comprising: using a series of butterfly structure operations on fixed-point numbers to apply a transform to a vector of source coefficients in order to generate a vector of transformed coefficients, wherein transformed coefficients in the vector of transformed coefficients are approximations of values that would be produced by transforming the vector of source coefficients using an ideal inverse discrete cosine transform; causing a media presentation unit to output visible signals based on transformed coefficients in the vector of transformed coefficients, wherein differences between results generated by one of the butterfly structure operations and results that would be generated by an equivalent butterfly structure operation using unlimited precision arithmetic are centered around zero, generating, with the device, a matrix of scaled coefficients by scaling each coefficient in a matrix of input coefficients; generating, with the, device, a matrix of biased coefficients that includes the vector of source coefficients by adding one or more bias values to a DC coefficient of the matrix of scaled coefficients; using the series of butterfly structure operations on the fixed-point numbers to apply the transform to each row vector in the matrix of biased coefficients in order to generate a matrix of intermediate coefficients; using the series of butterfly structure operations on the fixed-point numbers to apply the transform to each column vector in the matrix of intermediate coefficients in order to generate a matrix of transformed coefficients; and generating, with the device, a matrix of pixel component values by right-shifting coefficients in the matrix of transformed coefficients by a first magnitude.