Video coding mode selection using estimated coding costs

An apparatus for processing digital video data, the apparatus comprising:

• a transform module that generates transform coefficients for residual data of a block of pixels and generates a matrix of the transform coefficients, wherein a number of rows of the matrix of transform coefficients is equal to a number of rows of pixels in the block and a number of columns of the matrix of transform coefficients is equal to a number of columns of pixels in the block;
• a bit estimate module implemented as a processor that identifies one or more of the transform coefficients that are unquantized and non zero and will remain non zero when quantized, compares the matrix of transform coefficients to a matrix of thresholds, wherein the matrix of thresholds has a dimension the same as that of the matrix of transform coefficients, and further wherein the comparison results in a matrix of ones and zeros, where the zeros represent locations in the matrix of transform coefficients that will become zero after quantization and the ones represent locations in the matrix of transform coefficients that will remain non zero after quantization, sums a number of ones in the matrix of ones and zeros to compute a number of the transform coefficients identified as remaining non zero when quantized, sums absolute values of at least one of the transform coefficients in the matrix of transform coefficients that correspond to the location of the ones in the matrix of ones and zeros, and estimates a number of bits associated with coding of the residual data based on at least the number of non zero transform coefficients and the sum of the at least one non zero transform coefficient;
• and
• a control module that estimates a coding cost for coding the block of pixels based on at least the estimated number of bits associated with coding the residual data.

An apparatus for processing digital video data, the apparatus comprising:

• means for identifying one or more transform coefficients for residual data of a block of pixels that are non zero and unquantized and will remain non zero when quantized;
• means for generating a matrix of the transform coefficients, wherein a number of rows of the matrix of transform coefficients is equal to a number of rows of pixels in the block and a number of columns of the matrix of transform coefficients is equal to a number of columns of pixels in the block, wherein the identifying means compares the matrix of transform coefficients to a matrix of thresholds, wherein the matrix of thresholds has a dimension the same as that of the matrix of transform coefficients, and further wherein the comparison results in a matrix of ones and zeros, where the zeros represent locations in the matrix of transform coefficients that will become zero after quantization and the ones represent locations in the matrix of transform coefficients that will remain non zero after quantization;
• means for estimating a number of bits associated with coding of the residual data by summing a number of ones in the matrix of ones and zeros to compute a number of the transform coefficients identified as remaining non zero when quantized, summing absolute values of at least one of the transform coefficients in the matrix of transform coefficients that correspond to the location of the ones in the matrix of ones and zeros, and estimating the number of bits associated with coding of the residual data based on at least the number of non zero transform coefficients and the sum of the at least one non zero transform coefficient;
• means for estimating a coding cost for coding the block of pixels based on at least the estimated number of bits associated with coding the residual data.

A computer-program product for processing digital video data comprising a computer readable non-transitory medium having instructions thereon, the instructions comprising:

• code for identifying one or more transform coefficients for residual data of a block of pixels that are unquantized and non zero and will remain non zero when quantized;
• code for generating a matrix of the transform coefficients, wherein a number of rows of the matrix of transform coefficients is equal to a number of rows of pixels in the block and a number of columns of the matrix of transform coefficients is equal to a number of columns of pixels in the block;
• code for comparing the matrix of transform coefficients to a matrix of thresholds, wherein the matrix of thresholds has a dimension the same as that of the matrix of transform coefficients, and further wherein the comparison results in a matrix of ones and zeros, where the zeros represent locations in the matrix of transform coefficients that will become zero after quantization and the ones represent locations in the matrix of transform coefficients that will remain non zero after quantization;
• and
• code for summing a number of ones in the matrix of ones and zeros to compute a number of the transform coefficients identified as remaining non zero when quantized;
• code for summing absolute values of at least one of the transform coefficients in the matrix of transform coefficients that correspond to the location of the ones in the matrix of ones and zeros;
• code for estimating a number of bits associated with coding of the residual data based on at least the number of non zero transform coefficients and the sum of the at least one non zero transform coefficients;
• and
• code for estimating a coding cost for coding the block of pixels based on at least the estimated number of bits associated with coding the residual data.