Macroblock mode decision biasing for video compression systems

An apparatus, stored on a computer-readable medium, for coding video frames in a video compression system, the apparatus comprising instructions for causing a computer to:

• receive an input image corresponding to a video frame, wherein the input image comprises a sample, and wherein the sample is represented by a number of bits;
• provide a plurality of coding modes, including a first coding mode and a second coding mode;
• provide a plurality of bias values, including a first bias value and a second bias value, wherein the first bias value corresponds to the first coding mode and the second bias value corresponds to the second coding mode, and wherein the second bias value is different from the first bias value;
• scale each of the plurality of bias values as a function of the number of bits representing the sample of the input image;
• provide a first coding mode sum corresponding to the first coding mode, comprising adding the first bias value and a match measure;
• provide a second coding mode sum corresponding to the second coding mode, comprising adding the second bias value and the match measure;
• and
• select a preferred coding mode from the plurality of coding modes, comprising selecting a minimum of a plurality of coding mode sums, wherein the plurality of coding mode sums includes the first coding mode sum and the second coding mode sum.

A system for coding video frames in a video compression system comprising:

• means for receiving an input image corresponding to a video frame, wherein the input image comprises a sample, and wherein the sample is represented by a number of bits;
• means for providing a plurality of coding modes, including a first coding mode and a second coding mode;
• means for providing a plurality of bias values, including a first bias value and a second bias value, wherein the first bias value corresponds to the first coding mode and the second bias value corresponds to the second coding mode, and wherein the second bias value is different from the first bias value;
• means for scaling each of the plurality of bias values as a function of the number of bits representing the sample of the input image;
• means for providing a first coding mode sum corresponding to the first coding mode, comprising means for adding the first bias value and a match measure;
• means for providing a second coding mode sum corresponding to the second coding mode, comprising means for adding the second bias value and the match measure;
• and
• means for selecting a preferred coding mode from the plurality of coding modes, comprising means for selecting a minimum of a plurality of coding mode sums, wherein the plurality of coding mode sums includes the first coding mode sum and the second coding mode sum.

A system comprising:

• means for selecting a coding precision as represented by a number of bits;
• means for checking whether a coding mode bias is to be used;
• means for selecting a bias amount for a coding mode decision for a macroblock, if the coding mode bias is to be used;
• means for automatically scaling the bias amount to match the coding precision, if the coding mode bias is to be used;
• and
• means for applying the scaled bias amount when selecting a coding mode for encoding the macroblock, if the coding mode bias is to be used;
• means for encoding the macroblock with a first one of a plurality of candidate coding modes to determine a number of bits created by the first candidate coding mode, if the coding mode bias is not to be used;
• means for decoding the macroblock to determine a decompressed result from the first candidate coding mode, if the coding mode bias is not to be used;
• means for making a quality measurement of the decompressed result, if the coding mode bias is not to be used;
• and
• means for selecting a best coding mode from the plurality of candidate coding modes, if the coding mode bias is not to be used.