Method of reducing computations in transform and scaling processes in a digital video encoder using a threshold-based approach

A method of reducing computations in transform and scaling processes in video encoding processes, comprising:

• a. storing one or more thresholds in two or more lookup tables, wherein the two or more lookup tables include a first table for P-macroblocks and a second table for l-macroblocks;
• b. comparing a selected threshold from the one or more thresholds with a transform coefficient before scaling, wherein the selected threshold is selected based on one or more quantization parameters and one or more locations of coefficients;
• and
• c. eliminating computations where the transform coefficient before scaling is less than the selected threshold.

A method of reducing computations in transform and scaling processes in video encoding processes, comprising:

• a. determining a threshold based on one or more quantization parameters and one or more locations, wherein determining utilizes two or more look up tables and the two or more lookup tables include a first table for P-macroblocks and a second table for l-macroblocks;
• b. computing a vertical transform;
• c. computing an absolute sum using the vertical transform;
• and
• d. eliminating computations where the absolute sum is less than the threshold.

An apparatus comprising:

• a. a program module for determining one or more thresholds based on one or more quantization parameters and one or more locations, computing a vertical transform, computing an absolute sum using the vertical transform and eliminating computations where the absolute sum is less than the selected threshold;
• b. a processor for executing the program module;
• and
• c. one or more databases for storing two or more lookup tables, wherein the two or more lookup tables include a first table for P-macroblocks and a second table for l-macroblocks.

A video encoder comprising:

• a. a decoder;
• b. a component for transforming, scaling and quantizing coupled to the decoder;
• c. an entropy coder coupled to the component for transforming, scaling and quantizing, wherein the entropy coder produces one or more compressed video bits;
• and
• d. two or more lookup tables wherein the two or more lookup tables include a first table for P-macroblocks and a second table for l-macroblocks,
• wherein the component for transforming, scaling and quantizing avoids computations where a transform coefficient before scaling is less than a computed threshold, wherein the computed threshold is selected based on one or more quantization parameters and one or more locations of coefficients.

A video capture and display device comprising:

• a. a receiving unit for receiving video data;
• b. a display unit coupled to the receiving unit for displaying video data;
• c. an encoder coupled to the receiving unit and the display unit for producing one or more compressed video bits;
• and
• d. two or more lookup tables wherein the two or more lookup tables include a first table for P-macroblocks and a second table for l-macroblocks,
• wherein the encoder avoids computations where a transform coefficient before scaling is less than a computed threshold, wherein the computed threshold is selected based on one or more quantization parameters and one or more locations of coefficients.

A method of reducing computations in transform and scaling processes in video encoding processes, comprising:

• a. computing a plurality of discrete cosine transform thresholds based on one or more quantization parameters and one or more locations, wherein the plurality of thresholds are separately stored within a first table for P-macroblocks and a second table for l-macroblocks;
• b. comparing a selected threshold from the plurality of thresholds with a transform coefficient before scaling;
• and
• c. eliminating computations where the transform coefficient before scaling is less than the selected threshold.