US 2002/0154696 A1 · Systems and methods for MPEG subsample decoding

Abstract

Decimating MPEG or other video data by subsampling the output of an inverse discrete cosine transform (IDCT) module. The decimation process is useful for reducing the volume of data that must be processed to display images on a display device, particularly when the volume of video data received at the decoder is greater than the amount needed to take advantage of the resolution of the display device. For example, high definition television data can be decimated for display on a standard television display device or in a picture-in-picture window, thereby reducing the amount of processing resources needed at the decoder and reducing the size of the frame buffers. Subsampling the output of the IDCT module reduces the volume of data and, for relatively static or constant pans, there is not a significant compounded loss of image quality as successive frames are decoded.

Claims23

Dependent claims

In a system for processing MPEG data in preparation for displaying video images encoded in the MPEG data, a method for subsampling the MPEG data to reduce the volume of video data processed to display the video images, comprising the acts of:

processing one or more motion vectors in order to produce coordinates for fetching prediction data from a previously decoded and subsampled reference frame;
processing the reference frame and the one or more motion vectors of the MPEG data using a frame prediction module to generate predicted subsampled frame data;
processing frequency coefficients of the MPEG data using an inverse discrete cosine transformer (IDCT) to generate IDCT output data;
decimating the IDCT output data by a selected factor to generate decimated IDCT output data;
and
summing the predicted subsampled frame data and the decimated IDCT output data to generate video images encoded in a reduced volume of video data.

3 more elements

A computer program product for implementing, in a system for processing MPEG data in preparation for displaying video images encoded in the MPEG data, a method for subsampling the MPEG data to reduce the volume of video data processed to display the video images, the computer program product comprising:

a computer-readable medium carrying computer-executable instructions, that when executed at the system, cause the system to perform the acts of:
processing one or more motion vectors in order to produce coordinates for fetching prediction data from a previously decoded and subsampled reference frame;
processing the reference frame and the one or more motion vectors of the MPEG data using a frame prediction module to generate predicted subsampled frame data;
processing frequency coefficients of the MPEG data using an inverse discrete cosine transformer (IDCT) to generate IDCT output data;
decimating the IDCT output data by a selected factor to generate decimated JDCT output data;
and
summing the subsampled predicted frame data and the decimated IDCT output data to generate video images encoded in a reduced volume of video data.

4 more elements

Dependencies are inferred from the claim text.

Systems and methods for MPEG subsample decoding

Life of this patent

Systems and methods for MPEG subsample decoding

Life of this patent

Abstract

Claims23