Decompression processor for video applications

• US 5,809,174 A
• Filed: 10/15/1996
• Issued: 09/15/1998
• Est. Priority Date: 04/13/1993
• Status: Expired due to Term

• Current Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Original Assignee: C-Cube Corporation (Broadcom, Inc.)
• Inventors: Galbi, David E., Liao, Frank H., Tse, Yvonne C., Purcell, Stephen C.
• Primary Examiner(s): Couso, Jose L.
• Application Number:
  US08/730,252
• Time in Patent Office: 700 Days
• Field of Search: 348/412, 348/416, 348/413, 348/441, 348/446, 348/448, 348/451, 348/452, 348/459, 348/464, 348/415, 348/420, 348/396, 348/397, 382/232, 382/236
• US Class Current: 382/236
• CPC Class Codes: H03M 7/425 for the decoding process only
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/43 Hardware specially adapted for motion estimation or compensation
• CPC Class Codes: H04N 19/433 characterised by techniques for memory access
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/42692 for reading from or writing on a volatile storage medium, e.g. Random Access Memory [RAM]

Abstract

A motion compensation structure and a method are provided for decoding interframe coded video data using motion vectors. The motion compensation structure includes a filter for resampling the pixel data in both vertical and horizontal directions, a prediction memory structure and a weighted adder structure. In one embodiment of the present invention, a weighted adder structure and a method are provided for performing bilinear interpolation of two values using multiplexers and an multiple-input adder.

Claims

1. An apparatus for decoding interframe coded current video data, using motion vectors (x, y) coded with respect to reference video data, comprising:

means for receiving said current video data;

means for receiving said reference video data;

a filter, coupled to said means for receiving said reference video data, for resampling said reference video data in x and y directions, said filter providing resampled video data according to positions specified by said motion vectors, wherein said positions include fractional screen locations with respect to screen locations of said reference video data;

a weighted adder, having a first set of input terminals coupled to receive said resampled video data from said filter, and a second set of input terminals, for interpolating said resampled reference video data, during a first time period, and for summing said interpolated reference video data, received at said second set of input terminals, with said current video data, during a second time period; and

a pixel memory for coupled to said weighted adder to receive for storage said interpolated reference video data during said first time period, and for providing at said second set of input terminals of said weighted adder said interpolated reference video during said second time period.

2. An apparatus as in claim 1, wherein said filter further comprises:

a 2-tap filter for resampling in the horizontal direction; and

a 3-tap filter for resampling in the vertical direction.

3. An apparatus as in claim 1, wherein said motion vector comprises first and second portions, said first portion being provided to said filter for resampling, said apparatus further comprising means for computing the sum of the screen locations of said reference data and the screen locations of said current video data, offset by said second portion of said motion vector.

4. A method for decoding interframe coded current video data, said video data representing intensities of pixels, using motion vectors (x,y) coded with respect to reference video data, comprising:

receiving said reference video data, during a first time period;

receiving said video data, during a second time period;

during said first time period, providing a filter for resampling said reference video data in x and y directions, said filter providing resampled video data according to positions specified by said motion vectors, wherein said positions include fractional screen locations with respect to locations of said reference video data;

interpolating said resampled reference video data, during said first time period;

storing in a pixel memory said interpolated reference video data during said first time period;

during said second time period, retrieving said interpolated reference video data from said pixel memory for summing in said weighted adder with said current video data.

5. A method as in claim 4, wherein said filter providing step further comprises:

providing a 2-tap filter for resampling in the horizontal direction; and

providing a 3-tap filter for resampling in the vertical direction.

6. A method as in claim 4, wherein said motion vector comprises first and second portions, said first portion being provided to said filter for resampling, said method further comprising the step of computing the sum of the screen locations of said reference data and the screen locations of said current video data, offset by said second portion of said motion vector.