Method and apparatus for performing video image decoding

Abstract

In one embodiment, a method of performing video image decoding includes the following. A compressed video image is downsampled in the frequency domain. The downsampled video image is inverse transformed. Motion compensation for the downsampled image is performed in the spatial domain.

1 . A method of performing video image decoding comprising: 
 downsampling a compressed video image in the frequency domain;    inverse transforming the downsampled video image; and    performing motion compensation for the downsampled image in the spatial domain.    
     
     
         2 . The method of  claim 1 , wherein the compressed video image in the frequency domain comprises a discrete cosine transform (DCT) image.  
     
     
         3 . The method of  claim 2 , wherein the DCT image is stored as a DCT image that complies with an MPEG specification.  
     
     
         4 . The method of  claim 3 , wherein the DCT image is stored as a frame type image.  
     
     
         5 . The method of  claim 4 , wherein the motion compensation data signals are stored as frame prediction type motion compensation.  
     
     
         6 . The method of  claim 3 , wherein the DCT image is stored as a field type image.  
     
     
         7 . The method of  claim 6 , wherein the motion compensation data signals are stored as field prediction type motion compensation.  
     
     
         8 . The method of  claim 1 , and further comprising displaying the downsampled spatial image so that resulting non-uniform vertical spacing of data signal lines in the downsampled spatial image appear substantially uniform on a computer monitor.  
     
     
         9 . The method of  claim 1 , wherein the downsampling is performed using an integer ratio.  
     
     
         10 . The method of  claim 1 , wherein performing motion compensation comprises scaling motion vectors in accordance with the downsamping ratio.  
     
     
         11 . The method of  claim 10 , wherein motion vector scaling comprises implementing an interpolation operation.  
     
     
         12 . The method of  claim 11 , wherein motion vector scaling comprises implementing a bilinear interpolation operation.  
     
     
         13 . The method of  claim 12 , wherein the bilinear interpolation operation is implemented on 3D pipeline hardware.  
     
     
         14 . The method of  claim 1 , wherein downsampling comprises implementing a linear filter as a bilinear interpolation operation.  
     
     
         15 . The method of  claim 14 , wherein the bilinear interpolation operation is implemented on 3D pipeline hardware.  
     
     
         16 . A method of performing video image decoding comprising: 
 inverse transforming a compressed video image;    downsamping the inverse transformed image in the spatial domain; and    performing motion compensation for the downsampled image in the spatial domain.    
     
     
         17 . The method of  claim 16 , wherein the compressed video image comprises a discrete cosine transform (DCT) image.  
     
     
         18 . The method of  claim 17 , wherein the DCT image is stored as a DCT image that complies with an MPEG specification.  
     
     
         19 . The method of  claim 18 , wherein the DCT image comprises macroblocks stored as frame macroblocks and macroblocks stored as field macroblocks.  
     
     
         20  The method of  claim 19 , and further comprising: converting the frame macroblocks to field macroblocks prior to downsampling in the spatial domain.  
     
     
         21 . The method of  claim 19 , wherein the motion compensation data signals are stored as field prediction type motion compensation.  
     
     
         22 . The method of  claim 16 , wherein performing motion compensation comprises scaling motion vectors in accordance with a downscaling ratio.  
     
     
         23 . The method of  claim 22 , wherein motion vector scaling comprises implementing an interpolation operation.  
     
     
         24 . The method of  claim 23 , wherein motion vector scaling comprises implementing a bilinear interpolation operation.  
     
     
         25 . The method of  claim 24 , wherein the bilinear interpolation operation is implemented on 3D pipeline hardware.  
     
     
         26 . The method of  claim 16 , wherein downsampling comprises implementing a linear filter as a bilinear interpolation operation.  
     
     
         27 . The method of  claim 26 , wherein the bilinear interpolation operation is implemented on 3D pipeline hardware.  
     
     
         28 . An article comprising: a storage medium, having stored thereon instructions, that when executed by a platform, result in the following: 
 downsampling a compressed video image in the frequency domain;    inverse transforming the downsampled video image; and    performing motion compensation for the downsampled image in the spatial domain.    
     
     
         29 . The article of  claim 28 , wherein the instructions, when executed further result in the compressed video image in the frequency domain comprising a discrete cosine transform (DCT) image.  
     
     
         30 . The article of  claim 29 , wherein the instructions, when executed, further result in the DCT image being stored as a DCT image that complies with an MPEG specification.  
     
     
         31 . The article of  claim 28 , wherein the instructions, when executed, further result in: displaying the downsampled spatial image so that resulting non-uniform vertical spacing of data signal lines in the downsampled spatial image appear substantially uniform on a computer monitor.  
     
     
         32 . An article comprising: a storage medium, having stored thereon instructions, that when executed by a platform, result in the following: 
 inverse transforming a compressed video image;    downsamping the inverse transformed image in the spatial domain; and    performing motion compensation for the downsampled image in the spatial domain.    
     
     
         33 . The article of  claim 32 , wherein the instructions, when executed further result in the compressed video image in the frequency domain comprising a discrete cosine transform (DCT) image.  
     
     
         34 . The article of  claim 33 , wherein the instructions, when executed, further result in the DCT image being stored as a DCT image that complies with an MPEG specification.