Method and apparatus for implementing 4:2:0 to 4:2:2 and 4:2:2 to 4:2:0 color space conversion

Abstract

A method and circuit are provided for color space conversion of Y (luminance) and UV (chrominance) components from a planar YUV 4:2:0 format to an interleaved, or packed YUV 4:2:2 format, and from an interleaved, or packed YUV 4:2:2 format to a planar YUV 4:2:0 format. The method for both conversions includes reading source data, interpolating the sampled YUV component values, and performing a pass to thereby write the converted YUV component values in three passes, one pass for all values of the respective YUV components.

What is claimed is:  
     
         1 . A method comprising: 
 performing conversion of YUV (luminance and chrominance) components by use of a number of successive passes for each of the YUV components, wherein a successive pass of the number of successive passes for one component of the YUV components is separate from successive passes of the number of successive passes for other components of the YUV components, wherein a successive pass of the one component of the YUV components comprises: 
 scaling the one component of the YUV components to a destination resolution;  
 aligning the one component with a sampling point of a destination format; and  
 writing the one component in the destination format.  
   
     
     
         2 . The method of  claim 1 , wherein performing conversion of YUV (luminance and chrominance) components by use of successive passes for each of the YUV components comprises performing conversion of YUV components from source planar YUV 4:2:0 format to destination packed YUV 4:2:2 format with the same or different surface resolutions.  
     
     
         3 . The method of  claim 1 , wherein performing conversion of YUV (luminance and chrominance) components by use of successive passes for each of the YUV components comprises performing conversion of YUV components from source packed YUV 4:2:2 format to destination planar YUV 4:2:0 format with the same or different surface resolutions.  
     
     
         4 . The method of  claim 1 , wherein the scaling, the aligning and the writing occur subsequent to decoding of source data that includes the YUV components.  
     
     
         5 . The method of  claim 1 , wherein writing the one component in the destination format comprises writing the one component in the destination format based on a byte masking operation.  
     
     
         6 . A method comprising: 
 performing color space conversion of color components, which comprises performing color space conversion of a first component of the color components prior to performing color space conversion of a second component of the color components,    wherein performing color space conversion of the first component comprises: 
 scaling a first component of the color components to a destination resolution to generate a first scaled component;  
 aligning the first scaled component with a sampling point of a destination format; and  
 writing the first scaled component in the destination format;  
   wherein performing color space conversion of the second component comprises: 
 scaling a second component of color components to the destination resolution to generate a second scaled component;  
 aligning the second scaled component with a sampling point of the destination format; and  
 writing said second scaled component in the destination format.  
   
     
     
         7 . The method of  claim 6 , wherein scaling the first component comprises scaling and sampling the first component based on an interpolation/conversion operation.  
     
     
         8 . The method of  claim 6 , wherein scaling the second component comprises scaling and sampling the second component based on an interpolation/conversion operation.  
     
     
         9 . An apparatus comprising: 
 a memory; and    a filter to perform a conversion operation for color components, wherein the conversion operation for one component of the color components is separate from the conversion operation for other components of the color components, wherein the conversion operation for the one component of the color components comprises a scale operation, an align operation and a write operation, wherein the filter is to generate a scaled color component based on the scale operation of the one component from a source resolution to a destination resolution, the filter to align the scaled color component with a sampling point of a destination format based on the align operation, the filter to write the scaled color component in the destination format into the memory.    
     
     
         10 . The apparatus of  claim 9 , wherein the color components are YUV (luminance and chrominance) components, wherein the filter is to perform the conversion operation from a planar YUV 4:2:0 format to a packed YUV 4:2:2 format.  
     
     
         11 . The apparatus of  claim 9 , wherein the color components are YUV (luminance and chrominance) components, wherein the filter is to perform the conversion operation from a packed YUV 4:2:2 format to planar YUV 4:2:0 format.  
     
     
         12 . A system comprising: 
 a universal serial bus port to receive source data that includes components of a source format within a color space;    a memory to store the components of the source format; and    a filter to convert the components of the source format to components of a destination format, wherein conversion for one component is separate for conversion of the other components, the conversion comprising a scale function, an align function and a write function.    
     
     
         13 . The system of  claim 12 , wherein the filter is to generate a scaled color component based on the scale function of the one component from the source format to the destination format.  
     
     
         14 . The system of  claim 13 , wherein the filter is to align the scaled color component with a sampling point of the destination format based on the align function.  
     
     
         15 . The system of  claim 14 , wherein the filter is to write the scaled color component in the destination format into the memory.  
     
     
         16 . A machine-readable medium that provides instructions, which when executed by a machine, cause said machine to perform operations comprising: 
 performing conversion of YUV (luminance and chrominance) components by use of a number of successive passes for each of the YUV components, wherein a successive pass of the number of successive passes for one component of the YUV components is separate from successive passes of the number of successive passes for other components of the YUV components, wherein a successive pass of the one component of the YUV components comprises: 
 scaling the one component of the YUV components to a destination resolution;  
 aligning the one component with a sampling point of a destination format; and  
 writing the one component in the destination format.  
   
     
     
         17 . The machine-readable medium of  claim 16 , wherein performing conversion of YUV (luminance and chrominance) components by use of successive passes for each of the YUV components comprises performing conversion of YUV components from source planar YUV 4:2:0 format to destination packed YUV 4:2:2 format with the same or different surface resolutions.  
     
     
         18 . The machine-readable medium of  claim 16 , wherein performing conversion of YUV (luminance and chrominance) components by use of successive passes for each of the YUV components comprises performing conversion of YUV components from source packed YUV 4:2:2 format to destination planar YUV 4:2:0 format with the same or different surface resolutions.  
     
     
         19 . The machine-readable medium of  claim 16 , wherein the scaling, the aligning and the writing occur subsequent to decoding of source data that includes the YUV components.  
     
     
         20 . The machine-readable medium of  claim 16 , wherein writing the one component in the destination format comprises writing the one component in the destination format based on a byte masking operation.  
     
     
         21 . A machine-readable medium that provides instructions, which when executed by a machine, cause said machine to perform operations comprising: 
 performing color space conversion of color components, which comprises performing color space conversion of a first component of the color components prior to performing color space conversion of a second component of the color components,    wherein performing color space conversion of the first component comprises: 
 scaling a first component of the color components to a destination resolution to generate a first scaled component;  
 aligning the first scaled component with a sampling point of a destination format; and  
 writing the first scaled component in the destination format;  
   wherein performing color space conversion of the second component comprises: 
 scaling a second component of color components to the destination resolution to generate a second scaled component;  
 aligning the second scaled component with a sampling point of the destination format; and  
 writing said second scaled component in the destination format.  
   
     
     
         22 . The machine-readable medium of  claim 21 , wherein scaling the first component comprises scaling and sampling the first component based on an interpolation/conversion operation.  
     
     
         23 . The machine-readable medium of  claim 21 , wherein scaling the second component comprises scaling and sampling the second component based on an interpolation/conversion operation.