Generic YUV Conversion

Generic YUV conversion provides the ability to convert any YUV format to any supported color space, using the YUV_PARAMS structure and adhering to the restrictions listed below. After defining the YUV format, you can proceed with the conversion normally, just like any other conversion. Use L_ClrConvert to perform the conversion and call L_ClrFree to free the conversion handle. Currently the conversion from any color space to Generic YUV is not supported.

Generic YUV conversion currently has the following restrictions:

1.	No sub-sampling of Y is supported
2.	The number of Y elements must be a multiple of both U, and V.
3.	With non-planar formats, vertical sub-sampling of Y, U, and V is not supported.
4.	No alignment supported in planar format; line width must not contain additional bytes.
5.	The horizontal sub-sampling periods of U, and V must be multiples of each other, and the vertical sub-sampling periods of U, and V must be multiples of each other.

Examples:

1.	Converting Y41P to RGB using Generic YUV Conversion:

L_VOID GenericY41PToRGB(L_UCHAR *pIn, L_UCHAR *pOut, L_INT nWidth, L_INT nHeight) 
{ 
   /*Declare a handle*/ 
   HANDLE hClrHandle; 
   /*Declare a CONVERSION_PARAMS structure*/ 
   CONVERSION_PARAMS cpParams; 
   /*Declare a YUV_PARAMS structure*/ 
   YUV_PARAMS yuvParams; 
/*Byte ordering of the format; for Y41P: 
   U0 Y0 V0 Y1 U4 Y2 V4 Y3 Y4 Y5 Y6 Y7 
   0    1    2    3    4    5    6    7    8   9    10  11 
Put the Y component order first, then the U and V last as follows: 
   Y positions: 1,3,5,7,8,9,10,11 
   U positions: 0,4 
   V positions: 2,6   */ 
   L_INT pOff[] = { 1, 3, 5, 7, 8, 9, 10, 11, 0, 4, 2, 6 }; 
   ZeroMemory(&cpParams, sizeof(CONVERSION_PARAMS)); 
   /*Determine the size of the structure*/ 
   yuvParams.uStructSize = sizeof(YUV_PARAMS); 
   /*Determine the horizontal sub-sampling of U */ 
   yuvParams.nUh = 4; 
   /*Determine the vertical sub-sampling of U */ 
   yuvParams.nUv = 1; 
   /*Determine the horizontal sub-sampling of V */ 
   yuvParams.nVh = 4; 
   /*Determine the vertical sub-sampling of V */ 
   yuvParams.nVv = 1; 
   /*Set the byte ordering*/ 
   yuvParams.pOffsets = pOff; 
   /*The YUV values range*/ 
   yuvParams.nRange = YUVRANGE_FULL; 
   /*This represents the macro pixels(smallest group of pixels allowed), which indicates how many actual pixels are in the macro pixel. This value is important only in non - planar format*/ 
   yuvParams.nMacroPixel = 8; 
   /*This is a Boolean value that represents the type of the YUV format (Planar = TRUE, or non - Planar = FALSE.)*/ 
   yuvParams.bPlanar = FALSE; 
   /*Fill the pYuvParams value with the address of the YUV_PARAMS structure*/ 
   cpParams.pYuvParams = &yuvParams; 
   /*Determine the size of CONVERSION_PARAMS*/ 
   cpParams.uStructSize = sizeof(CONVERSION_PARAMS); 
   /*Determine the type of conversion to be used in the conversion, for YUVGeneric, only use USE_BUILTIN*/ 
   cpParams.nMethod = USE_BUILTIN; 
   /*Determine the type of conversion to be activated. For YUVGeneric, 
   only USE_BUILTIN*/ 
   cpParams.nActiveMethod = USE_BUILTIN; 
   /*Initialize the conversion*/ 
   L_ClrInit(&hClrHandle, CCS_YUV, CCS_RGB, &cpParams); 
   /*Convert the buffers pIn to pOut*/ 
   L_ClrConvert(hClrHandle, pIn, pOut, nWidth, nHeight, 0, 0); 
   /*Free the handles*/ 
   L_ClrFree(hClrHandle); 
}

2.	Converting YVU9 (Planar) to RGB using Generic YUV Conversion:

L_VOID GenericYVU9ToRGB(L_UCHAR *pIn, L_UCHAR *pOut, L_INT nWidth, L_INT nHeight) 
{ 
   /*Declare a handle*/ 
   HANDLE hClrHandle; 
   /*Declare a CONVERSION_PARAMS structure*/ 
   CONVERSION_PARAMS cpParams; 
   /*Declare a YUV_PARAMS structure*/ 
   YUV_PARAMS yuvParams; 
/*This array of integers specifies the byte order of the yuv format. For planar formats it takes only a single value that represents the plane sequence in the buffer: 
   YUV, YVU, UYV, UVY, VYU, or VUY.*/ 
   L_INT pOff[] = { PLANAR_YVU }; /*PLANAR_YVU means the Y plane comes first in the buffer, then the V plane, and the U plane is last*/ 
   ZeroMemory(&cpParams, sizeof(CONVERSION_PARAMS)); 
   /*Determine the size of the structure*/ 
   yuvParams.uStructSize = sizeof(YUV_PARAMS); 
   /*Determine the horizontal sub-sampling of U*/ 
   yuvParams.nUh = 4; 
   /*Determine the vertical sub-sampling of U*/ 
   yuvParams.nUv = 4; 
   /*Determine the horizontal sub-sampling of V*/ 
   yuvParams.nVh = 4; 
   /*Determine the vertical sub-sampling of V*/ 
   yuvParams.nVv = 4; 
   /*This is a pointer to an integer. Pass the byte order array.*/ 
   yuvParams.pOffsets = pOff; 
   /*The range value determines the YUV range values. */ 
   yuvParams.nRange = YUVRANGE_FULL; 
   /*This represents the macro pixels(smallest group of pixels allowed) , which indicates how many actual pixels are in the macro pixel. This value is important only in non - planar format*/ 
   yuvParams.nMacroPixel = 16; 
   /*This is a Boolean value that represents the type of the YUV format (Planar, or non - Planar.)*/ 
   yuvParams.bPlanar = TRUE; 
   /*Pass the YUV_PARAMS structure address to the pYuvParams member of the CONVERSION_PARAMS structure.*/ 
   cpParams.pYuvParams = &yuvParams; 
   /*Determine the size of the CONVERSION_PARAMS structure.*/ 
   cpParams.uStructSize = sizeof(CONVERSION_PARAMS); 
   /*Determine the type of conversion to be used. For YUVGeneric, use only USE_BUILTIN*/ 
   cpParams.nMethod = USE_BUILTIN; 
   /*Determine the type of conversion to be activated. For YUVGeneric, use only USE_BUILTIN.*/ 
   cpParams.nActiveMethod = USE_BUILTIN; 
   /*Initialize the conversion*/ 
   L_ClrInit(&hClrHandle, CCS_YUV, CCS_RGB, &cpParams); 
   /*Convert the buffers pIn to pOut*/ 
   L_ClrConvert(hClrHandle, pIn, pOut, nWidth, nHeight, 0, 0); 
   /*Free the handles*/ 
   L_ClrFree(hClrHandle); 
}