Generic YUV conversion (Visual Basic)

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 subsampling periods of U, and V must be multiples of each other, and the vertical subsampling periods of U, and V must be multiples of each other.

Examples

1. Converting Y41P to RGB using Generic YUV Conversion:

   Function GenericY41PToRGB(YUVData() As Byte, RGBData() As Byte, nWidth As Integer, nHeight As Integer) As Integer 
       Dim ret As Integer 
       Dim ClrHandle As Long 
       Dim cnvParam As CONVERSION_PARAMS 
       Dim pOff(12) As Long 
       pOff(0) = 1 
       pOff(1) = 3 
       pOff(2) = 5 
       pOff(3) = 7 
       pOff(4) = 8 
       pOff(5) = 9 
       pOff(6) = 10 
       pOff(7) = 11 
       pOff(8) = 0 
       pOff(9) = 4 
       pOff(10) = 2 
       pOff(11) = 6 
       '(1,3,5,7,8,9,10,11,0,4,2,6) 
       Dim YUVParamas As LPYUV_PARAMS 
       With YUVParamas 
          .uStructSize = Len(YUVParamas) 
          .nMask = 0 
          .nUh = 4 
          .nUv = 1 
          .nVh = 4 
          .nVv = 1 
          .pOffsets = VarPtr(pOff(0)) 
          .nMacroPixel = 8 
          .nRange = YUVRANGE_FULL 
          .bPlanar = 0 
       End With 
       cnvParam.uStructSize = Len(cnvParam) 
       cnvParam.nQuantization = 0 
       cnvParam.nMethod = USE_BUILTIN 
       cnvParam.nActiveMethod = USE_BUILTIN 
       cnvParam.pCmykParams = 0 
       cnvParam.pLabParams = 0 
       cnvParam.pYuvParams = VarPtr(YUVParamas) 
       cnvParam.sInputProfile(0) = 0 
       cnvParam.sOutputProfile(0) = 0 
       ret = L_ClrInit (ClrHandle, CCS_YUV, CCS_RGB, cnvParam) 
       ret = L_ClrConvert (ClrHandle, YUVData(0), RGBData(0), nWidth, nHeight, 0, 0) 
       ret = L_ClrFree (ClrHandle) 
       GenericY41PToRGB = ret 
    End Function 

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

   Function GenericYVU9ToRGB(YUVData() As Byte, RGBData() As Byte, nWidth As Integer, nHeight As Integer) As Integer 
       Dim ret As Integer 
       Dim ClrHandle As Long 
       Dim cnvParam As CONVERSION_PARAMS 
       Dim pOff(0) As Long 
       pOff(0) = PLANAR_YVU 
       Dim YUVParamas As LPYUV_PARAMS 
       With YUVParamas 
          .uStructSize = Len(YUVParamas) 
          .nMask = 0 
          .nUh = 4 
          .nUv = 1 
          .nVh = 4 
          .nVv = 1 
          .pOffsets = VarPtr(pOff(0)) 
          .nMacroPixel = 8 
          .nRange = YUVRANGE_FULL 
          .bPlanar = 1 
       End With 
       cnvParam.uStructSize = Len(cnvParam) 
       cnvParam.nQuantization = 0 
       cnvParam.nMethod = USE_BUILTIN 
       cnvParam.nActiveMethod = USE_BUILTIN 
       cnvParam.pCmykParams = 0 
       cnvParam.pLabParams = 0 
       cnvParam.pYuvParams = VarPtr(YUVParamas) 
       cnvParam.sInputProfile(0) = 0 
       cnvParam.sOutputProfile(0) = 0 
       ret = L_ClrInit (ClrHandle, CCS_YUV, CCS_RGB, cnvParam) 
       ret = L_ClrConvert (ClrHandle, YUVData(0), RGBData(0), nWidth, nHeight, 0, 0) 
       ret = L_ClrFree (ClrHandle) 
       GenericYVU9ToRGB = ret 
    End Function 

See Also

Introduction

Bitmap Conversion Options

Color Conversion C API Function Groups

Getting Started