Xilinx Processor IP Library

Software Drivers

xscaler.c File Reference

Detailed Description

This is main code of Xilinx MVI Video Scaler device driver. The Scaler device converts a specified rectangular area of an input digital video image from one original sampling grid to a desired target sampling grid. Please see xscaler.h for more details of the driver.

 MODIFICATION HISTORY:

 Ver	Who	 Date	  Changes
 ----- ---- -------- -------------------------------------------------------
 1.00a xd   02/10/09 First release
 2.00a xd   12/14/09 Updated doxygen document tags
 4.01a cw   06/27/12 Updated tcl file with new parameter names (num_x_taps)
                      Updated mdd file with updated supported_peripherals field.
 4.02a mpv  03/11/13 Updated the Driver to select the correct coeff bin.
                     Changed RegValue variable to a volatile type
                     Removed 10.x patch in the Tcl file
 4.03a mpv  05/28/13 Fixed version limit in MDD file
                     Updated the Driver input, output and aperture size mask
 5.00a mpv  12/13/13 Updated to dynamic coeff generation to reduce driver size

#include "xscaler.h"
#include "xenv.h"
#include "xil_io.h"
#include "xil_assert.h"

Utility Macros

#define round(x)   ((x) >= 0 ? (s32)((x) + 0.5) : (s32)((x) - 0.5))

Functions

s16 * XScaler_GenCoefTable (u32 Tap, u32 Phase)
int XScaler_CfgInitialize (XScaler *InstancePtr, XScaler_Config *CfgPtr, u32 EffectiveAddr)
int XScaler_SetAperture (XScaler *InstancePtr, XScalerAperture *AperturePtr)
void XScaler_GetAperture (XScaler *InstancePtr, XScalerAperture *AperturePtr)
void XScaler_SetPhaseNum (XScaler *InstancePtr, u16 VertPhaseNum, u16 HoriPhaseNum)
void XScaler_GetPhaseNum (XScaler *InstancePtr, u16 *VertPhaseNumPtr, u16 *HoriPhaseNumPtr)
void XScaler_SetStartFraction (XScaler *InstancePtr, XScalerStartFraction *StartFractionPtr)
void XScaler_GetStartFraction (XScaler *InstancePtr, XScalerStartFraction *StartFractionPtr)
void XScaler_GetCoeffBankSharingInfo (XScaler *InstancePtr, u8 *ChromaFormat, u8 *ChromaLumaShareCoeff, u8 *HoriVertShareCoeff)
s16 * XScaler_CoefValueLookup (u32 InSize, u32 OutSize, u32 Tap, u32 Phase)
void XScaler_LoadCoeffBank (XScaler *InstancePtr, XScalerCoeffBank *CoeffBankPtr)
void XScaler_SetActiveCoeffSet (XScaler *InstancePtr, u8 VertSetIndex, u8 HoriSetIndex)
void XScaler_GetActiveCoeffSet (XScaler *InstancePtr, u8 *VertSetIndexPtr, u8 *HoriSetIndexPtr)

Variables

u16 XScaler_CoefficientBinScalingFactors [XSCL_NUM_COEF_BINS]

Define Documentation

#define round (  x   )     ((x) >= 0 ? (s32)((x) + 0.5) : (s32)((x) - 0.5))
 

This macro calculates the integral value nearest to x rounding half-way cases away from zero, regardless of the current rounding direction.

Parameters:
x has a float type value
Returns:
the integral value nearest to x rounding half-way cases away from zero, regardless of the current rounding direction.
Note:
C-style signature: s32 round(float x);

Function Documentation

int XScaler_CfgInitialize (  XScaler *  InstancePtr,
XScaler_Config *  CfgPtr,
u32  EffectiveAddr
) 
 

This function initializes a Scaler device. This function must be called prior to using a Scaler device. Initialization of a Scaler includes setting up the instance data, and ensuring the hardware is in a quiescent state.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
CfgPtr points to the configuration structure associated with the Scaler device.
EffectiveAddr is the base address of the device. If address translation is being used, then this parameter must reflect the virtual base address. Otherwise, the physical address should be used.
Returns:
XST_SUCCESS

s16* XScaler_CoefValueLookup (  u32  InSize,
u32  OutSize,
u32  Tap,
u32  Phase
) 
 

This function returns the pointer to the coefficients for a scaling operation given input/output sizes and the Tap and Phase numbers.

Parameters:
InSize indicates the size (width or height) of the input video.
OutSize indicates the size (width or height) of the output video.
Tap indicates the Tap number.
Phase indicates the Phase number.
Returns:
The points to the coefficients ready for the scaling operation.
Note:
None.

s16* XScaler_GenCoefTable (  u32  Tap,
u32  Phase
) 
 

XScaler_GenCoefTable generates XScaler_coef_table containing the coefficient values for scaling operations

void XScaler_GetActiveCoeffSet (  XScaler *  InstancePtr,
u8 *  VertSetIndexPtr,
u8 *  HoriSetIndexPtr
) 
 

This function fetches the indexes of active vertical and horizontal coefficient sets being used by a Scaler device.

Each coefficient set contains 4 banks: Horizontal Luma, Horizontal Chroma, Vertical Luma and Vertical Chroma. The horizontal part is independent from the vertical part and the Scaler device supports using the horizontal part of one coefficient set w/ the vertical part of a different coefficient set.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
VertSetIndexPtr points to the index of the active coefficient set in which the vertical part is being used by the Scaler device after this function returns.
HoriSetIndexPtr points to the index of the active coefficient set in which the horizontal part is being used by the Scaler device after this function returns.
Returns:
None.
Note:
None.

void XScaler_GetAperture (  XScaler *  InstancePtr,
XScalerAperture *  AperturePtr
) 
 

This function gets aperture of a Scaler device. The aperture setting consists of input video aperture and output video size.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
AperturePtr points to the aperture structure to store the current Scaler device setting after this function returns.
Returns:
None

void XScaler_GetCoeffBankSharingInfo (  XScaler *  InstancePtr,
u8 *  ChromaFormat,
u8 *  ChromaLumaShareCoeff,
u8 *  HoriVertShareCoeff
) 
 

This function fetches the color space format and coefficient bank sharing decisions made on a Scaler device at build-time.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
ChromaFormat points to an 8-bit variable that will be assigned with the Chroma format chosen for the Scaler device at the build time after this function returns. Please use XSCL_CHROMA_FORMAT_* defined in xscaler_hw.h to interpret the variable value.
ChromaLumaShareCoeff points to an 8-bit variable that will be assigned by this function with the decision value on coefficient bank sharing between Chroma and Luma filter operations. The decision is made for the Scaler device at build time and can NOT be changed at run-time. Value 0 indicates that each of Chroma and Luma filter operations has its own coefficient bank. Value 1 indicates that Chroma and Luma filter operations share one common coefficient bank.
HoriVertShareCoeff points to an 8-bit variable that will be assigned by this function with the decision value on coefficient bank sharing between Horizontal and Vertical filter operations. The decision is made for the Scaler device at build time and can NOT be changed at run-time. Value 0 indicates that each of Horizontal and Vertical filter operations has its own coefficient bank. Value 1 indicates that Horizontal and Vertical filter operations share one common coefficient bank.
Returns:
None.
Note:
!!!IMPORTANT!!!

The application of this function is responsible for loading the correct number of coefficient banks in the proper sequence order. The number of coefficient banks to load and the proper loading sequence totally depends on the values of the output parameters of this function. Please use the table below as reference.

 ChromaFormat ChromaLumaShareCoeff HoriVertShareCoeff # of      sequence
                                                      coeff     of
                                                      banks     loading
                                                      to load   coeff
                                                                banks
 ------------ -------------------- ------------------ --------  -------------
 YUV420       1                    1                  1         1.Single bank
 ------------ -------------------- ------------------ --------  -------------
 YUV420       1                    0                  2         1.Hori bank
                                                                2.Vert bank
 ------------ -------------------- ------------------ --------  -------------
 YUV420       0                    1                  2         1.Luma bank
                                                                2.Chroma bank
 ------------ -------------------- ------------------ --------  -------------
 YUV420       0                    0                  4         1.Hori Luma
                                                                2.Hori Chroma
                                                                3.Vert Luma
                                                                4.Vert Chroma
 ------------ -------------------- ------------------ --------  -------------
 YUV422       1                    1                  1         1.Single bank
 ------------ -------------------- ------------------ --------  -------------
 YUV422       1                    0                  2         1.Hori bank
                                                                2.Vert bank
 ------------ -------------------- ------------------ --------  -------------
 YUV422       0                    1                  2         1.Luma bank
                                                                2.Chroma bank
 ------------ -------------------- ------------------ --------  -------------
 YUV422       0                    0                  4         1.Hori Luma
                                                                2.Hori Chroma
                                                                3.Vert Luma
                                                                4.Vert Chroma
 ------------ -------------------- ------------------ --------  -------------
 YUV444       Always 1             1                  1         1.Single bank
 ------------ -------------------- ------------------ --------  -------------
 YUV444       Always 1             0                  2         1.Hori bank
                                                                2.Vert bank
 ------------ -------------------- ------------------ --------  -------------

void XScaler_GetPhaseNum (  XScaler *  InstancePtr,
u16 *  VertPhaseNumPtr,
u16 *  HoriPhaseNumPtr
) 
 

This function gets the numbers of vertical and horizontal phases currently used by a Scaler device.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
VertPhaseNumPtr will point to the number of vertical phases used after this function returns.
HoriPhaseNumPtr will point to the number of horizontal phases used after this function returns.
Returns:
None

void XScaler_GetStartFraction (  XScaler *  InstancePtr,
XScalerStartFraction *  StartFractionPtr
) 
 

This function gets Luma and Chroma start fractional values currently used by a Scaler device.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
StartFractionPtr is a pointer to a start fractional value structure to be populated with the fractional values after this function returns.
Returns:
None

void XScaler_LoadCoeffBank (  XScaler *  InstancePtr,
XScalerCoeffBank *  CoeffBankPtr
) 
 

This function loads a coefficient bank to the Scaler core. A complete coefficient set contains 4 banks (if Luma, Chroma, Horizontal and Vertical filter operations do not share common banks. For more details see XScaler_GetCoeffBankSharingInfo()): Horizontal Luma, Horizontal Chroma, Vertical Luma and Vertical Chroma. all 4 banks must be loaded back to back in the order listed here. The caller is responsible for ensuring the sequence and this function does not check it.

An example sequence to load an whole coefficient set is like: 

	   XScaler_LoadCoeffBank(&Scaler, &HoriLumaCoeffBank);
	   XScaler_LoadCoeffBank(&Scaler, &HoriChromaCoeffBank);
	   XScaler_LoadCoeffBank(&Scaler, &VertLumaCoeffBank);
	   XScaler_LoadCoeffBank(&Scaler, &VertChromaCoeffBank);

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
CoeffBankPtr is a pointer to a coefficient bank that is to be loaded
Returns:
None

void XScaler_SetActiveCoeffSet (  XScaler *  InstancePtr,
u8  VertSetIndex,
u8  HoriSetIndex
) 
 

This function chooses the active vertical and horizontal coefficient sets to be used by a Scaler device.

Each coefficient set contains 4 banks: Horizontal Luma, Horizontal Chroma, Vertical Luma and Vertical Chroma. The horizontal part is independent from the vertical part and the Scaler device supports using the horizontal part of one coefficient set w/ the vertical part of a different coefficient set.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on
VertSetIndex indicates the index of the coefficient set in which the vertical part will be used by the Scaler device. Valid value is from 0 to (the number of the coefficient sets implemented by the Scaler device - 1)
HoriSetIndex indicates the index of the coefficient set in which the horizontal part will be used by the Scaler device. Valid value is from 0 to (the number of the coefficient sets implemented by the Scaler device - 1)
Returns:
None.
Note:
None.

int XScaler_SetAperture (  XScaler *  InstancePtr,
XScalerAperture *  AperturePtr
) 
 

This function sets up aperture of a Scaler device. The aperture setting consists of input video aperture and output video size. This function calculates the scale factor accordingly based on the aperture setting and sets up the Scaler appropriately.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
AperturePtr points to the aperture setting structure to set up the Scaler device.
Returns:
XST_SUCCESS

void XScaler_SetPhaseNum (  XScaler *  InstancePtr,
u16  VertPhaseNum,
u16  HoriPhaseNum
) 
 

This function sets the numbers of vertical and horizontal phases to be used by a Scaler device.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
VertPhaseNum is the number of vertical phase to set to
HoriPhaseNum is the number of horizontal phase to set to
Returns:
None

void XScaler_SetStartFraction (  XScaler *  InstancePtr,
XScalerStartFraction *  StartFractionPtr
) 
 

This function sets up Luma and Chroma start fractional values used by a Scaler device.

Parameters:
InstancePtr is a pointer to the Scaler device instance to be worked on.
StartFractionPtr is a pointer to a start fractional value set to be used.
Returns:
None

Variable Documentation

u16 XScaler_CoefficientBinScalingFactors[XSCL_NUM_COEF_BINS]
 

XScaler_CoefficientsBinScalingFactors contains scaling factors calculated using (Output_Size * 10000 / Input_Size). This table could help find the index of coefficient Bin given an input size and a output size.

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