decoderquad.h

LDPC码的实现,包括编码器和解码器,使用了DCT.

// decoderQuad.h

//------------------------------------------------------------
// David Chen*, David Varodayan, Markus Flierl, Bernd Girod
// Image, Video, and Multimedia Systems Group
// Information Systems Laboratory
// Stanford University
//
// *Contact: [e-mail]
//------------------------------------------------------------

#ifndef _DECODERQUAD_H_
#define _DECODERQUAD_H_
#include "common.h"
#include <ChenImage.h>

// [[ * ]] indicates dimension or length

/* -----------------------------------------------------------------------------
 * pixelQuads_decodeFrameYUV
 * -----------------------------------------------------------------------------
 * Decodes a YUV [4:2:0] frame using LDPC parity bitstreams and side 
 * information frame.
 *
 * Inputs:
 * const CodingOption* pOption
 *		structure containing coding options
 * const short* pSideInfoFrame[3]
 *		previously received frame serving as side information
 *		Y component [[ HEIGHT x WIDTH ]]
 *		U component [[ HEIGHT_QUAD x WIDTH_QUAD ]]
 *		V component [[ HEIGHT_QUAD x WIDTH_QUAD ]]
 * const unsigned char* pAccumSyndromeQuads[6]
 *		LDPC parity bitstreams [[ BITS_QUAD ]]
 *		four streams for four quadrants of luminance component
 *		two streams for two chrominance components
 * const short* pScaledQArray
 *		table for quantization of DCT coefficients [[ NUM_COEFFS ]]
 * const float fRateLowerBoundQuads[6]
 *		initial rates at which to start decoding
 *		four rate values for four quadrants of luminance component
 *		two rate values for two chrominance components
 *		bits-per-original-bit
 * const float* pLaplacianQuads
 *		Laplacian parameter sets [[ NUM_COEFFS ]]
 *		four sets for four quadrants of luminance component
 *		two sets for two chrominance components
 * const char* pLadderFile
 *		name of ladder file
 * const short* pOracleShiftsXQuads
 * const short* pOracleShiftsYQuads
 *		blockwise oracle motion fields 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		four fields for four quadrants of luminance component
 *		two fields for two chrominance components
 *		used only for motion oracle mode
 *
 * Outputs:
 * short* pDecodedFrame[3]
 *		decoded frame, same dimensions as side information frame
 * float pRate[6]
 *		final rates required for successful decoding
 *		four rate values for four quadrants of luminance component
 *		two rate values for two chrominance components
 *		bits-per-original-bit
 * short* pDecodedShiftsX[6]
 * short* pDecodedShiftsY[6]
 *		decoded blockwise motion fields 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		most-probable motion candidate chosen
 *		four fields for four quadrants of luminance component
 *		two fields for two chrominance components
 * float* pDecodedShiftProb[6]
 *		decoded blockwise max probabilities 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		probability for most-probable motion candidate
 *		four fields for four quadrants of luminance component
 *		two fields for two chrominance components
 * -----------------------------------------------------------------------------
 */
int pixelQuads_decodeFrameYUV(const CodingOption* pOption, const short** pSideInfoFrame, const uchar** pAccumSyndrome, const short* pScaledQArray, const float* pLowerRateBound, const float** pLaplacian, const char* pLadderFile, const short** pOracleShiftsX, const short** pOracleShiftsY, short** pDecodedFrame, float* pRate, short** pDecodedShiftsX, short** pDecodedShiftsY, float** pDecodedShiftProb);

/* -----------------------------------------------------------------------------
 * pixelQuads_decodeImage
 * -----------------------------------------------------------------------------
 * Decodes four LDPC parity streams, one for each quadrant of an image, into
 * a reconstructed image.
 *
 * Inputs:
 * const CodingOption* pOption
 *		structure containing coding options
 * const short* pImgY
 *		grayscale side information image [[ HEIGHT x WIDTH ]]
 * const unsigned char* pAccumSyndromeQuads[4]
 *		LDPC parity streams [[ BITS_QUAD ]]
 *		four streams for four quadrants of image
 * const short* pScaledQArray
 *		table for quantization of DCT coefficients [[ NUM_COEFFS ]]
 * const float fRateLowerBoundQuads[4]
 *		initial rates at which to start decoding
 *		four rate values for four quadrants of image
 *		bits-per-original-bit
 * const float* pLaplacianQuads[4]
 *		Laplacian parameter sets [[ NUM_COEFFS ]]
 *		four sets for four quadrants of image
 * const char* pLadderFile
 *		name of ladder file
 * const short* pOracleShiftsXQuads
 * const short* pOracleShiftsYQuads
 *		blockwise oracle motion fields 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		four fields for four quadrants of image
 *		used only for motion oracle mode
 *
 * Outputs:
 * short* pDecodedImg
 *		decoded image, same dimensions as side information image
 * float pRate[4]
 *		final rates required for successful decoding
 *		four rate values for four quadrants of image
 *		bits-per-original-bit
 * short* pDecodedShiftsX[4]
 * short* pDecodedShiftsY[4]
 *		decoded blockwise motion fields 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		most-probable motion candidate chosen
 *		four fields for four quadrants of image
 * float* pDecodedShiftProb[4]
 *		decoded blockwise max probabilities 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		probability for most-probable motion candidate
 *		four fields for four quadrants of image
 * -----------------------------------------------------------------------------
 */
int pixelQuads_decodeImage(const CodingOption* pOption, const short* pImgY, const uchar** pAccumSyndrome, const short* pScaledQArray, const float* pLowerRateBound, const float** pLaplacian, const char* pLadderFile, const short** pOracleShiftsX, const short** pOracleShiftsY, short* pDecodedImg, float* pRate, short** pDecodedShiftsX, short** pDecodedShiftsY, float** pDecodedShiftProb);

/* -----------------------------------------------------------------------------
 * pixelQuads_decodeImageQuad
 * -----------------------------------------------------------------------------
 * Decodes an image X given the LDPC bitstream and the side info image Y.
 * Uses space-invariant noise model and blockwise disparity field.
 *
 * Inputs:
 * const CodingOption* pOption
 *		structure containing coding options
 * const short* pImgY
 *		side information image [[ HEIGHT_QUAD x WIDTH_QUAD ]]
 * const unsigned char* pAccumSyndrome
 *		LDPC parity stream [[ BITS_QUAD ]]
 * const short* pScaledQArray
 *		table for quantization of DCT coefficients [[ NUM_COEFFS ]]
 * const float fRateLowerBound
 *		initial rate at which to start decoding
 *		bits-per-original-bit
 * const float* pLaplacian
 *		Laplacian parameter set [[ NUM_COEFFS ]]
 * const char* pLadderFile
 *		name of ladder file
 * const short* pOracleShiftsX
 * const short* pOracleShiftsY
 *		blockwise oracle motion field 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		used only for motion oracle mode
 *
 * Outputs:
 * short* pDecodedImg
 *		decoded image, same dimensions as side information image
 * float* pRate
 *		final rate required for successful decoding
 *		bits-per-original-bit
 * short* pDecodedShiftsX
 * short* pDecodedShiftsY
 *		decoded blockwise motion field 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		most-probable motion candidate chosen
 * float* pDecodedShiftProb
 *		decoded blockwise max probabilities 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD ]]
 *		probability for most-probable motion candidate
 * -----------------------------------------------------------------------------
 */
int pixelQuads_decodeImageQuad(const CodingOption* pOption, const short* pImgY, const uchar* pAccumSyndrome, const short* pScaledQArray, const float fLowerRateBound, const float* pLaplacian, const char* pLadderFile, const short* pOracleShiftsX, const short* pOracleShiftsY, short* pDecodedImg, float* pRate, short* pDecodedShiftsX, short* pDecodedShiftsY, float* pDecodedShiftsProb);

/* -----------------------------------------------------------------------------
 * pixelQuads_pixelDecoderQuad
 * -----------------------------------------------------------------------------
 * Uses values of side information to influence beliefs in bit nodes.
 *
 * Inputs:
 * const int nCodeLength
 *		length of LDPC code
 * const short* pSideInfo
 *		side information array 
 *		[[ NUM_SHIFTS_2D x HEIGHT_QUAD x WIDTH_QUAD ]]
 * const double* pChannel
 *		Laplacian noise channel [[ NUM_COEFFS x LEVELS ]]
 *		NUM_COEFFS channels for NUM_COEFFS subbands
 * const double* pMotionBlock
 *		blockwise motion probabilities 
 *		[[ BLOCK_ROWS_QUAD x BLOCK_COLS_QUAD x NUM_SHIFTS_2D ]]
 * const short* pQuantRange
 *		dynamic ranges of DCT subbands [[ NUM_COEFFS ]]
 * const double* pLLROutput
 *		log-likelihood ratio for decoded bits
 *
 * Outputs:
 * double* pLLRSideInfo
 *		log-likelihood ratio for side information [[ BITS_QUAD ]]
 * double* pProbArray
 *		quantized transform coefficiet probabilities [[ LEVELS ]]
 * -----------------------------------------------------------------------------
 */
int pixelQuads_pixelDecoderQuad(const int nCodeLength, const short* pSideInfo, const double* pChannel, const double* pMotionBlock, const short* pQuantizedCoeffRange, const double* pLLROutput, double* pLLRSideInfo, double* pProbArray);

/* -----------------------------------------------------------------------------
 * pixelQuads_ldpcDecoderQuad
 * -----------------------------------------------------------------------------
 * Exchanges info between bit nodes linked by edges in LDPC graph.
 *
 * Inputs:
 * const int* pIR
 *		sparse matrix index storage buffer
 * const int* pJC
 *		sparse matrix index storage buffer
 * const int nSubcodeLength
 *		length of subsegment of LDPC code
 * const int nCodeLength
 *		length of LDPC code
 * const int nCodeEdges
 *		number of edges in decoding graph
 * const double* pSyndrome