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; **********
; *
; * File Name: omxVCM4P2_PredictReconCoefIntra_s.s
; * OpenMAX DL: v1.0.2
; * Revision: 9641
; * Date: Thursday, February 7, 2008
; *
; * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
; *
; *
; *
; * Description:
; * Contains module for DC/AC coefficient prediction
; *
; *
; * Function: omxVCM4P2_PredictReconCoefIntra
; *
; * Description:
; * Performs adaptive DC/AC coefficient prediction for an intra block. Prior
; * to the function call, prediction direction (predDir) should be selected
; * as specified in subclause 7.4.3.1 of ISO/IEC 14496-2.
; *
; * Remarks:
; *
; * Parameters:
; * [in] pSrcDst pointer to the coefficient buffer which contains the
; * quantized coefficient residuals (PQF) of the current
; * block; must be aligned on a 4-byte boundary. The
; * output coefficients are saturated to the range
; * [-2048, 2047].
; * [in] pPredBufRow pointer to the coefficient row buffer; must be aligned
; * on a 4-byte boundary.
; * [in] pPredBufCol pointer to the coefficient column buffer; must be
; * aligned on a 4-byte boundary.
; * [in] curQP quantization parameter of the current block. curQP may
; * equal to predQP especially when the current block and
; * the predictor block are in the same macroblock.
; * [in] predQP quantization parameter of the predictor block
; * [in] predDir indicates the prediction direction which takes one
; * of the following values:
; * OMX_VIDEO_HORIZONTAL predict horizontally
; * OMX_VIDEO_VERTICAL predict vertically
; * [in] ACPredFlag a flag indicating if AC prediction should be
; * performed. It is equal to ac_pred_flag in the bit
; * stream syntax of MPEG-4
; * [in] videoComp video component type (luminance, chrominance or
; * alpha) of the current block
; * [out] pSrcDst pointer to the coefficient buffer which contains
; * the quantized coefficients (QF) of the current
; * block
; * [out] pPredBufRow pointer to the updated coefficient row buffer
; * [out] pPredBufCol pointer to the updated coefficient column buffer
; * Return Value:
; * OMX_Sts_NoErr - no error
; * OMX_Sts_BadArgErr - Bad arguments
; * - At least one of the pointers is NULL: pSrcDst, pPredBufRow, or pPredBufCol.
; * - At least one the following cases: curQP <= 0, predQP <= 0, curQP >31,
; * predQP > 31, preDir exceeds [1,2].
; * - At least one of the pointers pSrcDst, pPredBufRow, or pPredBufCol is not
; * 4-byte aligned.
; *
; *********
INCLUDE omxtypes_s.h
INCLUDE armCOMM_s.h
M_VARIANTS ARM1136JS
IMPORT armVCM4P2_Reciprocal_QP_S32
IMPORT armVCM4P2_Reciprocal_QP_S16
IMPORT armVCM4P2_DCScaler
IF ARM1136JS
;// Input Arguments
pSrcDst RN 0
pPredBufRow RN 1
pPredBufCol RN 2
curQP RN 3
QP RN 3
predQP RN 4
predDir RN 5
ACPredFlag RN 6
videoComp RN 7
;// Local Variables
temp2 RN 5
negCurQP RN 7
negdcScaler RN 7
tempPred RN 8
dcScaler RN 4
CoeffTable RN 9
absCoeffDC RN 9
temp3 RN 6
absCoeffAC RN 6
shortVideoHeader RN 9
predCoeffTable RN 10
Count RN 10
temp1 RN 12
index RN 12
Rem RN 14
temp RN 11
Return RN 0
M_START omxVCM4P2_PredictReconCoefIntra,r12
;// Assigning pointers to Input arguments on Stack
M_ARG predQPonStack,4
M_ARG predDironStack,4
M_ARG ACPredFlagonStack,4
M_ARG videoComponStack,4
;// DC Prediction
M_LDR videoComp,videoComponStack ;// Load videoComp From Stack
M_LDR predDir,predDironStack ;// Load Prediction direction
;// dcScaler Calculation
LDR index, =armVCM4P2_DCScaler
ADD index,index,videoComp,LSL #5
LDRB dcScaler,[index,QP]
calDCVal
LDR predCoeffTable, =armVCM4P2_Reciprocal_QP_S16 ;// Loading the table with entries 32767/(1 to 63)
CMP predDir,#2 ;// Check if the Prediction direction is vertical
;// Caulucate temp pred by performing Division
LDREQSH absCoeffDC,[pPredBufRow] ;// If vetical load the coeff from Row Prediction Buffer
LDRNESH absCoeffDC,[pPredBufCol] ;// If horizontal load the coeff from column Prediction Buffer
RSB negdcScaler,dcScaler,#0 ;// negdcScaler=-dcScaler
MOV temp1,absCoeffDC ;// temp1=prediction coeff
CMP temp1,#0
RSBLT absCoeffDC,temp1,#0 ;//absCoeffDC=abs(temp1)
ADD temp,dcScaler,dcScaler
LDRH temp,[predCoeffTable,temp] ;// Load value from coeff table for performing division using multiplication
SMULBB tempPred,temp,absCoeffDC ;// tempPred=pPredBufRow(Col)[0]*32767/dcScaler
ADD temp3,dcScaler,#1
LSR tempPred,tempPred,#15 ;// tempPred=pPredBufRow(Col)[0]/dcScaler
LSR temp3,temp3,#1 ;// temp3=round(dcScaler/2)
MLA Rem,negdcScaler,tempPred,absCoeffDC ;// Rem = pPredBufRow(Col)[0]-tempPred*dcScaler
LDRH temp,[pPredBufCol]
CMP Rem,temp3
ADDGE tempPred,#1 ;// If Rem>=round(dcScaler/2);tempPred=tempPred+1
CMP temp1,#0
RSBLT tempPred,tempPred,#0 ;/ if pPredBufRow(Col)[0]<0; tempPred=-tempPred
STRH temp,[pPredBufRow,#-16]
LDRH temp,[pSrcDst] ;// temp=pSrcDst[0]
M_LDR ACPredFlag,ACPredFlagonStack
ADD temp,temp,tempPred ;// temp=pSrcDst[0]+tempPred
SSAT16 temp,#12,temp ;// clip temp to [-2048,2047]
SMULBB temp1,temp,dcScaler ;// temp1=clipped(pSrcDst[0])*dcScaler
M_LDR predQP,predQPonStack
STRH temp,[pSrcDst]
CMP ACPredFlag,#1 ;// Check if the AC prediction flag is set or not
STRH temp1,[pPredBufCol] ;// store temp1 to pPredBufCol
;// AC Prediction
BNE Exit ;// If not set Exit
LDR predCoeffTable, =armVCM4P2_Reciprocal_QP_S32 ;// Loading the table with entries 0x1ffff/(1 to 63)
MOV temp1,#4
MUL temp1,curQP,temp1
CMP predDir,#2 ;// Check the Prediction direction
RSB negCurQP,curQP,#0
LDR CoeffTable,[predCoeffTable,temp1] ;// CoeffTable=0x1ffff/curQP
ADD curQP,curQP,#1 ;// curQP=curQP+1
LSR curQP,curQP,#1 ;// curQP=round(curQP/2)
MOV Count,#2 ;// Initializing the Loop Count
BNE Horizontal ;// If the Prediction direction is horizontal branch to Horizontal
loop1
;// Calculate tempPred
LDRSH absCoeffAC,[pPredBufRow,Count] ;// absCoeffAC=pPredBufRow[i], 1=<i<=7
MOV temp1,absCoeffAC
CMP temp1,#0 ;// compare pPredBufRow[i] with zero, 1=<i<=7
RSBLT absCoeffAC,temp1,#0 ;// absCoeffAC= abs(pPredBufRow[i])
SMULBB absCoeffAC,absCoeffAC,predQP ;// temp1=pPredBufRow[i]*predQP
MUL tempPred,absCoeffAC,CoeffTable ;// tempPred=pPredBufRow[i]*predQP*0x1ffff/curQP
LSR tempPred,tempPred,#17
MLA Rem,negCurQP,tempPred,absCoeffAC ;// Rem=abs(pPredBufRow[i])-tempPred*curQP
LDRH temp,[pSrcDst,Count] ;// temp=pSrcDst[i],1<=i<8
CMP Rem,curQP
ADDGE tempPred,#1 ;// if Rem>=round(curQP/2); tempPred=tempPred+1
CMP temp1,#0
RSBLT tempPred,tempPred,#0 ;// if pPredBufRow[i]<0 ; tempPred=-tempPred
;// Update source and Row Prediction buffers
ADD temp,temp,tempPred ;// temp=tempPred+pSrcDst[i]
SSAT16 temp,#12,temp ;// Clip temp to [-2048,2047]
STRH temp,[pSrcDst,Count]
STRH temp,[pPredBufRow,Count] ;// pPredBufRow[i]=temp
ADD Count,Count,#2 ;// i=i+1
CMP Count,#16 ;// compare if i=8
BLT loop1
B Exit ;// Branch to exit
Horizontal
MOV Count,#16 ;// Initializing i=8
loop2
LSR temp2,Count,#3 ;// temp2=i>>3
;// Calculate tempPred
LDRH absCoeffAC,[pPredBufCol,temp2] ;// absCoefAC=pPredBufCol[i>>3]
MOV temp1,absCoeffAC
CMP temp1,#0 ;// compare pPredBufRow[i] with zero, 1=<i<=7
RSBLT absCoeffAC,temp1,#0 ;// absCoeffAC=abs(pPredBufCol[i>>3])
SMULBB absCoeffAC,absCoeffAC,predQP ;// temp1=pPredBufCol[i>>3]*predQP
MUL tempPred,absCoeffAC,CoeffTable ;// tempPred=pPredBufCol[i>>3]*predQP*0x1ffff/curQP
LSR tempPred,tempPred,#17 ;// tempPred=pPredBufCol[i>>3]*predQP/curQP
MLA Rem,negCurQP,tempPred,absCoeffAC
LDRH temp,[pSrcDst,Count] ;// temp=pSrcDst[i]
CMP Rem,curQP ;// Compare Rem with round(curQP/2)
ADDGE tempPred,#1 ;// tempPred=tempPred+1 if Rem>=round(curQP/2)
CMP temp1,#0
RSBLT tempPred,tempPred,#0 ;// if pPredBufCol[i>>3 <0 tempPred=-tempPred
;// Update source and Row Prediction buffers
ADD temp,temp,tempPred ;// temp=pSrcDst[i]+tempPred
SSAT16 temp,#12,temp ;// Clip temp to [-2048,2047]
STRH temp,[pSrcDst,Count] ;// pSrcDst[0]= clipped value
STRH temp,[pPredBufCol,temp2] ;// pPredBufCol[i>>3]=temp
ADD Count,Count,#16 ;// i=i+8
CMP Count,#128 ;// compare i with 64
BLT loop2
Exit
MOV Return,#OMX_Sts_NoErr
M_END
ENDIF
END
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