;//
;// Copyright (C) 2007-2008 ARM Limited
;//
;// Licensed under the Apache License, Version 2.0 (the "License");
;// you may not use this file except in compliance with the License.
;// You may obtain a copy of the License at
;//
;//      http://www.apache.org/licenses/LICENSE-2.0
;//
;// Unless required by applicable law or agreed to in writing, software
;// distributed under the License is distributed on an "AS IS" BASIS,
;// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
;// See the License for the specific language governing permissions and
;// limitations under the License.
;//
;/**
; * 
; * File Name:  omxVCM4P2_DecodeVLCZigzag_IntraACVLC_s.s
; * OpenMAX DL: v1.0.2
; * Revision:   9641
; * Date:       Thursday, February 7, 2008
; * 
; * 
; * 
; *
; * Description: 
; * Contains modules for zigzag scanning and VLC decoding
; * for inter block.
; *
; *
; *
; * Function: omxVCM4P2_DecodeVLCZigzag_Inter
; *
; * Description:
; * Performs VLC decoding and inverse zigzag scan for one intra coded block.
; *
; * Remarks:
; *
; * Parameters:
; * [in]    ppBitStream        pointer to the pointer to the current byte in
; *                    the bitstream buffer
; * [in]    pBitOffset        pointer to the bit position in the byte pointed
; *                    to by *ppBitStream. *pBitOffset is valid within    [0-7].
; * [in] shortVideoHeader     binary flag indicating presence of short_video_header;
; *                           escape modes 0-3 are used if shortVideoHeader==0,
; *                           and escape mode 4 is used when shortVideoHeader==1.
; * [out]    ppBitStream        *ppBitStream is updated after the block is
; *                    decoded, so that it points to the current byte
; *                    in the bit stream buffer
; * [out]    pBitOffset        *pBitOffset is updated so that it points to the
; *                    current bit position in the byte pointed by
; *                    *ppBitStream
; * [out]    pDst            pointer to the coefficient buffer of current
; *                    block. Must be 16-byte aligned
; *
; * Return Value:
; * OMX_Sts_BadArgErr - bad arguments
; *   -At least one of the following pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, pDst, or
; *   -pDst is not 16-byte aligned, or
; *   -*pBitOffset exceeds [0,7].
; * OMX_Sts_Err - status error
; *   -At least one mark bit is equal to zero
; *   -Encountered an illegal stream code that cannot be found in the VLC table
; *   -Encountered and illegal code in the VLC FLC table
; *   -The number of coefficients is greater than 64
; *
; */


      INCLUDE omxtypes_s.h
      INCLUDE armCOMM_s.h
      INCLUDE armCOMM_BitDec_s.h


      M_VARIANTS ARM1136JS

     
     IF ARM1136JS
     
        ;// Import various tables needed for the function

        
        IMPORT          armVCM4P2_IntraVlcL0L1             ;// Contains optimized and packed VLC Tables for both Last =1 and last=0
                                                               ;// Packed in Run:Level:Last format
        IMPORT          armVCM4P2_IntraL0L1LMAX            ;// Contains LMAX table entries with both Last=0 and Last=1
        IMPORT          armVCM4P2_IntraL0L1RMAX            ;// Contains RMAX table entries with both Last=0 and Last=1
        IMPORT          armVCM4P2_aClassicalZigzagScan     ;// contains classical Zigzag table entries with double the original values
        IMPORT          armVCM4P2_DecodeVLCZigzag_AC_unsafe

;//Input Arguments

ppBitStream          RN 0
pBitOffset           RN 1
pDst                 RN 2
PredDir              RN 3
shortVideoHeader     RN 3

;//Local Variables

Return               RN 0

pVlcTableL0L1        RN 4
pLMAXTableL0L1       RN 4
pRMAXTableL0L1       RN 4
pZigzagTable         RN 4
Count                RN 6


        ;// Allocate stack memory to store optimized VLC,Zigzag, RMAX, LMAX Table Addresses 
     
        M_ALLOC4        ppVlcTableL0L1,4
        M_ALLOC4        ppLMAXTableL0L1,4
        M_ALLOC4        ppRMAXTableL0L1,4
        M_ALLOC4        ppZigzagTable,4

        
        M_START omxVCM4P2_DecodeVLCZigzag_IntraACVLC,r12

        M_ARG           shortVideoHeaderonStack,4                             ;// pointer to Input Argument on stack           

        LDR             pZigzagTable, =armVCM4P2_aClassicalZigzagScan     ;// Load Address of the Zigzag table    
        ADD             pZigzagTable, pZigzagTable, PredDir, LSL #6           ;// Loading Different type of zigzag tables based on PredDir
       
        M_STR           pZigzagTable,ppZigzagTable                            ;// Store Zigzag table address on stack
        LDR             pVlcTableL0L1, =armVCM4P2_IntraVlcL0L1            ;// Load optimized packed VLC Table with both L=0 and L=1 entries
        M_STR           pVlcTableL0L1,ppVlcTableL0L1                          ;// Store VLC Table address on stack
        LDR             pLMAXTableL0L1, =armVCM4P2_IntraL0L1LMAX          ;// Load LMAX Table
        M_STR           pLMAXTableL0L1,ppLMAXTableL0L1                        ;// Store LMAX Table address on Stack
        LDR             pRMAXTableL0L1, =armVCM4P2_IntraL0L1RMAX          ;// Load RMAX Table
        MOV             Count,#0                                              ;// Set Start=0        
        
        M_STR           pRMAXTableL0L1,ppRMAXTableL0L1                        ;// Store RMAX Table address on stack
              

        M_LDR           shortVideoHeader,shortVideoHeaderonStack              ;// get the Input Argument from stack

        BL              armVCM4P2_DecodeVLCZigzag_AC_unsafe               ;// Call Unsafe Function


        M_END
        ENDIF
        
        END