1;/** 2; * 3; * File Name: omxVCM4P2_DecodeVLCZigzag_Inter_s.s 4; * OpenMAX DL: v1.0.2 5; * Revision: 12290 6; * Date: Wednesday, April 9, 2008 7; * 8; * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved. 9; * 10; * 11; * 12; * Description: 13; * Contains modules for zigzag scanning and VLC decoding 14; * for inter block. 15; * 16; * 17; * 18; * Function: omxVCM4P2_DecodeVLCZigzag_Inter 19; * 20; * Description: 21; * Performs VLC decoding and inverse zigzag scan for one inter coded block. 22; * 23; * Remarks: 24; * 25; * Parameters: 26; * [in] ppBitStream pointer to the pointer to the current byte in 27; * the bitstream buffer 28; * [in] pBitOffset pointer to the bit position in the byte pointed 29; * to by *ppBitStream. *pBitOffset is valid within [0-7]. 30; * [in] shortVideoHeader binary flag indicating presence of short_video_header; 31; * escape modes 0-3 are used if shortVideoHeader==0, 32; * and escape mode 4 is used when shortVideoHeader==1. 33; * [out] ppBitStream *ppBitStream is updated after the block is 34; * decoded, so that it points to the current byte 35; * in the bit stream buffer 36; * [out] pBitOffset *pBitOffset is updated so that it points to the 37; * current bit position in the byte pointed by 38; * *ppBitStream 39; * [out] pDst pointer to the coefficient buffer of current 40; * block. Must be 16-byte aligned 41; * 42; * Return Value: 43; * OMX_Sts_BadArgErr - bad arguments 44; * -At least one of the following pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, pDst, or 45; * -pDst is not 16-byte aligned, or 46; * -*pBitOffset exceeds [0,7]. 47; * OMX_Sts_Err - status error 48; * -At least one mark bit is equal to zero 49; * -Encountered an illegal stream code that cannot be found in the VLC table 50; * -Encountered and illegal code in the VLC FLC table 51; * -The number of coefficients is greater than 64 52; * 53; */ 54 55 56 INCLUDE omxtypes_s.h 57 INCLUDE armCOMM_s.h 58 INCLUDE armCOMM_BitDec_s.h 59 60 61 M_VARIANTS ARM1136JS 62 63 64 65 66 67 IF ARM1136JS 68 69 ;// Import various tables needed for the function 70 71 72 IMPORT armVCM4P2_InterVlcL0L1 ;// Contains optimized and packed VLC Tables for both Last =1 and last=0 73 ;// Packed in Run:Level:Last format 74 IMPORT armVCM4P2_InterL0L1LMAX ;// Contains LMAX table entries with both Last=0 and Last=1 75 IMPORT armVCM4P2_InterL0L1RMAX ;// Contains RMAX table entries with both Last=0 and Last=1 76 IMPORT armVCM4P2_aClassicalZigzagScan ;// contains classical Zigzag table entries with double the original values 77 IMPORT armVCM4P2_DecodeVLCZigzag_AC_unsafe 78 79 80 81;//Input Arguments 82 83ppBitStream RN 0 84pBitOffset RN 1 85pDst RN 2 86shortVideoHeader RN 3 87 88;//Local Variables 89 90Return RN 0 91 92pVlcTableL0L1 RN 4 93pLMAXTableL0L1 RN 4 94pRMAXTableL0L1 RN 4 95pZigzagTable RN 4 96Count RN 6 97 98 99 100 ;// Allocate stack memory to store the VLC,Zigzag,LMAX and RMAX tables 101 102 103 M_ALLOC4 ppVlcTableL0L1,4 104 M_ALLOC4 ppLMAXTableL0L1,4 105 M_ALLOC4 ppRMAXTableL0L1,4 106 M_ALLOC4 ppZigzagTable,4 107 108 109 M_START omxVCM4P2_DecodeVLCZigzag_Inter,r12 110 111 112 113 114 LDR pZigzagTable, =armVCM4P2_aClassicalZigzagScan ;// Load zigzag table 115 M_STR pZigzagTable,ppZigzagTable ;// Store zigzag table on stack to pass as argument to unsafe function 116 LDR pVlcTableL0L1, =armVCM4P2_InterVlcL0L1 ;// Load optimized VLC table with both L=0 and L=1 entries 117 M_STR pVlcTableL0L1,ppVlcTableL0L1 ;// Store optimized VLC table address on stack 118 LDR pLMAXTableL0L1, =armVCM4P2_InterL0L1LMAX ;// Load Interleaved L=0 and L=1 LMAX Tables 119 M_STR pLMAXTableL0L1,ppLMAXTableL0L1 ;// Store LMAX table address on stack 120 LDR pRMAXTableL0L1, =armVCM4P2_InterL0L1RMAX ;// Load Interleaved L=0 and L=1 RMAX Tables 121 MOV Count,#0 ;// set start=0 122 M_STR pRMAXTableL0L1,ppRMAXTableL0L1 ;// store RMAX table address on stack 123 124 125 BL armVCM4P2_DecodeVLCZigzag_AC_unsafe ;// call Unsafe Function for VLC Zigzag Decoding 126 127 128 129 M_END 130 ENDIF 131 132 END 133