1;/**
2; *
3; * File Name:  omxVCM4P2_DecodeVLCZigzag_IntraACVLC_s.s
4; * OpenMAX DL: v1.0.2
5; * Revision:   9641
6; * Date:       Thursday, February 7, 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 intra 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_IntraVlcL0L1             ;// Contains optimized and packed VLC Tables for both Last =1 and last=0
73                                                               ;// Packed in Run:Level:Last format
74        IMPORT          armVCM4P2_IntraL0L1LMAX            ;// Contains LMAX table entries with both Last=0 and Last=1
75        IMPORT          armVCM4P2_IntraL0L1RMAX            ;// 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;//Input Arguments
80
81ppBitStream          RN 0
82pBitOffset           RN 1
83pDst                 RN 2
84PredDir              RN 3
85shortVideoHeader     RN 3
86
87;//Local Variables
88
89Return               RN 0
90
91pVlcTableL0L1        RN 4
92pLMAXTableL0L1       RN 4
93pRMAXTableL0L1       RN 4
94pZigzagTable         RN 4
95Count                RN 6
96
97
98
99        ;// Allocate stack memory to store optimized VLC,Zigzag, RMAX, LMAX Table Addresses
100
101        M_ALLOC4        ppVlcTableL0L1,4
102        M_ALLOC4        ppLMAXTableL0L1,4
103        M_ALLOC4        ppRMAXTableL0L1,4
104        M_ALLOC4        ppZigzagTable,4
105
106
107        M_START omxVCM4P2_DecodeVLCZigzag_IntraACVLC,r12
108
109        M_ARG           shortVideoHeaderonStack,4                             ;// pointer to Input Argument on stack
110
111        LDR             pZigzagTable, =armVCM4P2_aClassicalZigzagScan     ;// Load Address of the Zigzag table
112        ADD             pZigzagTable, pZigzagTable, PredDir, LSL #6           ;// Loading Different type of zigzag tables based on PredDir
113
114        M_STR           pZigzagTable,ppZigzagTable                            ;// Store Zigzag table address on stack
115        LDR             pVlcTableL0L1, =armVCM4P2_IntraVlcL0L1            ;// Load optimized packed VLC Table with both L=0 and L=1 entries
116        M_STR           pVlcTableL0L1,ppVlcTableL0L1                          ;// Store VLC Table address on stack
117        LDR             pLMAXTableL0L1, =armVCM4P2_IntraL0L1LMAX          ;// Load LMAX Table
118        M_STR           pLMAXTableL0L1,ppLMAXTableL0L1                        ;// Store LMAX Table address on Stack
119        LDR             pRMAXTableL0L1, =armVCM4P2_IntraL0L1RMAX          ;// Load RMAX Table
120        MOV             Count,#0                                              ;// Set Start=0
121
122        M_STR           pRMAXTableL0L1,ppRMAXTableL0L1                        ;// Store RMAX Table address on stack
123
124
125
126        M_LDR           shortVideoHeader,shortVideoHeaderonStack              ;// get the Input Argument from stack
127
128        BL              armVCM4P2_DecodeVLCZigzag_AC_unsafe               ;// Call Unsafe Function
129
130
131
132
133        M_END
134        ENDIF
135
136        END
137