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