omxVCM4P2_DecodeVLCZigzag_IntraACVLC_s.s revision 78e52bfac041d71ce53b5b13c2abf78af742b09d 
1;//
2;// Copyright (C) 2007-2008 ARM Limited
3;//
4;// Licensed under the Apache License, Version 2.0 (the "License");
5;// you may not use this file except in compliance with the License.
6;// You may obtain a copy of the License at
7;//
8;//      http://www.apache.org/licenses/LICENSE-2.0
9;//
10;// Unless required by applicable law or agreed to in writing, software
11;// distributed under the License is distributed on an "AS IS" BASIS,
12;// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13;// See the License for the specific language governing permissions and
14;// limitations under the License.
15;//
16;/**
17; *
18; * File Name:  omxVCM4P2_DecodeVLCZigzag_IntraACVLC_s.s
19; * OpenMAX DL: v1.0.2
20; * Revision:   9641
21; * Date:       Thursday, February 7, 2008
22; *
23; *
24; *
25; *
26; * Description:
27; * Contains modules for zigzag scanning and VLC decoding
28; * for inter block.
29; *
30; *
31; *
32; * Function: omxVCM4P2_DecodeVLCZigzag_Inter
33; *
34; * Description:
35; * Performs VLC decoding and inverse zigzag scan for one intra coded block.
36; *
37; * Remarks:
38; *
39; * Parameters:
40; * [in]    ppBitStream        pointer to the pointer to the current byte in
41; *                    the bitstream buffer
42; * [in]    pBitOffset        pointer to the bit position in the byte pointed
43; *                    to by *ppBitStream. *pBitOffset is valid within    [0-7].
44; * [in] shortVideoHeader     binary flag indicating presence of short_video_header;
45; *                           escape modes 0-3 are used if shortVideoHeader==0,
46; *                           and escape mode 4 is used when shortVideoHeader==1.
47; * [out]    ppBitStream        *ppBitStream is updated after the block is
48; *                    decoded, so that it points to the current byte
49; *                    in the bit stream buffer
50; * [out]    pBitOffset        *pBitOffset is updated so that it points to the
51; *                    current bit position in the byte pointed by
52; *                    *ppBitStream
53; * [out]    pDst            pointer to the coefficient buffer of current
54; *                    block. Must be 16-byte aligned
55; *
56; * Return Value:
57; * OMX_Sts_BadArgErr - bad arguments
58; *   -At least one of the following pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, pDst, or
59; *   -pDst is not 16-byte aligned, or
60; *   -*pBitOffset exceeds [0,7].
61; * OMX_Sts_Err - status error
62; *   -At least one mark bit is equal to zero
63; *   -Encountered an illegal stream code that cannot be found in the VLC table
64; *   -Encountered and illegal code in the VLC FLC table
65; *   -The number of coefficients is greater than 64
66; *
67; */
68
69
70      INCLUDE omxtypes_s.h
71      INCLUDE armCOMM_s.h
72      INCLUDE armCOMM_BitDec_s.h
73
74
75      M_VARIANTS ARM1136JS
76
77
78
79
80
81     IF ARM1136JS
82
83        ;// Import various tables needed for the function
84
85
86        IMPORT          armVCM4P2_IntraVlcL0L1             ;// Contains optimized and packed VLC Tables for both Last =1 and last=0
87                                                               ;// Packed in Run:Level:Last format
88        IMPORT          armVCM4P2_IntraL0L1LMAX            ;// Contains LMAX table entries with both Last=0 and Last=1
89        IMPORT          armVCM4P2_IntraL0L1RMAX            ;// Contains RMAX table entries with both Last=0 and Last=1
90        IMPORT          armVCM4P2_aClassicalZigzagScan     ;// contains classical Zigzag table entries with double the original values
91        IMPORT          armVCM4P2_DecodeVLCZigzag_AC_unsafe
92
93;//Input Arguments
94
95ppBitStream          RN 0
96pBitOffset           RN 1
97pDst                 RN 2
98PredDir              RN 3
99shortVideoHeader     RN 3
100
101;//Local Variables
102
103Return               RN 0
104
105pVlcTableL0L1        RN 4
106pLMAXTableL0L1       RN 4
107pRMAXTableL0L1       RN 4
108pZigzagTable         RN 4
109Count                RN 6
110
111
112
113        ;// Allocate stack memory to store optimized VLC,Zigzag, RMAX, LMAX Table Addresses
114
115        M_ALLOC4        ppVlcTableL0L1,4
116        M_ALLOC4        ppLMAXTableL0L1,4
117        M_ALLOC4        ppRMAXTableL0L1,4
118        M_ALLOC4        ppZigzagTable,4
119
120
121        M_START omxVCM4P2_DecodeVLCZigzag_IntraACVLC,r12
122
123        M_ARG           shortVideoHeaderonStack,4                             ;// pointer to Input Argument on stack
124
125        LDR             pZigzagTable, =armVCM4P2_aClassicalZigzagScan     ;// Load Address of the Zigzag table
126        ADD             pZigzagTable, pZigzagTable, PredDir, LSL #6           ;// Loading Different type of zigzag tables based on PredDir
127
128        M_STR           pZigzagTable,ppZigzagTable                            ;// Store Zigzag table address on stack
129        LDR             pVlcTableL0L1, =armVCM4P2_IntraVlcL0L1            ;// Load optimized packed VLC Table with both L=0 and L=1 entries
130        M_STR           pVlcTableL0L1,ppVlcTableL0L1                          ;// Store VLC Table address on stack
131        LDR             pLMAXTableL0L1, =armVCM4P2_IntraL0L1LMAX          ;// Load LMAX Table
132        M_STR           pLMAXTableL0L1,ppLMAXTableL0L1                        ;// Store LMAX Table address on Stack
133        LDR             pRMAXTableL0L1, =armVCM4P2_IntraL0L1RMAX          ;// Load RMAX Table
134        MOV             Count,#0                                              ;// Set Start=0
135
136        M_STR           pRMAXTableL0L1,ppRMAXTableL0L1                        ;// Store RMAX Table address on stack
137
138
139
140        M_LDR           shortVideoHeader,shortVideoHeaderonStack              ;// get the Input Argument from stack
141
142        BL              armVCM4P2_DecodeVLCZigzag_AC_unsafe               ;// Call Unsafe Function
143
144
145
146
147        M_END
148        ENDIF
149
150        END
151