1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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.
*/
#include "M4OSA_Types.h"
#include "M4OSA_Debug.h"
#include "M4VD_Tools.h"
/**
************************************************************************
* @file M4VD_Tools.c
* @brief
* @note This file implements helper functions for Bitstream parser
************************************************************************
*/
M4OSA_UInt32 M4VD_Tools_GetBitsFromMemory(M4VS_Bitstream_ctxt* parsingCtxt,
M4OSA_UInt32 nb_bits)
{
M4OSA_UInt32 code;
M4OSA_UInt32 i;
code = 0;
for (i = 0; i < nb_bits; i++)
{
if (parsingCtxt->stream_index == 8)
{
//M4OSA_memcpy( (M4OSA_MemAddr8)&(parsingCtxt->stream_byte), parsingCtxt->in,
// sizeof(unsigned char));
parsingCtxt->stream_byte = (unsigned char)(parsingCtxt->in)[0];
parsingCtxt->in++;
//fread(&stream_byte, sizeof(unsigned char),1,in);
parsingCtxt->stream_index = 0;
}
code = (code << 1);
code |= ((parsingCtxt->stream_byte & 0x80) >> 7);
parsingCtxt->stream_byte = (parsingCtxt->stream_byte << 1);
parsingCtxt->stream_index++;
}
return code;
}
M4OSA_ERR M4VD_Tools_WriteBitsToMemory(M4OSA_UInt32 bitsToWrite,
M4OSA_MemAddr32 dest_bits,
M4OSA_UInt8 offset, M4OSA_UInt8 nb_bits)
{
M4OSA_UInt8 i,j;
M4OSA_UInt32 temp_dest = 0, mask = 0, temp = 1;
M4OSA_UInt32 input = bitsToWrite;
input = (input << (32 - nb_bits - offset));
/* Put destination buffer to 0 */
for(j=0;j<3;j++)
{
for(i=0;i<8;i++)
{
if((j*8)+i >= offset && (j*8)+i < nb_bits + offset)
{
mask |= (temp << ((7*(j+1))-i+j));
}
}
}
mask = ~mask;
*dest_bits &= mask;
/* Parse input bits, and fill output buffer */
for(j=0;j<3;j++)
{
for(i=0;i<8;i++)
{
if((j*8)+i >= offset && (j*8)+i < nb_bits + offset)
{
temp = ((input & (0x80000000 >> offset)) >> (31-offset));
//*dest_bits |= (temp << (31 - i));
*dest_bits |= (temp << ((7*(j+1))-i+j));
input = (input << 1);
}
}
}
return M4NO_ERROR;
}
|
