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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
// Copyright 2017 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#include "core/fpdfapi/page/cpdf_sampledfunc.h"
#include "core/fpdfapi/parser/cpdf_array.h"
#include "core/fxcrt/cfx_fixedbufgrow.h"
#include "core/fxcrt/fx_extension.h"
#include "core/fxcrt/fx_safe_types.h"
namespace {
// See PDF Reference 1.7, page 170, table 3.36.
bool IsValidBitsPerSample(uint32_t x) {
switch (x) {
case 1:
case 2:
case 4:
case 8:
case 12:
case 16:
case 24:
case 32:
return true;
default:
return false;
}
}
} // namespace
CPDF_SampledFunc::CPDF_SampledFunc() : CPDF_Function(Type::kType0Sampled) {}
CPDF_SampledFunc::~CPDF_SampledFunc() {}
bool CPDF_SampledFunc::v_Init(CPDF_Object* pObj) {
CPDF_Stream* pStream = pObj->AsStream();
if (!pStream)
return false;
CPDF_Dictionary* pDict = pStream->GetDict();
CPDF_Array* pSize = pDict->GetArrayFor("Size");
CPDF_Array* pEncode = pDict->GetArrayFor("Encode");
CPDF_Array* pDecode = pDict->GetArrayFor("Decode");
m_nBitsPerSample = pDict->GetIntegerFor("BitsPerSample");
if (!IsValidBitsPerSample(m_nBitsPerSample))
return false;
m_SampleMax = 0xffffffff >> (32 - m_nBitsPerSample);
m_pSampleStream = pdfium::MakeRetain<CPDF_StreamAcc>(pStream);
m_pSampleStream->LoadAllDataFiltered();
FX_SAFE_UINT32 nTotalSampleBits = 1;
m_EncodeInfo.resize(m_nInputs);
for (uint32_t i = 0; i < m_nInputs; i++) {
m_EncodeInfo[i].sizes = pSize ? pSize->GetIntegerAt(i) : 0;
if (!pSize && i == 0)
m_EncodeInfo[i].sizes = pDict->GetIntegerFor("Size");
nTotalSampleBits *= m_EncodeInfo[i].sizes;
if (pEncode) {
m_EncodeInfo[i].encode_min = pEncode->GetFloatAt(i * 2);
m_EncodeInfo[i].encode_max = pEncode->GetFloatAt(i * 2 + 1);
} else {
m_EncodeInfo[i].encode_min = 0;
m_EncodeInfo[i].encode_max =
m_EncodeInfo[i].sizes == 1 ? 1 : (float)m_EncodeInfo[i].sizes - 1;
}
}
nTotalSampleBits *= m_nBitsPerSample;
nTotalSampleBits *= m_nOutputs;
FX_SAFE_UINT32 nTotalSampleBytes = nTotalSampleBits;
nTotalSampleBytes += 7;
nTotalSampleBytes /= 8;
if (!nTotalSampleBytes.IsValid() || nTotalSampleBytes.ValueOrDie() == 0 ||
nTotalSampleBytes.ValueOrDie() > m_pSampleStream->GetSize()) {
return false;
}
m_DecodeInfo.resize(m_nOutputs);
for (uint32_t i = 0; i < m_nOutputs; i++) {
if (pDecode) {
m_DecodeInfo[i].decode_min = pDecode->GetFloatAt(2 * i);
m_DecodeInfo[i].decode_max = pDecode->GetFloatAt(2 * i + 1);
} else {
m_DecodeInfo[i].decode_min = m_pRanges[i * 2];
m_DecodeInfo[i].decode_max = m_pRanges[i * 2 + 1];
}
}
return true;
}
bool CPDF_SampledFunc::v_Call(float* inputs, float* results) const {
int pos = 0;
CFX_FixedBufGrow<float, 16> encoded_input_buf(m_nInputs);
float* encoded_input = encoded_input_buf;
CFX_FixedBufGrow<uint32_t, 32> int_buf(m_nInputs * 2);
uint32_t* index = int_buf;
uint32_t* blocksize = index + m_nInputs;
for (uint32_t i = 0; i < m_nInputs; i++) {
if (i == 0)
blocksize[i] = 1;
else
blocksize[i] = blocksize[i - 1] * m_EncodeInfo[i - 1].sizes;
encoded_input[i] =
Interpolate(inputs[i], m_pDomains[i * 2], m_pDomains[i * 2 + 1],
m_EncodeInfo[i].encode_min, m_EncodeInfo[i].encode_max);
index[i] = pdfium::clamp(static_cast<uint32_t>(encoded_input[i]), 0U,
m_EncodeInfo[i].sizes - 1);
pos += index[i] * blocksize[i];
}
FX_SAFE_INT32 bits_to_output = m_nOutputs;
bits_to_output *= m_nBitsPerSample;
if (!bits_to_output.IsValid())
return false;
FX_SAFE_INT32 bitpos = pos;
bitpos *= bits_to_output.ValueOrDie();
if (!bitpos.IsValid())
return false;
FX_SAFE_INT32 range_check = bitpos;
range_check += bits_to_output.ValueOrDie();
if (!range_check.IsValid())
return false;
const uint8_t* pSampleData = m_pSampleStream->GetData();
if (!pSampleData)
return false;
for (uint32_t j = 0; j < m_nOutputs; j++, bitpos += m_nBitsPerSample) {
uint32_t sample =
GetBits32(pSampleData, bitpos.ValueOrDie(), m_nBitsPerSample);
float encoded = (float)sample;
for (uint32_t i = 0; i < m_nInputs; i++) {
if (index[i] == m_EncodeInfo[i].sizes - 1) {
if (index[i] == 0)
encoded = encoded_input[i] * (float)sample;
} else {
FX_SAFE_INT32 bitpos2 = blocksize[i];
bitpos2 += pos;
bitpos2 *= m_nOutputs;
bitpos2 += j;
bitpos2 *= m_nBitsPerSample;
if (!bitpos2.IsValid())
return false;
uint32_t sample1 =
GetBits32(pSampleData, bitpos2.ValueOrDie(), m_nBitsPerSample);
encoded +=
(encoded_input[i] - index[i]) * ((float)sample1 - (float)sample);
}
}
results[j] =
Interpolate(encoded, 0, (float)m_SampleMax, m_DecodeInfo[j].decode_min,
m_DecodeInfo[j].decode_max);
}
return true;
}
|
