/src/gdal/third_party/LercLib/Lerc.h
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1 | | /* |
2 | | Copyright 2015 Esri |
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 | | A local copy of the license and additional notices are located with the |
17 | | source distribution at: |
18 | | |
19 | | http://github.com/Esri/lerc/ |
20 | | |
21 | | Contributors: Thomas Maurer |
22 | | */ |
23 | | |
24 | | #pragma once |
25 | | |
26 | | #include <cstring> |
27 | | #include <vector> |
28 | | #include "Lerc_types.h" |
29 | | #include "BitMask.h" |
30 | | #include "Lerc2.h" |
31 | | |
32 | | NAMESPACE_LERC_START |
33 | | |
34 | | #ifdef HAVE_LERC1_DECODE |
35 | | class CntZImage; |
36 | | #endif |
37 | | |
38 | | class Lerc |
39 | | { |
40 | | public: |
41 | 0 | Lerc() {} |
42 | 0 | ~Lerc() {} |
43 | | |
44 | | // data types supported by Lerc |
45 | | enum DataType { DT_Char, DT_Byte, DT_Short, DT_UShort, DT_Int, DT_UInt, DT_Float, DT_Double, DT_Undefined }; |
46 | | |
47 | | // all functions are provided in 2 flavors |
48 | | // - using void pointers to the image data, can be called on a Lerc lib or dll |
49 | | // - data templated, can be called if compiled together |
50 | | |
51 | | |
52 | | // Encode |
53 | | |
54 | | // if more than 1 band, the outgoing Lerc blob has the single band Lerc blobs concatenated; |
55 | | // or, if you have multiple values per pixel and stored as [RGB, RGB, ... ], then set nDim accordingly (e.g., 3) |
56 | | |
57 | | // computes the number of bytes needed to allocate the buffer, accurate to the byte; |
58 | | // does not encode the image data, but uses statistics and formulas to compute the buffer size needed; |
59 | | // this function is optional, you can also use a buffer large enough to call Encode() directly, |
60 | | // or, if encoding a batch of same width / height tiles, call this function once, double the buffer size, and |
61 | | // then just call Encode() on all tiles; |
62 | | |
63 | | static ErrCode ComputeCompressedSize( |
64 | | const void* pData, // raw image data, row by row, band by band |
65 | | int version, // 2 = v2.2, 3 = v2.3, 4 = v2.4 |
66 | | DataType dt, // data type, char to double |
67 | | int nDim, // number of values per pixel |
68 | | int nCols, // number of cols |
69 | | int nRows, // number of rows |
70 | | int nBands, // number of bands |
71 | | const BitMask* pBitMask, // 0 if all pixels are valid |
72 | | double maxZErr, // max coding error per pixel, defines the precision |
73 | | unsigned int& numBytesNeeded); // size of outgoing Lerc blob |
74 | | |
75 | | // encodes or compresses the image data into the buffer |
76 | | |
77 | | static ErrCode Encode( |
78 | | const void* pData, // raw image data, row by row, band by band |
79 | | int version, // 2 = v2.2, 3 = v2.3, 4 = v2.4 |
80 | | DataType dt, // data type, char to double |
81 | | int nDim, // number of values per pixel |
82 | | int nCols, // number of cols |
83 | | int nRows, // number of rows |
84 | | int nBands, // number of bands |
85 | | const BitMask* pBitMask, // 0 if all pixels are valid |
86 | | double maxZErr, // max coding error per pixel, defines the precision |
87 | | Byte* pBuffer, // buffer to write to, function fails if buffer too small |
88 | | unsigned int numBytesBuffer, // buffer size |
89 | | unsigned int& numBytesWritten); // num bytes written to buffer |
90 | | |
91 | | |
92 | | // Decode |
93 | | |
94 | | struct LercInfo |
95 | | { |
96 | | int version, // Lerc version number (0 for old Lerc1, 1 to 4 for Lerc 2.1 to 2.4) |
97 | | nDim, // number of values per pixel |
98 | | nCols, // number of columns |
99 | | nRows, // number of rows |
100 | | numValidPixel, // number of valid pixels |
101 | | nBands, // number of bands |
102 | | blobSize; // total blob size in bytes |
103 | | DataType dt; // data type (float only for old Lerc1) |
104 | | double zMin, // min pixel value, over all data values |
105 | | zMax, // max pixel value, over all data values |
106 | | maxZError; // maxZError used for encoding |
107 | | |
108 | 360 | void RawInit() { memset(this, 0, sizeof(struct LercInfo)); } |
109 | | }; |
110 | | |
111 | | // again, this function is optional; |
112 | | // call it on a Lerc blob to get the above struct returned, from this the data arrays |
113 | | // can be constructed before calling Decode(); |
114 | | // same as above, for a batch of Lerc blobs of the same kind, you can call this function on |
115 | | // the first blob, get the info, and on the other Lerc blobs just call Decode(); |
116 | | // this function is very fast on (newer) Lerc2 blobs as it only reads the blob headers; |
117 | | |
118 | | // Remark on param numBytesBlob. Usually it is known, either the file size of the blob written to disk, |
119 | | // or the size of the blob transmitted. It should be accurate for 2 reasons: |
120 | | // _ function finds out how many single band Lerc blobs are concatenated |
121 | | // _ function checks for truncated file or blob |
122 | | // It is OK to pass numBytesBlob too large as long as there is no other (valid) Lerc blob following next. |
123 | | // If in doubt, check the code in Lerc::GetLercInfo(...) for the exact logic. |
124 | | |
125 | | static ErrCode GetLercInfo(const Byte* pLercBlob, // Lerc blob to decode |
126 | | unsigned int numBytesBlob, // size of Lerc blob in bytes |
127 | | struct LercInfo& lercInfo); |
128 | | |
129 | | // setup outgoing arrays accordingly, then call Decode() |
130 | | |
131 | | static ErrCode Decode( |
132 | | const Byte* pLercBlob, // Lerc blob to decode |
133 | | unsigned int numBytesBlob, // size of Lerc blob in bytes |
134 | | BitMask* pBitMask, // gets filled if not 0, even if all valid |
135 | | int nDim, // number of values per pixel |
136 | | int nCols, // number of cols |
137 | | int nRows, // number of rows |
138 | | int nBands, // number of bands |
139 | | DataType dt, // data type of outgoing array |
140 | | void* pData); // outgoing data bands |
141 | | |
142 | | |
143 | | static ErrCode ConvertToDouble( |
144 | | const void* pDataIn, // pixel data of image tile of data type dt (< double) |
145 | | DataType dt, // data type of input data |
146 | | size_t nDataValues, // total number of data values (nDim * nCols * nRows * nBands) |
147 | | double* pDataOut); // pixel data converted to double |
148 | | |
149 | | |
150 | | // same as functions above, but data templated instead of using void pointers |
151 | | |
152 | | template<class T> static ErrCode ComputeCompressedSizeTempl( |
153 | | const T* pData, // raw image data, row by row, band by |
154 | | int version, // 2 = v2.2, 3 = v2.3, 4 = v2.4 |
155 | | int nDim, // number of values per pixel |
156 | | int nCols, // number of cols |
157 | | int nRows, // number of rows |
158 | | int nBands, // number of bands |
159 | | const BitMask* pBitMask, // 0 means all pixels are valid |
160 | | double maxZErr, // max coding error per pixel, defines the precision |
161 | | unsigned int& numBytes); // size of outgoing Lerc blob |
162 | | |
163 | | template<class T> static ErrCode EncodeTempl( |
164 | | const T* pData, // raw image data, row by row, band by band |
165 | | int version, // 2 = v2.2, 3 = v2.3, 4 = v2.4 |
166 | | int nDim, // number of values per pixel |
167 | | int nCols, // number of cols |
168 | | int nRows, // number of rows |
169 | | int nBands, // number of bands |
170 | | const BitMask* pBitMask, // 0 means all pixels are valid |
171 | | double maxZErr, // max coding error per pixel, defines the precision |
172 | | Byte* pBuffer, // buffer to write to, function will fail if buffer too small |
173 | | unsigned int numBytesBuffer, // buffer size |
174 | | unsigned int& numBytesWritten); // num bytes written to buffer |
175 | | |
176 | | template<class T> static ErrCode DecodeTempl( |
177 | | T* pData, // outgoing data bands |
178 | | const Byte* pLercBlob, // Lerc blob to decode |
179 | | unsigned int numBytesBlob, // size of Lerc blob in bytes |
180 | | int nDim, // number of values per pixel |
181 | | int nCols, // number of cols |
182 | | int nRows, // number of rows |
183 | | int nBands, // number of bands |
184 | | BitMask* pBitMask); // gets filled if not 0, even if all valid |
185 | | |
186 | | private: |
187 | | #ifdef HAVE_LERC1_DECODE |
188 | | template<class T> static bool Convert(const CntZImage& zImg, T* arr, BitMask* pBitMask); |
189 | | #endif |
190 | | template<class T> static ErrCode ConvertToDoubleTempl(const T* pDataIn, size_t nDataValues, double* pDataOut); |
191 | | |
192 | | template<class T> static ErrCode CheckForNaN(const T* arr, int nDim, int nCols, int nRows, const BitMask* pBitMask); |
193 | | }; |
194 | | NAMESPACE_LERC_END |