mirror of
https://github.com/HDFGroup/hdf5.git
synced 2024-12-21 07:51:46 +08:00
11dfa25910
* Updated source file copyright headers to remove "Copyright by the Board of Trustees of the University of Illinois", which is kept in the top-level COPYING file.
121 lines
3.9 KiB
C
121 lines
3.9 KiB
C
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
|
|
* Copyright by The HDF Group. *
|
|
* All rights reserved. *
|
|
* *
|
|
* This file is part of HDF5. The full HDF5 copyright notice, including *
|
|
* terms governing use, modification, and redistribution, is contained in *
|
|
* the COPYING file, which can be found at the root of the source code *
|
|
* distribution tree, or in https://www.hdfgroup.org/licenses. *
|
|
* If you do not have access to either file, you may request a copy from *
|
|
* help@hdfgroup.org. *
|
|
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
|
|
|
|
/*
|
|
* This example illustrates how to create a compressed dataset.
|
|
* It is used in the HDF5 Tutorial.
|
|
*/
|
|
|
|
#include "hdf5.h"
|
|
|
|
#define FILE "cmprss.h5"
|
|
#define RANK 2
|
|
#define DIM0 100
|
|
#define DIM1 20
|
|
|
|
int
|
|
main()
|
|
{
|
|
|
|
hid_t file_id, dataset_id, dataspace_id; /* identifiers */
|
|
hid_t plist_id;
|
|
|
|
size_t nelmts;
|
|
unsigned flags, filter_info;
|
|
H5Z_filter_t filter_type;
|
|
|
|
herr_t status;
|
|
hsize_t dims[2];
|
|
hsize_t cdims[2];
|
|
|
|
int i, j, numfilt;
|
|
int buf[DIM0][DIM1];
|
|
int rbuf[DIM0][DIM1];
|
|
|
|
/* Uncomment these variables to use SZIP compression
|
|
unsigned szip_options_mask;
|
|
unsigned szip_pixels_per_block;
|
|
*/
|
|
|
|
/* Create a file. */
|
|
file_id = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
|
|
|
|
/* Create dataset "Compressed Data" in the group using absolute name. */
|
|
dims[0] = DIM0;
|
|
dims[1] = DIM1;
|
|
dataspace_id = H5Screate_simple(RANK, dims, NULL);
|
|
|
|
plist_id = H5Pcreate(H5P_DATASET_CREATE);
|
|
|
|
/* Dataset must be chunked for compression */
|
|
cdims[0] = 20;
|
|
cdims[1] = 20;
|
|
status = H5Pset_chunk(plist_id, 2, cdims);
|
|
|
|
/* Set ZLIB / DEFLATE Compression using compression level 6.
|
|
* To use SZIP Compression comment out these lines.
|
|
*/
|
|
status = H5Pset_deflate(plist_id, 6);
|
|
|
|
/* Uncomment these lines to set SZIP Compression
|
|
szip_options_mask = H5_SZIP_NN_OPTION_MASK;
|
|
szip_pixels_per_block = 16;
|
|
status = H5Pset_szip (plist_id, szip_options_mask, szip_pixels_per_block);
|
|
*/
|
|
|
|
dataset_id = H5Dcreate2(file_id, "Compressed_Data", H5T_STD_I32BE, dataspace_id, H5P_DEFAULT, plist_id,
|
|
H5P_DEFAULT);
|
|
|
|
for (i = 0; i < DIM0; i++)
|
|
for (j = 0; j < DIM1; j++)
|
|
buf[i][j] = i + j;
|
|
|
|
status = H5Dwrite(dataset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf);
|
|
|
|
status = H5Sclose(dataspace_id);
|
|
status = H5Dclose(dataset_id);
|
|
status = H5Pclose(plist_id);
|
|
status = H5Fclose(file_id);
|
|
|
|
/* Now reopen the file and dataset in the file. */
|
|
file_id = H5Fopen(FILE, H5F_ACC_RDWR, H5P_DEFAULT);
|
|
dataset_id = H5Dopen2(file_id, "Compressed_Data", H5P_DEFAULT);
|
|
|
|
/* Retrieve filter information. */
|
|
plist_id = H5Dget_create_plist(dataset_id);
|
|
|
|
numfilt = H5Pget_nfilters(plist_id);
|
|
printf("Number of filters associated with dataset: %i\n", numfilt);
|
|
|
|
for (i = 0; i < numfilt; i++) {
|
|
nelmts = 0;
|
|
filter_type = H5Pget_filter2(plist_id, i, &flags, &nelmts, NULL, 0, NULL, &filter_info);
|
|
printf("Filter Type: ");
|
|
switch (filter_type) {
|
|
case H5Z_FILTER_DEFLATE:
|
|
printf("H5Z_FILTER_DEFLATE\n");
|
|
break;
|
|
case H5Z_FILTER_SZIP:
|
|
printf("H5Z_FILTER_SZIP\n");
|
|
break;
|
|
default:
|
|
printf("Other filter type included.\n");
|
|
}
|
|
}
|
|
|
|
status = H5Dread(dataset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, rbuf);
|
|
|
|
status = H5Dclose(dataset_id);
|
|
status = H5Pclose(plist_id);
|
|
status = H5Fclose(file_id);
|
|
}
|