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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* All rights reserved. *
* *
* This file is part of the HDF5 JPEG filter plugin source. The full *
* copyright notice, including terms governing use, modification, and *
* terms governing use, modification, and redistribution, is contained in *
* the file COPYING, which can be found at the root of the JPEG source code *
* distribution tree. If you do not have access to this file, you may *
* request a copy from help@hdfgroup.org. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/************************************************************
This example shows how to write data and read it from a dataset
using jpeg compression.
jpeg filter is not available in HDF5.
The example uses a new feature available in HDF5 version 1.8.11
to discover, load and register filters at run time.
************************************************************/
#include "hdf5.h"
#include <stdio.h>
#include <stdlib.h>
#define FILE "h5ex_d_jpeg.h5"
#define DATASET "DS1"
#define DIM0 512
#define DIM1 1024
#define NUM_IMAGES 2
#define JPEG_QUALITY 100
#define CHUNK0 1
#define CHUNK1 DIM0
#define CHUNK2 DIM1
#define H5Z_FILTER_JPEG 32019
int
main(void)
{
hid_t file_id = H5I_INVALID_HID; /* Handles */
hid_t space_id = H5I_INVALID_HID; /* Handles */
hid_t dset_id = H5I_INVALID_HID; /* Handles */
hid_t dcpl_id = H5I_INVALID_HID; /* Handles */
herr_t status;
htri_t avail;
H5Z_filter_t filter_id = 0;
char filter_name[80];
hsize_t dims[3] = {NUM_IMAGES, DIM0, DIM1}, chunk[3] = {CHUNK0, CHUNK1, CHUNK2};
size_t nelmts = 4; /* number of elements in cd_values */
unsigned int flags;
unsigned filter_config;
size_t data_size = DIM0 * DIM1 * NUM_IMAGES;
/* JPEG filter requires 4 parameters */
/* JPEG quality factor (1-100) */
/* Number of columns */
/* Number of rows */
/* Color mode (0=Mono, 1=RGB) */
const unsigned int cd_values[4] = {JPEG_QUALITY, DIM1, DIM0, 0}; /* jpeg default level is 2 */
unsigned int values_out[4] = {99, 99, 99, 99};
unsigned char *wdata, /* Write buffer */
*rdata; /* Read buffer */
int num_diff = 0;
hsize_t i;
int ret_value = 1;
wdata = (unsigned char *)malloc(sizeof(unsigned char) * data_size);
rdata = (unsigned char *)malloc(sizeof(unsigned char) * data_size);
for (i = 0; i < data_size; i++) {
wdata[i] = i;
}
/*
* Create a new file using the default properties.
*/
file_id = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
if (file_id < 0)
goto done;
/*
* Create dataspace. Setting maximum size to NULL sets the maximum
* size to be the current size.
*/
space_id = H5Screate_simple(3, dims, NULL);
if (space_id < 0)
goto done;
/*
* Create the dataset creation property list, add the gzip
* compression filter and set the chunk size.
*/
dcpl_id = H5Pcreate(H5P_DATASET_CREATE);
if (dcpl_id < 0)
goto done;
status = H5Pset_filter(dcpl_id, H5Z_FILTER_JPEG, H5Z_FLAG_MANDATORY, nelmts, cd_values);
if (status < 0)
goto done;
/*
* Check that filter is registered with the library now.
* If it is registered, retrieve filter's configuration.
*/
avail = H5Zfilter_avail(H5Z_FILTER_JPEG);
if (avail) {
status = H5Zget_filter_info(H5Z_FILTER_JPEG, &filter_config);
if ((filter_config & H5Z_FILTER_CONFIG_ENCODE_ENABLED) &&
(filter_config & H5Z_FILTER_CONFIG_DECODE_ENABLED))
fprintf(stdout, "jpeg filter is available for encoding and decoding.\n");
}
else {
fprintf(stdout, "H5Zfilter_avail - not found.\n");
goto done;
}
status = H5Pset_chunk(dcpl_id, 3, chunk);
if (status < 0)
fprintf(stdout, "failed to set chunk.\n");
/*
* Create the dataset.
*/
fprintf(stdout, "....Create dataset ................\n");
dset_id = H5Dcreate(file_id, DATASET, H5T_NATIVE_UINT8, space_id, H5P_DEFAULT, dcpl_id, H5P_DEFAULT);
if (dset_id < 0) {
fprintf(stdout, "failed to create dataset.\n");
goto done;
}
fflush(stdout);
/*
* Write the data to the dataset.
*/
fprintf(stdout, "....Writing jpeg compressed data ................\n");
status = H5Dwrite(dset_id, H5T_NATIVE_UINT8, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata);
if (status < 0)
fprintf(stdout, "failed to write data.\n");
fflush(stdout);
/*
* Close and release resources.
*/
H5Dclose(dset_id);
dset_id = -1;
H5Pclose(dcpl_id);
dcpl_id = -1;
H5Sclose(space_id);
space_id = -1;
H5Fclose(file_id);
file_id = -1;
status = H5close();
if (status < 0) {
fprintf(stdout, "/nFAILED to close library/n");
goto done;
}
fprintf(stdout, "....Close the file and reopen for reading ........\n");
/*
* Now we begin the read section of this example.
*/
/*
* Open file and dataset using the default properties.
*/
file_id = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT);
if (file_id < 0)
goto done;
dset_id = H5Dopen(file_id, DATASET, H5P_DEFAULT);
if (dset_id < 0)
goto done;
/*
* Retrieve dataset creation property list.
*/
dcpl_id = H5Dget_create_plist(dset_id);
if (dcpl_id < 0)
goto done;
/*
* Retrieve and print the filter id, compression level and filter's name for jpeg.
*/
filter_id = H5Pget_filter2(dcpl_id, (unsigned)0, &flags, &nelmts, values_out, sizeof(filter_name),
filter_name, NULL);
fprintf(stdout, "Filter info is available from the dataset creation property \n ");
fprintf(stdout, " Filter identifier is ");
switch (filter_id) {
case H5Z_FILTER_JPEG:
fprintf(stdout, "%d\n", filter_id);
fprintf(stdout, " Number of parameters is %d with the value %u\n", nelmts, values_out[0]);
fprintf(stdout, " To find more about the filter check %s\n", filter_name);
break;
default:
fprintf(stdout, "Not expected filter\n");
break;
}
fflush(stdout);
/*
* Read the data using the default properties.
*/
fprintf(stdout, "....Reading jpeg compressed data ................\n");
status = H5Dread(dset_id, H5T_NATIVE_UINT8, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata);
if (status < 0)
fprintf(stdout, "failed to read data.\n");
fflush(stdout);
/*
* Find the maximum value in the dataset, to verify that it was
* read correctly.
*/
for (i = 0; i < data_size; i++) {
/*printf("%d \n", rdata[i]); */
if (rdata[i] != wdata[i])
num_diff++;
}
/*
* Print the number of differences.
*/
fprintf(stdout, "JPEG quality=%d, percent of differing array elements=%f\n", JPEG_QUALITY,
100. * (double)num_diff / data_size);
/*
* Check that filter is registered with the library now.
*/
avail = H5Zfilter_avail(H5Z_FILTER_JPEG);
if (avail)
fprintf(stdout, "jpeg filter is available now since H5Dread triggered loading of the filter.\n");
ret_value = 0;
done:
fflush(stdout);
free(rdata);
free(wdata);
/*
* Close and release resources.
*/
if (dcpl_id >= 0)
H5Pclose(dcpl_id);
if (dset_id >= 0)
H5Dclose(dset_id);
if (space_id >= 0)
H5Sclose(space_id);
if (file_id >= 0)
H5Fclose(file_id);
return ret_value;
}
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