JPEG file IPTC meta info read example

iptc_jpeg_meta_info_viewer.c

#include <libiptcdata/iptc-data.h>
#include <libiptcdata/iptc-jpeg.h>
#include <jpeglib.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

void iptc_dataset_foreach_handler(IptcDataSet *dataset, void *datasetName) {
    IptcFormat format = iptc_dataset_get_format(dataset);
    printf("filter: %s\n\n", (char *) datasetName);

    //add filter
//    if (strcmp(dataset->info->name, datasetName) != 0) {
//        printf("ignore this dataset %s\n", dataset->info->name);
//        return;
//    }

    char *fmtStr = "unknown";
    switch (format) {
        case IPTC_FORMAT_BINARY:
            fmtStr = "binary";
            break;
        case IPTC_FORMAT_BYTE:
            fmtStr = "byte";
            break;
        case IPTC_FORMAT_SHORT:
            fmtStr = "short";
            break;
        case IPTC_FORMAT_LONG:
            fmtStr = "long";
            break;
        case IPTC_FORMAT_STRING:
            fmtStr = "string";
            break;
        case IPTC_FORMAT_NUMERIC_STRING:
            fmtStr = "numeric string";
            break;
        case IPTC_FORMAT_DATE:
            fmtStr = "date";
            break;
        case IPTC_FORMAT_TIME:
            fmtStr = "time";
            break;
        default:
            fmtStr = "unknown";
            break;
    }
    printf("format: %s\n", fmtStr);
    printf("info: %s, %s, %s\n", dataset->info->name, dataset->info->title, dataset->info->description);
    printf("data: %s, size: %d, tag: %d, record: %d\n", dataset->data, dataset->size, dataset->tag, dataset->record);
    printf("\n");

    iptc_dataset_unref(dataset);
}

int main(int argc, char **argv) {
    char *jpegFile = "/Users/jemy/XLab/iptc/iptc-base.jpg";
    IptcData *iptcData = iptc_data_new_from_jpeg(jpegFile);
    if (iptcData) {
        printf("image has iptc data: %d\n", iptcData->count);
        //iptc_data_foreach_dataset(iptcData, iptc_dataset_foreach_handler, "Keywords");

        //add new dataset
        IptcDataSet *newDataSet = iptc_dataset_new();
        iptc_dataset_set_tag(newDataSet, IPTC_RECORD_APP_2, IPTC_TAG_CITY);
        iptc_dataset_set_data(newDataSet, (unsigned char *) "上海", (unsigned int) strlen("上海"), IPTC_VALIDATE);
        int success = iptc_data_add_dataset(iptcData, newDataSet);
        printf("add status: %d\n", success);
        iptc_data_foreach_dataset(iptcData, iptc_dataset_foreach_handler, "City");


    } else {
        printf("image has no iptc data\n");
    }
}