C

Decode Base64 Image String (GIF, JPG, etc.) and Save to File

I have an XML response that includes a base 64 encoded image string (UPS label). It's a huge string and I need to save it as a gif file on my users pc.

This example shows how to do it..

C

#include <C_CkBinData.h>
#include <C_CkXml.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkBinData bd;
    const char *x;
    HCkXml xml;
    const char *gifBase64;

    success = FALSE;

    bd = CkBinData_Create();

    // I created an extra-small GIF image for this example..
    success = CkBinData_LoadFile(bd,"qa_data/gif/xsmall.gif");
    if (success != TRUE) {
        printf("Failed to load GIF image file.\n");
        CkBinData_Dispose(bd);
        return;
    }

    // Show GIF bytes as base64:
    printf("%s\n",CkBinData_getEncoded(bd,"base64"));

    // This particular GIF in base64 is this:
    // R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7

    // Let's begin with an XML string:
    x = "<abc><def>R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7</def></abc>";

    xml = CkXml_Create();
    success = CkXml_LoadXml(xml,x);

    // Get the base64 string:
    gifBase64 = CkXml_getChildContent(xml,"def");

    printf("%s\n",gifBase64);

    // Load bd with the base64 decoded bytes.  
    CkBinData_Clear(bd);
    CkBinData_AppendEncoded(bd,gifBase64,"base64");

    // Save to a GIF file.
    success = CkBinData_WriteFile(bd,"qa_output/xsmall.gif");


    CkBinData_Dispose(bd);
    CkXml_Dispose(xml);

    }