// ***************************************************************** -*- C++ -*-

/*

  Abstract : Sample program showing how to set the Exif comment of an image,

             Exif.Photo.UserComment

  File:      exifcomment.cpp

  Author(s): Andreas Huggel (ahu) <ahuggel@gmx.net>

  History  : 10-May-04, ahu: created

             16-Jan-05, ahu: updated using CommentValue and operator trickery

 */

// *****************************************************************************

// included header files

#include <exiv2/exiv2.hpp>

#include <iostream>

#include <cassert>

// *****************************************************************************

// Main

int main(int argc, char* const argv[])

try {

    if (argc != 2) {

        std::cout << "Usage: " << argv[0] << " file\n";

        return 1;

    }

    Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(argv[1]);

    assert (image.get() != 0);

    image->readMetadata();

    Exiv2::ExifData &exifData = image->exifData();

    /*

      Exiv2 uses a CommentValue for Exif user comments. The format of the

      comment string includes an optional charset specification at the beginning:

      [charset=["]Ascii|Jis|Unicode|Undefined["] ]comment

      Undefined is used as a default if the comment doesn't start with a charset

      definition.

      Following are a few examples of valid comments. The last one is written to

      the file.

     */

    exifData["Exif.Photo.UserComment"]

        = "charset=\"Unicode\" An Unicode Exif comment added with Exiv2";

    exifData["Exif.Photo.UserComment"]

        = "charset=\"Undefined\" An undefined Exif comment added with Exiv2";

    exifData["Exif.Photo.UserComment"]

        = "Another undefined Exif comment added with Exiv2";

    exifData["Exif.Photo.UserComment"]

        = "charset=Ascii An ASCII Exif comment added with Exiv2";

    std::cout << "Writing user comment '"

              << exifData["Exif.Photo.UserComment"]

              << "' back to the image\n";

    image->writeMetadata();

    return 0;

}

catch (Exiv2::AnyError& e) {

    std::cout << "Caught Exiv2 exception '" << e << "'\n";

    return -1;

}