ImageGif.h

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/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
 
#ifndef META_OCEAN_MEDIA_OPEN_IMAGE_LIBRARIES_OIL_IMAGE_GIF_H
#define META_OCEAN_MEDIA_OPEN_IMAGE_LIBRARIES_OIL_IMAGE_GIF_H
 
#include "ocean/media/openimagelibraries/OpenImageLibraries.h"
 
#include "ocean/base/Frame.h"
 
namespace Ocean
{
 
namespace Media
{
 
namespace OpenImageLibraries
{
 
/**
 * This class implements read and write functions for Gif images.
 * @ingroup mediaoil
 */
class OCEAN_MEDIA_OIL_EXPORT ImageGif
{
    protected:
 
        /// Forward declaration.
        class SourceBuffer;
 
    public:
 
        /**
         * Decodes a GIF image from a given binary buffer.
         * @param buffer The buffer from which the image will be loaded, must be valid
         * @param size The size of the given buffer in bytes, with range [1, infinity)
         * @param maximalImages The maximal number of images that will be returned, with range [0, infinity), 0 to return all images
         * @return The frames containing the image information, an invalid frame if the image could not be loaded
         */
        static Frames decodeImages(const void* buffer, const size_t size, const size_t maximalImages = 0u);
 
        /**
         * Reads/loads all images from a specified gif file.
         * @param filename The name of the file from which the image will be loaded, must be valid
         * @param maximalImages The maximal number of images that will be returned, with range [0, infinity), 0 to return all images
         * @return The frame containing the image information, an invalid frame if the image could not be loaded
         * @see writeImage().
         */
        static Frames readImages(const std::string& filename, const size_t maximalImages = 0u);
 
    protected:
 
        /**
         * Verifies whether the provided GIF is valid or corrupt.
         * @param buffer The buffer from which the image will be loaded, must be valid
         * @param size The size of the given buffer in bytes, with range [1, infinity)
         * @return True, if the GIF is valid
         */
        static bool verifyGif(const void* buffer, const size_t size);
};
 
}
 
}
 
}
 
#endif // META_OCEAN_MEDIA_OPEN_IMAGE_LIBRARIES_OIL_IMAGE_GIF_H