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image/jpeg.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef IMAGE_JPEG_H
+#define IMAGE_JPEG_H
+
+#include "graphics/palette.h"
+#include "graphics/surface.h"
+#include "image/image_decoder.h"
+#include "image/codecs/codec.h"
+
+namespace Common {
+class SeekableReadStream;
+}
+
+namespace Image {
+
+/**
+ * @defgroup image_jpeg JPEG decoder
+ * @ingroup image
+ *
+ * @brief Decoder for JPEG images.
+ *
+ * Used in engines:
+ * - groovie
+ * - mohawk
+ * - vcruise
+ * - wintermute
+ * @{
+ */
+
+class JPEGDecoder : public ImageDecoder, public Codec {
+public:
+	JPEGDecoder();
+	~JPEGDecoder();
+
+	// ImageDecoder API
+	void destroy() override;
+	bool loadStream(Common::SeekableReadStream &str) override;
+	const Graphics::Surface *getSurface() const override;
+	const Graphics::Palette &getPalette() const override { return _palette; }
+
+	// Codec API
+	const Graphics::Surface *decodeFrame(Common::SeekableReadStream &stream) override;
+	void setCodecAccuracy(CodecAccuracy accuracy) override;
+	Graphics::PixelFormat getPixelFormat() const override;
+	bool setOutputPixelFormat(const Graphics::PixelFormat &format) override {
+		if (format.isCLUT8())
+			return false;
+		_requestedPixelFormat = format;
+		return true;
+	}
+
+	// Special API for JPEG
+	enum ColorSpace {
+		/**
+		 * Output RGB data in the pixel format specified using `setOutputPixelFormat`.
+		 *
+		 * This is the default output.
+		 */
+		kColorSpaceRGB,
+
+		/**
+		 * Output (interleaved) YUV data.
+		 *
+		 * Be aware that some images cannot be output in YUV mode.
+		 * These are (non-standard) JPEG images which are in RGB colorspace.
+		 *
+		 * The resulting Surface will have a PixelFormat with 3 bytes per
+		 * pixel and the remaining entries are completely zeroed. This works
+		 * around the fact that PixelFormat can only describe RGB formats.
+		 *
+		 * You should only use this when you are really aware of what you are
+		 * doing!
+		 */
+		kColorSpaceYUV
+	};
+
+	/**
+	 * Request the output color space. This can be used to obtain raw YUV
+	 * data from the JPEG file. But this might not work for all files!
+	 *
+	 * The decoder itself defaults to RGB.
+	 *
+	 * @param outSpace The color space to output.
+	 */
+	void setOutputColorSpace(ColorSpace outSpace) { _colorSpace = outSpace; }
+
+private:
+	// TODO: Avoid inheriting from multiple superclasses that have identical member functions.
+	using Codec::getPalette;
+	Graphics::Surface _surface;
+	Graphics::Palette _palette;
+	ColorSpace _colorSpace;
+	Graphics::PixelFormat _requestedPixelFormat;
+	CodecAccuracy _accuracy;
+
+	Graphics::PixelFormat getByteOrderRgbPixelFormat() const;
+};
+/** @} */
+} // End of namespace Image
+
+#endif