GRAPHICS: Make JPEGDecoder request RGB output from libjpeg by default.

This fixes loading of JPEG files which contain RGB color space instead of YUV.
It is a pretty odd extension of JPEG files by Adobe which is indicated by this:
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#Adobe

To still support Groovie's need for YUV data I added some possibility to
request direct YUV output.

2 files changed, 90 insertions, 51 deletions

diff --git a/graphics/decoders/jpeg.cpp b/graphics/decoders/jpeg.cpp
index 891542c415..ba6292bbbd 100644
--- a/graphics/decoders/jpeg.cpp
+++ b/graphics/decoders/jpeg.cpp
@@ -25,7 +25,6 @@
 #define FORBIDDEN_SYMBOL_ALLOW_ALL
 
 #include "graphics/pixelformat.h"
-#include "graphics/yuv_to_rgb.h"
 #include "graphics/decoders/jpeg.h"
 
 #include "common/debug.h"
@@ -45,7 +44,7 @@ extern "C" {
 
 namespace Graphics {
 
-JPEGDecoder::JPEGDecoder() : ImageDecoder(), _rgbSurface(nullptr) {
+JPEGDecoder::JPEGDecoder() : ImageDecoder(), _surface(), _colorSpace(kColorSpaceRGBA) {
 }
 
 JPEGDecoder::~JPEGDecoder() {
@@ -53,31 +52,11 @@ JPEGDecoder::~JPEGDecoder() {
 }
 
 const Surface *JPEGDecoder::getSurface() const {
-	// Make sure we have loaded data
-	if (!_yComponent.getPixels())
-		return 0;
-
-	if (_rgbSurface)
-		return _rgbSurface;
-
-	// Create an RGBA8888 surface
-	_rgbSurface = new Graphics::Surface();
-	_rgbSurface->create(_yComponent.w, _yComponent.h, Graphics::PixelFormat(4, 8, 8, 8, 0, 24, 16, 8, 0));
-
-	YUVToRGBMan.convert444(_rgbSurface, Graphics::YUVToRGBManager::kScaleFull, (const byte *)_yComponent.getPixels(), (const byte *)_uComponent.getPixels(), (const byte *)_vComponent.getPixels(), _yComponent.w, _yComponent.h, _yComponent.pitch, _uComponent.pitch);
-
-	return _rgbSurface;
+	return &_surface;
 }
 
 void JPEGDecoder::destroy() {
-	if (_rgbSurface) {
-		_rgbSurface->free();
-		delete _rgbSurface;
-	}
-
-	_yComponent.free();
-	_uComponent.free();
-	_vComponent.free();
+	_surface.free();
 }
 
 #ifdef USE_JPEG
@@ -206,16 +185,33 @@ bool JPEGDecoder::loadStream(Common::SeekableReadStream &stream) {
 	// Read the file header
 	jpeg_read_header(&cinfo, TRUE);
 
-	// We request YUV output because Groovie requires it
-	cinfo.out_color_space = JCS_YCbCr;
+	// We can request YUV output because Groovie requires it
+	switch (_colorSpace) {
+	case kColorSpaceRGBA:
+		cinfo.out_color_space = JCS_RGB;
+		break;
+
+	case kColorSpaceYUV:
+		cinfo.out_color_space = JCS_YCbCr;
+		break;
+	}
 
 	// Actually start decompressing the image
 	jpeg_start_decompress(&cinfo);
 
-	// Allocate buffers for the YUV components
-	_yComponent.create(cinfo.output_width, cinfo.output_height, Graphics::PixelFormat::createFormatCLUT8());
-	_uComponent.create(cinfo.output_width, cinfo.output_height, Graphics::PixelFormat::createFormatCLUT8());
-	_vComponent.create(cinfo.output_width, cinfo.output_height, Graphics::PixelFormat::createFormatCLUT8());
+	// Allocate buffers for the output data
+	switch (_colorSpace) {
+	case kColorSpaceRGBA:
+		// We use RGBA8888 in this scenario
+		_surface.create(cinfo.output_width, cinfo.output_height, Graphics::PixelFormat(4, 8, 8, 8, 0, 24, 16, 8, 0));
+		break;
+
+	case kColorSpaceYUV:
+		// We use YUV with 3 bytes per pixel otherwise.
+		// This is pretty ugly since our PixelFormat cannot express YUV...
+		_surface.create(cinfo.output_width, cinfo.output_height, Graphics::PixelFormat(3, 0, 0, 0, 0, 0, 0, 0, 0));
+		break;
+	}
 
 	// Allocate buffer for one scanline
 	JDIMENSION pitch = cinfo.output_width * cinfo.output_components;
@@ -223,17 +219,35 @@ bool JPEGDecoder::loadStream(Common::SeekableReadStream &stream) {
 
 	// Go through the image data scanline by scanline
 	while (cinfo.output_scanline < cinfo.output_height) {
-		byte *yPtr = (byte *)_yComponent.getBasePtr(0, cinfo.output_scanline);
-		byte *uPtr = (byte *)_uComponent.getBasePtr(0, cinfo.output_scanline);
-		byte *vPtr = (byte *)_vComponent.getBasePtr(0, cinfo.output_scanline);
+		byte *dst = (byte *)_surface.getBasePtr(0, cinfo.output_scanline);
 
 		jpeg_read_scanlines(&cinfo, buffer, 1);
 
 		const byte *src = buffer[0];
-		for (int remaining = cinfo.output_width; remaining > 0; --remaining) {
-			*yPtr++ = *src++;
-			*uPtr++ = *src++;
-			*vPtr++ = *src++;
+		switch (_colorSpace) {
+		case kColorSpaceRGBA: {
+			for (int remaining = cinfo.output_width; remaining > 0; --remaining) {
+				byte r = *src++;
+				byte g = *src++;
+				byte b = *src++;
+				// We need to insert a alpha value of 255 (opaque) here.
+#ifdef SCUMM_BIG_ENDIAN
+				*dst++ = r;
+				*dst++ = g;
+				*dst++ = b;
+				*dst++ = 0xFF;
+#else
+				*dst++ = 0xFF;
+				*dst++ = b;
+				*dst++ = g;
+				*dst++ = r;
+#endif
+			}
+			} break;
+
+		case kColorSpaceYUV:
+			memcpy(dst, src, _surface.pitch);
+			break;
 		}
 	}
 
diff --git a/graphics/decoders/jpeg.h b/graphics/decoders/jpeg.h
index 53e7bb10c8..8460bc2698 100644
--- a/graphics/decoders/jpeg.h
+++ b/graphics/decoders/jpeg.h
@@ -46,23 +46,48 @@ public:
 	~JPEGDecoder();
 
 	// ImageDecoder API
-	void destroy();
-	bool loadStream(Common::SeekableReadStream &str);
-	const Surface *getSurface() const;
+	virtual void destroy();
+	virtual bool loadStream(Common::SeekableReadStream &str);
+	virtual const Surface *getSurface() const;
 
-	const Surface &getYComponent() const { return _yComponent; }
-	const Surface &getUComponent() const { return _uComponent; }
-	const Surface &getVComponent() const { return _vComponent; }
+	// Special API for JPEG
+	enum ColorSpace {
+		/**
+		 * Output 32bit RGBA data.
+		 *
+		 * This is the default output.
+		 */
+		kColorSpaceRGBA,
 
-private:
-	// mutable so that we can convert to RGB only during
-	// a getSurface() call while still upholding the
-	// const requirement in other ImageDecoders
-	mutable Graphics::Surface *_rgbSurface;
+		/**
+		 * 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 RGBA.
+	 *
+	 * @param outSpace The color space to output.
+	 */
+	void setOutputColorSpace(ColorSpace outSpace) { _colorSpace = outSpace; }
 
-	Graphics::Surface _yComponent;
-	Graphics::Surface _uComponent;
-	Graphics::Surface _vComponent;
+private:
+	Graphics::Surface _surface;
+	ColorSpace _colorSpace;
 };
 
 } // End of Graphics namespace