1 files changed, 140 insertions, 0 deletions
diff --git a/image/codecs/msrle4.cpp b/image/codecs/msrle4.cpp
new file mode 100644
index 0000000000..cd9a8717bc
--- /dev/null
+++ b/image/codecs/msrle4.cpp
@@ -0,0 +1,140 @@
+/* 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 2
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+// Based off ffmpeg's msrledec.c
+#include "common/debug.h"
+#include "image/codecs/msrle4.h"
+#include "common/stream.h"
+#include "common/textconsole.h"
+#include "common/util.h"
+namespace Image {
+
+MSRLE4Decoder::MSRLE4Decoder(uint16 width, uint16 height, byte bitsPerPixel) {
+	_surface = new Graphics::Surface();
+	_surface->create(width, height, Graphics::PixelFormat::createFormatCLUT8());
+	_bitsPerPixel = bitsPerPixel;
+}
+
+MSRLE4Decoder::~MSRLE4Decoder() {
+	_surface->free();
+	delete _surface;
+}
+
+const Graphics::Surface *MSRLE4Decoder::decodeFrame(Common::SeekableReadStream &stream) {
+	if (_bitsPerPixel == 4) {
+		decode4(stream);
+	} else
+		error("Unhandled %d bit Microsoft RLE encoding", _bitsPerPixel);
+
+	return _surface;
+}
+
+void MSRLE4Decoder::decode4(Common::SeekableReadStream &stream) {
+	int x = 0;
+	int y = _surface->h - 1;
+
+	byte *output     = (byte *)_surface->getBasePtr(x, y);
+	byte *output_end = (byte *)_surface->getBasePtr(_surface->w, y);
+
+	while (!stream.eos()) {
+		byte count = stream.readByte();
+
+		if (count == 0) {
+			byte value = stream.readByte();
+
+			if (value == 0) {
+				// End of line
+
+				x = 0;
+				y--;
+				output = (byte *)_surface->getBasePtr(x, y);
+			} else if (value == 1) {
+				// End of image
+
+				return;
+			} else if (value == 2) {
+				// Skip
+
+				count = stream.readByte();
+				value = stream.readByte();
+
+				x += count;
+				y -= value;
+
+				if (y < 0) {
+					warning("MS RLE Codec: Skip beyond picture bounds");
+					return;
+				}
+
+				output = (byte *)_surface->getBasePtr(x, y);;
+
+			} else {
+				// Copy data
+
+				int odd_pixel = value & 1;
+				int rle_code = (value + 1) / 2;
+				int extra_byte = rle_code & 0x01;
+
+				if (output + value > output_end) {
+					stream.skip(rle_code + extra_byte);
+					continue;
+				}
+
+				for (int i = 0; i < rle_code; i++) {
+					byte color = stream.readByte();
+					*output++ = (color & 0xf0) >> 4;
+					if (i + 1 == rle_code && odd_pixel) {
+						break;
+					}
+					*output++ = color & 0x0f;
+				}
+
+				if (extra_byte)
+					stream.skip(1);
+
+				x += value;
+			}
+
+		} else {
+			// Run data
+
+			if (output + count > output_end)
+				continue;
+
+			byte color = stream.readByte();
+
+			for (int i = 0; i < count; i++, x++) {
+				*output++ = (color & 0xf0) >> 4;
+				i++;
+				x++;
+				if (i == count)
+					break;
+				*output++ = color & 0x0f;
+			}
+		}
+
+	}
+
+	warning("MS RLE Codec: No end-of-picture code");
+}
+
+} // End of namespace Image