From 4702681be2f5a1e3655f01dfb285e653400b3601 Mon Sep 17 00:00:00 2001
From: Torbjörn Andersson
Date: Sun, 25 Mar 2018 07:37:49 +0200
Subject: IMAGE: Explicitly initialize CinePak codebooks

Starship Titanic produces lots of "uninitialized value" warnings
at the very beginning of the game, when turning right. This is
because in the very first movie frame it uses codebooks that have
not been loaded. Explicitly set their data to 0 to guarantee
consistent behavior.
---
 image/codecs/cinepak.cpp | 20 +++++++++++++++++++-
 image/codecs/cinepak.h   |  1 +
 2 files changed, 20 insertions(+), 1 deletion(-)

(limited to 'image/codecs')

diff --git a/image/codecs/cinepak.cpp b/image/codecs/cinepak.cpp
index f356e87971..1c477c82d5 100644
--- a/image/codecs/cinepak.cpp
+++ b/image/codecs/cinepak.cpp
@@ -405,8 +405,13 @@ const Graphics::Surface *CinepakDecoder::decodeFrame(Common::SeekableReadStream
 	_curFrame.height = stream.readUint16BE();
 	_curFrame.stripCount = stream.readUint16BE();
 
-	if (!_curFrame.strips)
+	if (!_curFrame.strips) {
 		_curFrame.strips = new CinepakStrip[_curFrame.stripCount];
+		for (uint16 i = 0; i < _curFrame.stripCount; i++) {
+			initializeCodebook(i, 1);
+			initializeCodebook(i, 4);
+		}
+	}
 
 	debug(4, "Cinepak Frame: Width = %d, Height = %d, Strip Count = %d", _curFrame.width, _curFrame.height, _curFrame.stripCount);
 
@@ -499,6 +504,19 @@ const Graphics::Surface *CinepakDecoder::decodeFrame(Common::SeekableReadStream
 	return _curFrame.surface;
 }
 
+void CinepakDecoder::initializeCodebook(uint16 strip, byte codebookType) {
+	CinepakCodebook *codebook = (codebookType == 1) ? _curFrame.strips[strip].v1_codebook : _curFrame.strips[strip].v4_codebook;
+
+	for (uint16 i = 0; i < 256; i++) {
+		memset(codebook[i].y, 0, 4);
+		codebook[i].u = 0;
+		codebook[i].v = 0;
+
+		if (_ditherType == kDitherTypeQT)
+			ditherCodebookQT(strip, codebookType, i);
+	}
+}
+
 void CinepakDecoder::loadCodebook(Common::SeekableReadStream &stream, uint16 strip, byte codebookType, byte chunkID, uint32 chunkSize) {
 	CinepakCodebook *codebook = (codebookType == 1) ? _curFrame.strips[strip].v1_codebook : _curFrame.strips[strip].v4_codebook;
 
diff --git a/image/codecs/cinepak.h b/image/codecs/cinepak.h
index 4efb1191cc..3b0fe477a6 100644
--- a/image/codecs/cinepak.h
+++ b/image/codecs/cinepak.h
@@ -94,6 +94,7 @@ private:
 	byte *_colorMap;
 	DitherType _ditherType;
 
+	void initializeCodebook(uint16 strip, byte codebookType);
 	void loadCodebook(Common::SeekableReadStream &stream, uint16 strip, byte codebookType, byte chunkID, uint32 chunkSize);
 	void decodeVectors(Common::SeekableReadStream &stream, uint16 strip, byte chunkID, uint32 chunkSize);
 
-- 
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