From 2706e527c214cfcc77502b3bdb639d5a341d3c1a Mon Sep 17 00:00:00 2001
From: Filippos Karapetis
Date: Tue, 16 Dec 2008 13:19:43 +0000
Subject: - Some more comments - The audio header is now decoded properly
 (still no audio support)

svn-id: r35392
---
 graphics/smk_player.cpp | 43 +++++++++++++++++++++++++++++++++++++------
 graphics/smk_player.h   | 15 ++++++++++++++-
 2 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/graphics/smk_player.cpp b/graphics/smk_player.cpp
index ccecea7b07..ba7c556f82 100644
--- a/graphics/smk_player.cpp
+++ b/graphics/smk_player.cpp
@@ -373,9 +373,20 @@ bool SMKPlayer::loadFile(const char *fileName) {
 	_header.height = _fileStream->readUint32LE();
 	_header.frames = _fileStream->readUint32LE();
 	_header.frameRate = (int32)_fileStream->readUint32LE();
+	// Flags are determined by which bit is set, which can be one of the following:
+	// 0 - set to 1 if file contains a ring frame.
+	// 1 - set to 1 if file is Y-interlaced
+	// 2 - set to 1 if file is Y-doubled
+	// If bits 1 or 2 are set, the frame should be scaled to twice its height
+    // before it is displayed.
 	_header.flags = _fileStream->readUint32LE();
 
-	unsigned int i;
+	// TODO: should we do any extra processing for Smacker files with ring frames?
+
+	// TODO: should we do any extra processing for Y-doubled videos? Are they the
+	// same as Y-interlaced videos?
+
+	uint32 i;
 	for (i = 0; i < 7; ++i)
 		_header.audioSize[i] = _fileStream->readUint32LE();
 
@@ -385,8 +396,26 @@ bool SMKPlayer::loadFile(const char *fileName) {
 	_header.fullSize = _fileStream->readUint32LE();
 	_header.typeSize = _fileStream->readUint32LE();
 
-	for (i = 0; i < 7; ++i)
-		_header.audioRate[i] = _fileStream->readUint32LE();
+	uint32 audioInfo;
+	for (i = 0; i < 7; ++i) {
+		// AudioRate - Frequency and format information for each sound track, up to 7 audio tracks.
+		// The 32 constituent bits have the following meaning:
+		// * bit 31 - data is compressed
+		// * bit 30 - indicates that audio data is present for this track
+		// * bit 29 - 1 = 16-bit audio; 0 = 8-bit audio
+		// * bit 28 - 1 = stereo audio; 0 = mono audio
+		// * bits 27-26 - if both set to zero - use v2 sound decompression
+		// * bits 25-24 - unused
+		// * bits 23-0 - audio sample rate 
+		audioInfo = _fileStream->readUint32LE();
+		_header.audioInfo[i].isCompressed = audioInfo & 0x80000000;
+		_header.audioInfo[i].hasAudio = audioInfo & 0x40000000;
+		_header.audioInfo[i].is16Bits = audioInfo & 0x20000000;
+		_header.audioInfo[i].isStereo = audioInfo & 0x10000000;
+		_header.audioInfo[i].hasV2Compression = !(audioInfo & 0x8000000) &&
+												!(audioInfo & 0x4000000);
+		_header.audioInfo[i].sampleRate = audioInfo & 0xFFFFFF;
+	}
 
 	_header.dummy = _fileStream->readUint32LE();
 
@@ -436,7 +465,7 @@ void SMKPlayer::closeFile() {
 }
 
 void SMKPlayer::copyFrameToBuffer(byte *dst, uint x, uint y, uint pitch) {
-	uint h = _header.height;
+	uint h = (_header.flags ? 2 : 1) * _header.height;
 	uint w = _header.width;
 
 	byte *src = _image;
@@ -462,13 +491,15 @@ bool SMKPlayer::decodeNextFrame() {
 		setPalette(_palette);
 	}
 
-	// TODO: Audio support
-	// Skip audio tracks for now
+	// Load audio tracks
 	for (i = 0; i < 7; ++i) {
 		if (!(_frameTypes[_currentSMKFrame] & (2 << i)))
 			continue;
 
 		uint32 len = _fileStream->readUint32LE();
+
+		// TODO: Audio support
+
 		//uint32 unpackedLen = _fileStream->readUint32LE();
 		_fileStream->skip(len - 4);
 	}
diff --git a/graphics/smk_player.h b/graphics/smk_player.h
index 796789949e..c184a3af2b 100644
--- a/graphics/smk_player.h
+++ b/graphics/smk_player.h
@@ -73,6 +73,9 @@ public:
 
 	/**
 	 * Returns the frame rate of the video
+	 * If > 0, fps are 1000 / FrameRate
+	 * If < 0, fps are 100000 / (-FrameRate)
+	 * If 0, fps are 10
 	 * @return the frame rate of the video
 	 */
 	int32 getFrameRate();
@@ -117,6 +120,15 @@ private:
 
 	uint32 _currentSMKFrame;
 
+	struct AudioInfo {
+		bool isCompressed;
+		bool hasAudio;
+		bool is16Bits;
+		bool isStereo;
+		bool hasV2Compression;
+		uint32 sampleRate;
+	};
+
 	struct {
 		uint32 signature;
 		uint32 width;
@@ -130,7 +142,7 @@ private:
 		uint32 mClrSize;
 		uint32 fullSize;
 		uint32 typeSize;
-		uint32 audioRate[7];
+		AudioInfo audioInfo[7];
 		uint32 dummy;
 	} _header;
 
@@ -151,6 +163,7 @@ private:
 
 	byte *_image;
 	byte *_palette;
+
 	// Possible runs of blocks
 	uint getBlockRun(int index) { return (index <= 58) ? index + 1 : 128 << (index - 59); }
 };
-- 
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