Renamed the DXA, SMK and FLIC video decoders to reflect the fact that they're decoders, not players

svn-id: r40759

1 files changed, 859 insertions, 0 deletions

diff --git a/graphics/video/smk_decoder.cpp b/graphics/video/smk_decoder.cpp
new file mode 100644
index 0000000000..3d83bbd8ea
--- /dev/null
+++ b/graphics/video/smk_decoder.cpp
@@ -0,0 +1,859 @@
+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+// Based on http://wiki.multimedia.cx/index.php?title=Smacker
+// and the FFmpeg Smacker decoder (libavcodec/smacker.c), revision 16143
+// http://svn.ffmpeg.org/ffmpeg/trunk/libavcodec/smacker.c?revision=16143&view=markup
+
+#include "graphics/video/smk_decoder.h"
+
+#include "common/archive.h"
+#include "common/array.h"
+#include "common/endian.h"
+#include "common/util.h"
+#include "common/stream.h"
+#include "common/system.h"
+
+#include "sound/mixer.h"
+#include "sound/audiostream.h"
+
+namespace Graphics {
+
+enum SmkBlockTypes {
+	SMK_BLOCK_MONO = 0,
+	SMK_BLOCK_FULL = 1,
+	SMK_BLOCK_SKIP = 2,
+	SMK_BLOCK_FILL = 3
+};
+
+/*
+ * class BitStream
+ * Keeps a two-byte lookahead, so overallocate buf by 2 bytes if
+ * you want to avoid OOB reads.
+ */
+
+class BitStream {
+public:
+	BitStream(byte *buf, uint32 length)
+		: _buf(buf), _end(buf+length), _curBit(8) {
+		_curBytes  = *_buf++;
+		_curBytes |= *_buf++ << 8;
+	}
+
+	bool getBit();
+	byte getBits8();
+
+	byte peek8() const;
+	void skip(int n);
+
+private:
+	byte *_buf;
+	byte *_end;
+	uint16 _curBytes;
+	byte  _curBit;
+};
+
+bool BitStream::getBit() {
+	bool v = _curBytes & 1;
+
+	_curBytes >>= 1;
+
+	if (--_curBit == 0) {
+		_curBytes |= *_buf++ << 8;
+		_curBit = 8;
+	}
+
+	return v;
+}
+
+byte BitStream::getBits8() {
+	byte v = _curBytes & 0xff;
+	_curBytes >>= 8;
+	_curBytes |= *_buf++ << _curBit;
+	return v;
+}
+
+byte BitStream::peek8() const {
+	return _curBytes & 0xff;
+}
+
+void BitStream::skip(int n) {
+	assert(n <= 8);
+	_curBytes >>= n;
+
+	if (_curBit > n) {
+		_curBit -= n;
+	} else {
+		_curBit = _curBit + 8 - n;
+		_curBytes |= *_buf++ << _curBit;
+	}
+}
+
+/*
+ * class SmallHuffmanTree
+ * A Huffman-tree to hold 8-bit values.
+ * Unoptimized since it's only used during smk initialization.
+ */
+
+class SmallHuffmanTree {
+public:
+	SmallHuffmanTree(BitStream &bs) : _bs(bs) {
+		uint32 bit = _bs.getBit();
+		assert(bit);
+
+		decodeTree(0);
+
+		bit = _bs.getBit();
+		assert(!bit);
+	}
+
+	uint16 getCode(BitStream &bs);
+private:
+	enum {
+		SMK_NODE = 0x8000
+	};
+
+	int decodeTree(int length);
+
+	Common::Array<uint16> _tree;
+	BitStream &_bs;
+};
+
+int SmallHuffmanTree::decodeTree(int length) {
+	if (!_bs.getBit()) { // Leaf
+		uint16 v = _bs.getBits8();
+
+		_tree.push_back(v);
+		return 1;
+	}
+
+	_tree.push_back(0); // placeholder for r1
+	int t = _tree.size() - 1;
+
+	int r1 = decodeTree(length + 1);
+
+	_tree[t] = (SMK_NODE | r1);
+
+	int r2 = decodeTree(length + 1);
+
+	return r1+r2+1;
+}
+
+uint16 SmallHuffmanTree::getCode(BitStream &bs) {
+	uint16 *p = &_tree[0];
+
+	while (*p & SMK_NODE) {
+		if (bs.getBit())
+			p += *p & ~SMK_NODE;
+		p++;
+	}
+
+	return *p;
+}
+
+/*
+ * class BigHuffmanTree
+ * A Huffman-tree to hold 16-bit values.
+ * Contains the beginnings of an optimization.
+ */
+
+class BigHuffmanTree {
+public:
+	BigHuffmanTree(BitStream &bs);
+
+	void reset();
+	uint32 getCode(BitStream &bs);
+private:
+	enum {
+		SMK_NODE = 0x80000000
+	};
+
+	int decodeTree(uint32 prefix, int length);
+
+	Common::Array<uint32> _tree;
+	uint32 _last[3];
+
+	int _prefixtree[256];
+	int _prefixlength[256];
+
+	/* Used during construction */
+	BitStream &_bs;
+	uint32 _markers[3];
+	SmallHuffmanTree *_loBytes;
+	SmallHuffmanTree *_hiBytes;
+};
+
+BigHuffmanTree::BigHuffmanTree(BitStream &bs)
+	: _bs(bs) {
+	uint32 bit = _bs.getBit();
+	if (!bit) {
+		_tree.push_back(0);
+		_last[0] = _last[1] = _last[2] = 0;
+		return;
+	}
+
+	int i;
+	for (i = 0; i < 256; ++i)
+		_prefixtree[i] = 0;
+
+	_loBytes = new SmallHuffmanTree(_bs);
+	_hiBytes = new SmallHuffmanTree(_bs);
+
+	_markers[0] = _bs.getBits8() | (_bs.getBits8() << 8);
+	_markers[1] = _bs.getBits8() | (_bs.getBits8() << 8);
+	_markers[2] = _bs.getBits8() | (_bs.getBits8() << 8);
+
+	_last[0] = _last[1] = _last[2] = 0xffffffff;
+
+	decodeTree(0, 0);
+	bit = _bs.getBit();
+	assert(!bit);
+
+	for (i = 0; i < 3; ++i) {
+		if (_last[i] == 0xffffffff) {
+			_tree.push_back(0);
+			_last[i] = _tree.size() - 1;
+		}
+	}
+
+	delete _loBytes;
+	delete _hiBytes;
+}
+
+void BigHuffmanTree::reset() {
+	_tree[_last[0]] = _tree[_last[1]] = _tree[_last[2]] = 0;
+}
+
+int BigHuffmanTree::decodeTree(uint32 prefix, int length) {
+	uint32 bit = _bs.getBit();
+
+	if (!bit) { // Leaf
+		uint32 lo = _loBytes->getCode(_bs);
+		uint32 hi = _hiBytes->getCode(_bs);
+
+		uint32 v = (hi << 8) | lo;
+		_tree.push_back(v);
+
+		int t = _tree.size() - 1;
+
+		if (length <= 8) {
+			uint32 i;
+			for (i = 0; i < 256; i += (1 << length)) {
+				_prefixtree[prefix | i] = t;
+				_prefixlength[prefix | i] = length;
+			}
+		}
+
+		int i;
+		for (i = 0; i < 3; ++i) {
+			if (_markers[i] == v) {
+				_last[i] = t;
+				_tree[t] = 0;
+			}
+		}
+
+		return 1;
+	}
+
+	_tree.push_back(0); // placeholder for r1
+	int t = _tree.size() - 1;
+
+	if (length == 8) {
+		_prefixtree[prefix] = t;
+		_prefixlength[prefix] = 8;
+	}
+
+	int r1 = decodeTree(prefix, length + 1);
+
+	_tree[t] = SMK_NODE | r1;
+
+	int r2 = decodeTree(prefix | (1 << length), length + 1);
+	return r1+r2+1;
+}
+
+uint32 BigHuffmanTree::getCode(BitStream &bs) {
+	uint32 *p = &_tree[0];
+
+	byte peek = bs.peek8();
+	p = &_tree[_prefixtree[peek]];
+	bs.skip(_prefixlength[peek]);
+
+	while (*p & SMK_NODE) {
+		if (bs.getBit())
+			p += (*p) & ~SMK_NODE;
+		p++;
+	}
+
+	uint32 v = *p;
+	if (v != _tree[_last[0]]) {
+		_tree[_last[2]] = _tree[_last[1]];
+		_tree[_last[1]] = _tree[_last[0]];
+		_tree[_last[0]] = v;
+	}
+
+	return v;
+}
+
+SmackerDecoder::SmackerDecoder(Audio::Mixer *mixer)
+	: _audioStarted(false), _audioStream(0), _mixer(mixer) {
+}
+
+SmackerDecoder::~SmackerDecoder() {
+	closeFile();
+}
+
+int SmackerDecoder::getHeight() {
+	if (!_fileStream)
+		return 0;
+	return (_header.flags ? 2 : 1) * _videoInfo.height;
+}
+
+int32 SmackerDecoder::getAudioLag() {
+	if (!_fileStream)
+		return 0;
+
+	int32 frameDelay = getFrameDelay();
+	int32 videoTime = _videoInfo.currentFrame * frameDelay;
+	int32 audioTime;
+
+	if (!_audioStream) {
+		/* No audio.
+		   Calculate the lag by how much time has gone by since the first frame
+		   and how much time *should* have passed.
+		*/
+
+		audioTime = (g_system->getMillis() - _videoInfo.startTime) * 100;
+	} else
+		audioTime = (((int32) _mixer->getSoundElapsedTime(_audioHandle)) * 100);
+
+	return videoTime - audioTime;
+}
+
+bool SmackerDecoder::loadFile(const char *fileName) {
+	int32 frameRate;
+
+	closeFile();
+
+	_fileStream = SearchMan.createReadStreamForMember(fileName);
+	if (!_fileStream)
+		return false;
+
+	// Seek to the first frame
+	_videoInfo.currentFrame = 0;
+	_header.signature = _fileStream->readUint32BE();
+
+	// No BINK support available
+	if (_header.signature == MKID_BE('BIKi')) {
+		delete _fileStream;
+		_fileStream = 0;
+		return false;
+	}
+
+	assert(_header.signature == MKID_BE('SMK2') || _header.signature == MKID_BE('SMK4'));
+
+	_videoInfo.width = _fileStream->readUint32LE();
+	_videoInfo.height = _fileStream->readUint32LE();
+	_videoInfo.frameCount = _fileStream->readUint32LE();
+	frameRate = _fileStream->readSint32LE();
+
+	if (frameRate > 0) {
+		_videoInfo.frameRate = 1000 / frameRate;
+		_videoInfo.frameDelay = frameRate * 100;
+	} else if (frameRate < 0) {
+		_videoInfo.frameRate = 100000 / (-frameRate);
+		_videoInfo.frameDelay = -frameRate;
+	} else {
+		_videoInfo.frameRate = 10;
+		_videoInfo.frameDelay = 10000;
+	}
+
+	// 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();
+
+	// 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();
+
+	_header.treesSize = _fileStream->readUint32LE();
+	_header.mMapSize = _fileStream->readUint32LE();
+	_header.mClrSize = _fileStream->readUint32LE();
+	_header.fullSize = _fileStream->readUint32LE();
+	_header.typeSize = _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;
+
+		if (_header.audioInfo[i].hasAudio && i == 0) {
+			byte flags = 0;
+
+			if (_header.audioInfo[i].is16Bits)
+				flags = flags | Audio::Mixer::FLAG_16BITS;
+
+			if (_header.audioInfo[i].isStereo)
+				flags = flags | Audio::Mixer::FLAG_STEREO;
+
+			_audioStream = Audio::makeAppendableAudioStream(_header.audioInfo[i].sampleRate, flags);
+		}
+	}
+
+	_header.dummy = _fileStream->readUint32LE();
+
+	_frameSizes = (uint32 *)malloc(_videoInfo.frameCount * sizeof(uint32));
+	for (i = 0; i < _videoInfo.frameCount; ++i)
+		_frameSizes[i] = _fileStream->readUint32LE();
+
+	_frameTypes = (byte *)malloc(_videoInfo.frameCount);
+	for (i = 0; i < _videoInfo.frameCount; ++i)
+		_frameTypes[i] = _fileStream->readByte();
+
+	Common::Array<byte> huffmanTrees;
+	huffmanTrees.resize(_header.treesSize + 2);
+	_fileStream->read(&huffmanTrees[0], _header.treesSize);
+	huffmanTrees[_header.treesSize] = 0;
+	huffmanTrees[_header.treesSize + 1] = 0;
+
+	BitStream bs(&huffmanTrees[0], _header.treesSize);
+
+	_MMapTree = new BigHuffmanTree(bs);
+	_MClrTree = new BigHuffmanTree(bs);
+	_FullTree = new BigHuffmanTree(bs);
+	_TypeTree = new BigHuffmanTree(bs);
+
+	_videoFrameBuffer = (byte *)malloc(2 * _videoInfo.width * _videoInfo.height);
+	memset(_videoFrameBuffer, 0, 2 * _videoInfo.width * _videoInfo.height);
+	_palette = (byte *)malloc(3 * 256);
+	memset(_palette, 0, 3 * 256);
+
+	_videoInfo.firstframeOffset = _fileStream->pos();
+
+	return true;
+}
+
+void SmackerDecoder::closeFile() {
+	if (!_fileStream)
+		return;
+
+	if (_audioStarted && _audioStream) {
+		_mixer->stopHandle(_audioHandle);
+		_audioStream = 0;
+		_audioStarted = false;
+	}
+
+	delete _fileStream;
+	_fileStream = 0;
+
+	delete _MMapTree;
+	delete _MClrTree;
+	delete _FullTree;
+	delete _TypeTree;
+
+	free(_frameSizes);
+	free(_frameTypes);
+	free(_videoFrameBuffer);
+	free(_palette);
+}
+
+bool SmackerDecoder::decodeNextFrame() {
+	uint i;
+	uint32 chunkSize = 0;
+	uint32 dataSizeUnpacked = 0;
+
+	uint32 startPos = _fileStream->pos();
+
+	if (_videoInfo.currentFrame == 0)
+		_videoInfo.startTime = g_system->getMillis();
+
+	// Check if we got a frame with palette data, and
+	// call back the virtual setPalette function to set
+	// the current palette
+	if (_frameTypes[_videoInfo.currentFrame] & 1) {
+		unpackPalette();
+		setPalette(_palette);
+	}
+
+	// Load audio tracks
+	for (i = 0; i < 7; ++i) {
+		if (!(_frameTypes[_videoInfo.currentFrame] & (2 << i)))
+			continue;
+
+		chunkSize = _fileStream->readUint32LE();
+		chunkSize -= 4;    // subtract the first 4 bytes (chunk size)
+
+		if (_header.audioInfo[i].isCompressed) {
+			dataSizeUnpacked = _fileStream->readUint32LE();
+			chunkSize -= 4;    // subtract the next 4 bytes (unpacked data size)
+		} else {
+			dataSizeUnpacked = 0;
+		}
+
+		if (_header.audioInfo[i].hasAudio && chunkSize > 0 && i == 0) {
+			// If it's track 0, play the audio data
+			byte *soundBuffer = new byte[chunkSize + 2];
+
+			_fileStream->read(soundBuffer, chunkSize);
+			soundBuffer[chunkSize] = 0;
+			soundBuffer[chunkSize + 1] = 0;
+
+			if (_header.audioInfo[i].isCompressed) {
+				// Compressed audio (Huffman DPCM encoded)
+				queueCompressedBuffer(soundBuffer, chunkSize, dataSizeUnpacked, i);
+				delete[] soundBuffer;
+			} else {
+				// Uncompressed audio (PCM)
+				_audioStream->queueBuffer(soundBuffer, chunkSize);
+				// The sound buffer will be deleted by AppendableAudioStream
+			}
+
+			if (!_audioStarted) {
+				_mixer->playInputStream(Audio::Mixer::kPlainSoundType, &_audioHandle, _audioStream, -1, 255);
+				_audioStarted = true;
+			}
+		} else {
+			// Ignore the rest of the audio tracks, if they exist
+			// TODO: Are there any Smacker videos with more than one audio stream?
+			// If yes, we should play the rest of the audio streams as well
+			if (chunkSize > 0)
+				_fileStream->skip(chunkSize);
+		}
+	}
+
+	uint32 frameSize = _frameSizes[_videoInfo.currentFrame] & ~3;
+
+	if (_fileStream->pos() - startPos > frameSize)
+		exit(1);
+
+	uint32 frameDataSize = frameSize - (_fileStream->pos() - startPos);
+
+	_frameData = (byte *)malloc(frameDataSize + 2);
+	_fileStream->read(_frameData, frameDataSize);
+	_frameData[frameDataSize] = 0;
+	_frameData[frameDataSize + 1] = 0;
+
+	BitStream bs(_frameData, frameDataSize);
+
+	_MMapTree->reset();
+	_MClrTree->reset();
+	_FullTree->reset();
+	_TypeTree->reset();
+
+	uint bw = _videoInfo.width / 4;
+	uint bh = _videoInfo.height / 4;
+	uint stride = _videoInfo.width;
+	uint block = 0, blocks = bw*bh;
+
+	uint doubleY = _header.flags ? 2 : 1;
+
+	byte *out;
+	uint type, run, j, mode;
+	uint32 p1, p2, clr, map;
+	byte hi, lo;
+
+	while (block < blocks) {
+		type = _TypeTree->getCode(bs);
+		run = getBlockRun((type >> 2) & 0x3f);
+
+		switch (type & 3) {
+		case SMK_BLOCK_MONO:
+			while (run-- && block < blocks) {
+				clr = _MClrTree->getCode(bs);
+				map = _MMapTree->getCode(bs);
+				out = _videoFrameBuffer + (block / bw) * (stride * 4 * doubleY) + (block % bw) * 4;
+				hi = clr >> 8;
+				lo = clr & 0xff;
+				for (i = 0; i < 4; i++) {
+					for (j = 0; j < doubleY; j++) {
+						out[0] = (map & 1) ? hi : lo;
+						out[1] = (map & 2) ? hi : lo;
+						out[2] = (map & 4) ? hi : lo;
+						out[3] = (map & 8) ? hi : lo;
+						out += stride;
+					}
+					map >>= 4;
+				}
+				++block;
+			}
+			break;
+		case SMK_BLOCK_FULL:
+			// Smacker v2 has one mode, Smacker v4 has three
+			if (_header.signature == MKID_BE('SMK2')) {
+				mode = 0;
+			} else {
+				// 00 - mode 0
+				// 10 - mode 1
+				// 01 - mode 2
+				mode = 0;
+				if (bs.getBit()) {
+					mode = 1;
+				} else if (bs.getBit()) {
+					mode = 2;
+				}
+			}
+
+			while (run-- && block < blocks) {
+				out = _videoFrameBuffer + (block / bw) * (stride * 4 * doubleY) + (block % bw) * 4;
+				switch (mode) {
+					case 0:
+						for (i = 0; i < 4; ++i) {
+							p1 = _FullTree->getCode(bs);
+							p2 = _FullTree->getCode(bs);
+							for (j = 0; j < doubleY; ++j) {
+								out[2] = p1 & 0xff;
+								out[3] = p1 >> 8;
+								out[0] = p2 & 0xff;
+								out[1] = p2 >> 8;
+								out += stride;
+							}
+						}
+						break;
+					case 1:
+						p1 = _FullTree->getCode(bs);
+						out[0] = out[1] = p1 & 0xFF;
+						out[2] = out[3] = p1 >> 8;
+						out += stride;
+						out[0] = out[1] = p1 & 0xFF;
+						out[2] = out[3] = p1 >> 8;
+						out += stride;
+						p2 = _FullTree->getCode(bs);
+						out[0] = out[1] = p2 & 0xFF;
+						out[2] = out[3] = p2 >> 8;
+						out += stride;
+						out[0] = out[1] = p2 & 0xFF;
+						out[2] = out[3] = p2 >> 8;
+						out += stride;
+						break;
+					case 2:
+						for (i = 0; i < 2; i++) {
+							// We first get p2 and then p1
+							// Check ffmpeg thread "[PATCH] Smacker video decoder bug fix"
+							// http://article.gmane.org/gmane.comp.video.ffmpeg.devel/78768
+							p2 = _FullTree->getCode(bs);
+							p1 = _FullTree->getCode(bs);
+							for (j = 0; j < doubleY; ++j) {
+								out[0] = p1 & 0xff;
+								out[1] = p1 >> 8;
+								out[2] = p2 & 0xff;
+								out[3] = p2 >> 8;
+								out += stride;
+							}
+							for (j = 0; j < doubleY; ++j) {
+								out[0] = p1 & 0xff;
+								out[1] = p1 >> 8;
+								out[2] = p2 & 0xff;
+								out[3] = p2 >> 8;
+								out += stride;
+							}
+						}
+						break;
+				}
+				++block;
+			}
+			break;
+		case SMK_BLOCK_SKIP:
+			while (run-- && block < blocks)
+				block++;
+			break;
+		case SMK_BLOCK_FILL:
+			uint32 col;
+			mode = type >> 8;
+			while (run-- && block < blocks) {
+				out = _videoFrameBuffer + (block / bw) * (stride * 4 * doubleY) + (block % bw) * 4;
+				col = mode * 0x01010101;
+				for (i = 0; i < 4 * doubleY; ++i) {
+					out[0] = out[1] = out[2] = out[3] = col;
+					out += stride;
+				}
+				++block;
+			}
+			break;
+		}
+	}
+
+	_fileStream->seek(startPos + frameSize);
+
+	free(_frameData);
+
+	return ++_videoInfo.currentFrame < _videoInfo.frameCount;
+}
+
+void SmackerDecoder::queueCompressedBuffer(byte *buffer, uint32 bufferSize,
+		uint32 unpackedSize, int streamNum) {
+
+	BitStream audioBS(buffer, bufferSize);
+	bool dataPresent = audioBS.getBit();
+
+	if (!dataPresent)
+		return;
+
+	bool isStereo = audioBS.getBit();
+	assert(isStereo == _header.audioInfo[streamNum].isStereo);
+	bool is16Bits = audioBS.getBit();
+	assert(is16Bits == _header.audioInfo[streamNum].is16Bits);
+
+	int numBytes = 1 * (isStereo ? 2 : 1) * (is16Bits ? 2 : 1);
+
+	byte *unpackedBuffer = new byte[unpackedSize];
+	byte *curPointer = unpackedBuffer;
+	uint32 curPos = 0;
+
+	SmallHuffmanTree *audioTrees[4];
+	for (int k = 0; k < numBytes; k++)
+		audioTrees[k] = new SmallHuffmanTree(audioBS);
+
+	// Base values, stored as big endian
+
+	int32 bases[2];
+
+	if (isStereo)
+		bases[1] = (!is16Bits) ?   audioBS.getBits8() :
+		               ((int16) (((audioBS.getBits8() << 8) | audioBS.getBits8())));
+
+	bases[0] = (!is16Bits) ?   audioBS.getBits8() :
+	               ((int16) (((audioBS.getBits8() << 8) | audioBS.getBits8())));
+
+
+	// The bases are the first samples, too
+	for (int i = 0; i < (isStereo ? 2 : 1); i++, curPointer += (is16Bits ? 2 : 1), curPos += (is16Bits ? 2 : 1)) {
+		if (is16Bits)
+			WRITE_BE_UINT16(curPointer, bases[i]);
+		else
+			*curPointer = (bases[i] & 0xFF) ^ 0x80;
+	}
+
+	// Next follow the deltas, which are added to the corresponding base values and
+	// are stored as little endian
+	// We store the unpacked bytes in big endian format
+
+	while (curPos < unpackedSize) {
+		// If the sample is stereo, the data is stored for the left and right channel, respectively
+		// (the exact opposite to the base values)
+		if (!is16Bits) {
+
+			for (int k = 0; k < (isStereo ? 2 : 1); k++) {
+				bases[k] += (int8) ((int16) audioTrees[k]->getCode(audioBS));
+				*curPointer++ = CLIP<int>(bases[k], 0, 255) ^ 0x80;
+				curPos++;
+			}
+
+		} else {
+
+			for (int k = 0; k < (isStereo ? 2 : 1); k++) {
+				bases[k] += (int16) (audioTrees[k * 2]->getCode(audioBS) |
+				                    (audioTrees[k * 2 + 1]->getCode(audioBS) << 8));
+
+				WRITE_BE_UINT16(curPointer, CLIP<int32>(bases[k], -32768, 32767));
+				curPointer += 2;
+				curPos += 2;
+			}
+		}
+
+	}
+
+	for (int k = 0; k < numBytes; k++)
+		delete audioTrees[k];
+
+	_audioStream->queueBuffer(unpackedBuffer, unpackedSize);
+	// unpackedBuffer will be deleted by AppendableAudioStream
+}
+
+void SmackerDecoder::unpackPalette() {
+	uint startPos = _fileStream->pos();
+	uint32 len = 4 * _fileStream->readByte();
+
+	byte *chunk = (byte *)malloc(len);
+	_fileStream->read(&chunk[0], len);
+	byte *p = &chunk[0];
+
+	byte oldPalette[3*256];
+	memcpy(oldPalette, _palette, 3 * 256);
+
+	byte *pal = _palette;
+
+	int sz = 0;
+	byte b0;
+	while (sz < 256) {
+		b0 = *p++;
+		if (b0 & 0x80) {               // if top bit is 1 (0x80 = 10000000)
+			sz += (b0 & 0x7f) + 1;     // get lower 7 bits + 1 (0x7f = 01111111)
+			pal += 3 * ((b0 & 0x7f) + 1);
+		} else if (b0 & 0x40) {        // if top 2 bits are 01 (0x40 = 01000000)
+			byte c = (b0 & 0x3f) + 1;  // get lower 6 bits + 1 (0x3f = 00111111)
+			uint s = 3 * *p++;
+			sz += c;
+
+			while (c--) {
+				*pal++ = oldPalette[s + 0];
+				*pal++ = oldPalette[s + 1];
+				*pal++ = oldPalette[s + 2];
+				s += 3;
+			}
+		} else {                       // top 2 bits are 00
+			sz++;
+			// get the lower 6 bits for each component (0x3f = 00111111)
+			byte b = b0 & 0x3f;
+			byte g = (*p++) & 0x3f;
+			byte r = (*p++) & 0x3f;
+
+			assert(g < 0xc0 && b < 0xc0);
+
+			// upscale to full 8-bit color values by multiplying by 4
+			*pal++ = b * 4;
+			*pal++ = g * 4;
+			*pal++ = r * 4;
+		}
+	}
+
+	_fileStream->seek(startPos + len);
+
+	free(chunk);
+}
+
+} // End of namespace Graphics