diff --git a/UI/BackgroundAudio.cpp b/UI/BackgroundAudio.cpp
index 261f4af5d2..c87237c0ac 100644
--- a/UI/BackgroundAudio.cpp
+++ b/UI/BackgroundAudio.cpp
@@ -31,10 +31,10 @@ public:
 		u8 at3_extradata[16];
 
 		int num_channels, sample_rate, numFrames, samplesPerSec, avgBytesPerSec, Nothing;
-		if (file_.descend('RIFF')) {
-			file_.readInt(); //get past 'WAVE'
-			if (file_.descend('fmt ')) { //enter the format chunk
-				int temp = file_.readInt();
+		if (file_.Descend('RIFF')) {
+			file_.ReadInt(); //get past 'WAVE'
+			if (file_.Descend('fmt ')) { //enter the format chunk
+				int temp = file_.ReadInt();
 				int format = temp & 0xFFFF;
 				switch (format) {
 				case 0xFFFE:
@@ -50,10 +50,10 @@ public:
 
 				num_channels = temp >> 16;
 
-				samplesPerSec = file_.readInt();
-				avgBytesPerSec = file_.readInt();
+				samplesPerSec = file_.ReadInt();
+				avgBytesPerSec = file_.ReadInt();
 
-				temp = file_.readInt();
+				temp = file_.ReadInt();
 				raw_bytes_per_frame_ = temp & 0xFFFF;
 				Nothing = temp >> 16;
 
@@ -64,41 +64,41 @@ public:
 				if (codec == PSP_CODEC_AT3) {
 					// The first two bytes are actually not a useful part of the extradata.
 					// We already read 16 bytes, so make sure there's enough left.
-					if (file_.getCurrentChunkSize() >= 32) {
-						file_.readData(at3_extradata, 16);
+					if (file_.GetCurrentChunkSize() >= 32) {
+						file_.ReadData(at3_extradata, 16);
 					} else {
 						memset(at3_extradata, 0, sizeof(at3_extradata));
 					}
 				}
-				file_.ascend();
+				file_.Ascend();
 				// ILOG("got fmt data: %i", samplesPerSec);
 			} else {
 				ELOG("Error - no format chunk in wav");
-				file_.ascend();
+				file_.Ascend();
 				return;
 			}
 
-			if (file_.descend('data')) {			//enter the data chunk
-				int numBytes = file_.getCurrentChunkSize();
+			if (file_.Descend('data')) {			//enter the data chunk
+				int numBytes = file_.GetCurrentChunkSize();
 				numFrames = numBytes / raw_bytes_per_frame_;  // numFrames
 
 				raw_data_ = (uint8_t *)malloc(numBytes);
 				raw_data_size_ = numBytes;
 				if (/*raw_bytes_per_frame_ == 280 && */ num_channels == 1 || num_channels == 2) {
-					file_.readData(raw_data_, numBytes);
+					file_.ReadData(raw_data_, numBytes);
 				} else {
 					ELOG("Error - bad blockalign or channels");
 					free(raw_data_);
 					raw_data_ = 0;
 					return;
 				}
-				file_.ascend();
+				file_.Ascend();
 			} else {
 				ELOG("Error - no data chunk in wav");
-				file_.ascend();
+				file_.Ascend();
 				return;
 			}
-			file_.ascend();
+			file_.Ascend();
 		} else {
 			ELOG("Could not descend into RIFF file. Data size=%d", (int32_t)data.size());
 			return;
@@ -153,7 +153,7 @@ public:
 	}
 
 private:
-	ChunkFile file_;
+	RIFFReader file_;
 	uint8_t *raw_data_;
 	int raw_data_size_;
 	int raw_offset_;
diff --git a/ext/native/file/chunk_file.cpp b/ext/native/file/chunk_file.cpp
index 0544417a33..4cd4e5157c 100644
--- a/ext/native/file/chunk_file.cpp
+++ b/ext/native/file/chunk_file.cpp
@@ -3,287 +3,109 @@
 #include "file/zip_read.h"
 #include "file/file_util.h"
 
-//#define CHUNKDEBUG
+#include "Common/Log.h"
 
-ChunkFile::ChunkFile(const char *filename, bool _read) {
-	data=0;
-	fn = filename;
-	numLevels=0;
-	read=_read;
-	pos=0;
-	didFail=false;
-
-	fastMode = read ? true : false;
-
-	if (fastMode) {
-		size_t size;
-		data = (uint8_t *)VFSReadFile(filename, &size);
-		if (!data) {
-			ELOG("Chunkfile fail: %s", filename);
-			didFail = true;
-			return;
-		}
-		eof = (int)size;
-		return;
-	}
-
-	file = openCFile(filename, "wb");
-	if (file) {
-		didFail = false;
-		eof = 0;
-	}	else {
-		didFail = true;
-	}
+inline uint32_t flipID(uint32_t id) {
+	return ((id >> 24) & 0xFF) | ((id >> 8) & 0xFF00) | ((id << 8) & 0xFF0000) | ((id << 24) & 0xFF000000);
 }
 
-ChunkFile::ChunkFile(const uint8_t *read_data, int data_size) {
-	data = new uint8_t[data_size];
-	memcpy(data, read_data, data_size);
-	fastMode = true;
-	numLevels = 0;
-	read = true;
-	pos = 0;
-	didFail = false;
-	eof = data_size;
+RIFFReader::RIFFReader(const uint8_t *data, int dataSize) {
+	data_ = new uint8_t[dataSize];
+	memcpy(data_, data, dataSize);
+	depth_ = 0;
+	pos_ = 0;
+	eof_ = dataSize;
+	fileSize_ = dataSize;
 }
 
-ChunkFile::~ChunkFile() {
-	if (fastMode) {
-		delete[] data;
-	} else {
-		fclose(file);
-	}
+RIFFReader::~RIFFReader() {
+	delete[] data_;
 }
 
-int ChunkFile::readInt() {
-	if (data && pos<eof) {
-		pos += 4;
-		if (fastMode)
-			return *(int *)(data + pos - 4);
-		else {
-			int i;
-			if (fread(&i, 1, 4, file) == 4) {
-				return i;
-			}
-		}
+int RIFFReader::ReadInt() {
+	if (data_ && pos_ < eof_ - 3) {
+		pos_ += 4;
+		return *(int *)(data_ + pos_ - 4);
 	}
 	return 0;
 }
 
-void ChunkFile::writeInt(int i) {
-	fwrite(&i, 1, 4, file);
-	pos += 4;
-}
-
-//let's get into the business
-bool ChunkFile::descend(uint32_t id) {
-	if (numLevels > 30)
+// let's get into the business
+bool RIFFReader::Descend(uint32_t intoId) {
+	if (depth_ > 30)
 		return false;
 
-	id = flipID(id);
-	if (read) {
-		bool found = false;
+	intoId = flipID(intoId);
+	bool found = false;
 
-		//save information to restore after the next Ascend
-		stack[numLevels].parentStartLocation = pos;
-		stack[numLevels].parentEOF = eof;
+	// save information to restore after the next Ascend
+	stack[depth_].parentStartLocation = pos_;
+	stack[depth_].parentEOF = eof_;
 
-		ChunkInfo temp = stack[numLevels];
+	// let's search through children..
+	while (pos_ < eof_) {
+		int id = ReadInt();
+		int length = ReadInt();
+		int startLocation = pos_;
 
-		int firstID = 0;
-		//let's search through children..
-		while(pos<eof) {
-			stack[numLevels].ID = readInt();
-			if (firstID == 0) firstID=stack[numLevels].ID|1;
-			stack[numLevels].length = readInt();
-			stack[numLevels].startLocation = pos;
-
-			if (stack[numLevels].ID == id)
-			{
-				found = true;
-				break;
-			} else {
-				seekTo(pos + stack[numLevels].length); //try next block
-			}
-		} 
-
-		//if we found nothing, return false so the caller can skip this
-		if (!found) {
-#ifdef CHUNKDEBUG
-			ILOG("Couldn't find %c%c%c%c", id, id>>8, id>>16, id>>24);
-#endif
-			stack[numLevels]=temp;
-			seekTo(stack[numLevels].parentStartLocation);
+		if (pos_ + length > fileSize_) {
+			ERROR_LOG(SYSTEM, "Block extends outside of RIFF file - failing descend");
+			pos_ = stack[depth_].parentStartLocation;
 			return false;
 		}
 
-		//descend into it
-		//pos was set inside the loop above
-		eof = stack[numLevels].startLocation + stack[numLevels].length;
-		numLevels++;
-#ifdef CHUNKDEBUG
-		ILOG("Descended into %c%c%c%c", id, id>>8, id>>16, id>>24);
-#endif
-		return true;
-	} else {
-#ifndef DEMO_VERSION	//if this is missing.. heheh
-		//write a chunk id, and prepare for filling in length later
-		writeInt(id);
-		writeInt(0); //will be filled in by Ascend
-		stack[numLevels].startLocation=pos;
-		numLevels++;
-		return true;
-#else
-		return true;
-#endif
-	}
-}
-
-void ChunkFile::seekTo(int _pos) {
-	if (!fastMode) {
-		fseek(file, 0, SEEK_SET);
-	}
-	pos = _pos;
-}
-
-//let's ascend out
-void ChunkFile::ascend() {
-	if (read) {
-		//ascend, and restore information
-		numLevels--;
-		seekTo(stack[numLevels].parentStartLocation);
-		eof = stack[numLevels].parentEOF;
-#ifdef CHUNKDEBUG
-		int id = stack[numLevels].ID;
-		ILOG("Ascended out of %c%c%c%c", id, id>>8, id>>16, id>>24);
-#endif
+		if (id == intoId) {
+			stack[depth_].ID = intoId;
+			stack[depth_].length = length;
+			stack[depth_].startLocation = startLocation;
+			found = true;
+			break;
 		} else {
-		numLevels--;
-		//now fill in the written length automatically
-		int posNow = pos;
-		seekTo(stack[numLevels].startLocation - 4);
-		writeInt(posNow-stack[numLevels].startLocation);
-		seekTo(posNow);
-	}
-}
-
-//read a block
-void ChunkFile::readData(void *what, int count) {
-	if (fastMode) {
-		memcpy(what, data + pos, count);
-	} else {
-		if (fread(what, 1, count, file) != (size_t)count) {
-			ELOG("Failed to read complete %d bytes", count);
-		}
-	}
-
-	pos+=count;
-	count &= 3;
-	if (count) {
-		count=4-count;
-		if (!fastMode) {
-			if (fseek(file, count, SEEK_CUR) != 0) {
-				ELOG("Missing padding");
+			if (length > 0) {
+				pos_ += length; // try next block
+			} else {
+				ERROR_LOG(SYSTEM, "Bad data in RIFF file : block length %d. Not descending.", length);
+				pos_ = stack[depth_].parentStartLocation;
+				return false;
 			}
 		}
-		pos+=count;
+	}
+
+	// if we found nothing, return false so the caller can skip this
+	if (!found) {
+		pos_ = stack[depth_].parentStartLocation;
+		return false;
+	}
+
+	// descend into it
+	// pos was set inside the loop above
+	eof_ = stack[depth_].startLocation + stack[depth_].length;
+	depth_++;
+	return true;
+}
+
+// let's ascend out
+void RIFFReader::Ascend() {
+	// ascend, and restore information
+	depth_--;
+	pos_ = stack[depth_].parentStartLocation;
+	eof_ = stack[depth_].parentEOF;
+}
+
+// read a block
+void RIFFReader::ReadData(void *what, int count) {
+	memcpy(what, data_ + pos_, count);
+	pos_ += count;
+	count &= 3;
+	if (count) {
+		count = 4 - count;
+		pos_ += count;
 	}
 }
 
-//write a block
-void ChunkFile::writeData(const void *what, int count) {
-	fwrite(what, 1, count, file);
-	pos+=count;
-	char temp[5]={0,0,0,0,0};
-	count &= 3; 
-	if (count)
-	{
-		count=4-count;
-		fwrite(temp, 1, count, file);
-		pos+=count;
-	}
-}
-
-/*
-void ChunkFile::writeWString(String str) {
-	wchar_t *text;
-	int len=str.length();
-#ifdef UNICODE
-#error
-	text = str.getPointer();
-#else
-	text = new wchar_t[len+1];
-	str.toUnicode(text);
-#endif
-	writeInt(len);
-	writeData((char *)text, len * sizeof(wchar_t));
-#ifndef UNICODE
-	delete [] text;
-#endif
-}
-*/
-
-// Takes utf-8
-void ChunkFile::writeWString(const std::string &str) {
-	unsigned short *text;
-	int len = (int)str.length();
-	text = new unsigned short[len+1];
-	for (int i = 0; i < len; i++)
-		text[i] = str[i];
-	text[len]=0;
-	writeInt(len);
-	writeData((char *)text, len * sizeof(unsigned short));
-	delete [] text;
-}
-
-static void toUnicode(const std::string &str, uint16_t *t) {
-	for (size_t i = 0; i < str.size(); i++) {
-		*t++ = str[i];
-	}
-	*t++ = '\0';
-}
-
-static std::string fromUnicode(const uint16_t *src, int len) {
-	std::string str;
-	str.resize(len);
-	for (int i = 0; i < len; i++) {
-		str[i] = src[i] > 255 ? ' ' : src[i];
-	}
-	return str;
-}
-
-std::string ChunkFile::readWString() {
-	int len=readInt();
-	uint16_t *text = new uint16_t[len+1];
-	readData((char *)text, len*sizeof(uint16_t));
-	text[len] = 0;
-	std::string temp = fromUnicode(text, len);
-	delete [] text;
-	return temp;
-}
-
-void ChunkFile::writeString(const std::string &str) {
-	uint16_t *text;
-	int len = (int)str.size();
-	text=new uint16_t[len+1];
-	toUnicode(str, text);
-	writeInt(len);
-	writeData((char *)text,len*sizeof(uint16_t));
-	delete [] text;
-}
-
-std::string ChunkFile::readString() {
-	int len=readInt();
-	uint16_t *text = new uint16_t[len+1];
-	readData((char *)text,len*sizeof(uint16_t));
-	text[len]=0;
-	std::string temp = fromUnicode(text, len);
-	delete [] text;
-	return temp;
-}
-int ChunkFile::getCurrentChunkSize() {
-	if (numLevels)
-		return stack[numLevels-1].length;
+int RIFFReader::GetCurrentChunkSize() {
+	if (depth_)
+		return stack[depth_ - 1].length;
 	else
 		return 0;
 }
diff --git a/ext/native/file/chunk_file.h b/ext/native/file/chunk_file.h
index f1e9d8f3ee..18d8a80e8b 100644
--- a/ext/native/file/chunk_file.h
+++ b/ext/native/file/chunk_file.h
@@ -10,62 +10,34 @@
 // otherwise the scheme breaks.
 
 #include <string>
-#include <stdio.h>
+#include <cstdio>
+#include <cstdint>
 
-#include "base/basictypes.h"
-
-inline uint32_t flipID(uint32_t id) {
-	return ((id>>24)&0xFF) | ((id>>8)&0xFF00) | ((id<<8)&0xFF0000) | ((id<<24)&0xFF000000);
-}
-
-class ChunkFile {
+class RIFFReader {
 public:
-	ChunkFile(const char *filename, bool _read);
-	ChunkFile(const uint8_t *read_data, int data_size);
+	RIFFReader(const uint8_t *data, int dataSize);
+	~RIFFReader();
 
-	~ChunkFile();
+	bool Descend(uint32_t id);
+	void Ascend();
 
-	bool descend(uint32_t id);
-	void ascend();
+	int ReadInt();
+	void ReadData(void *data, int count);
 
-	int	readInt();
-	void readInt(int &i) {i = readInt();}
-	void readData(void *data, int count);
-	// String readWString();
-	std::string readWString();
-
-	void writeString(const std::string &str);
-	std::string readString();
-
-	void writeInt(int i);
-	//void writeWString(String str);
-	void writeWString(const std::string &str);
-	void writeData(const void *data, int count);
-
-	int getCurrentChunkSize();
-	bool failed() const { return didFail; }
-	std::string filename() const { return fn; }
+	int GetCurrentChunkSize();
 
 private:
-	std::string fn;
-	FILE *file;
 	struct ChunkInfo {
 		int startLocation;
 		int parentStartLocation;
 		int parentEOF;
-		unsigned int ID;
+		uint32_t ID;
 		int length;
 	};
 	ChunkInfo stack[32];
-	int numLevels;
-
-	uint8_t *data;
-	int pos;
-	int eof;
-	bool fastMode;
-	bool read;
-	bool didFail;
-
-	void seekTo(int _pos);
-	int getPos() const {return pos;}
+	uint8_t *data_;
+	int pos_ = 0;
+	int eof_ = 0;  // really end of current block
+	int depth_ = 0;
+	int fileSize_ = 0;
 };