diff --git a/core/audio_provider.cpp b/core/audio_provider.cpp
index 2d63a43d8..072f7f62f 100644
--- a/core/audio_provider.cpp
+++ b/core/audio_provider.cpp
@@ -188,7 +188,7 @@ AudioProvider *AudioProvider::GetAudioProvider(wxString filename, AudioDisplay *
 		if (cacheMode == 1) final = new RAMAudioProvider(provider);
 		
 		// Convert to HD
-		//if (cacheMode == 2) final = new HDAudioProvider(provider);
+		if (cacheMode == 2) final = new HDAudioProvider(provider);
 		
 		// Reassign
 		if (final) {
diff --git a/core/audio_provider_avs.cpp b/core/audio_provider_avs.cpp
index fe6cd00f9..ab076bec6 100644
--- a/core/audio_provider_avs.cpp
+++ b/core/audio_provider_avs.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2006, Rodrigo Braz Monteiro
+// Copyright (c) 2005-2006, Rodrigo Braz Monteiro, Fredrik Mellbin
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -45,15 +45,11 @@
 #include "utils.h"
 #include "audio_provider_avs.h"
 #include "options.h"
-#include "main.h"
-#include "dialog_progress.h"
 
 
 //////////////
 // Constructor
 AvisynthAudioProvider::AvisynthAudioProvider(wxString _filename) {
-	type = AUDIO_PROVIDER_NONE;
-
 	filename = _filename;
 
 	try {
@@ -78,12 +74,6 @@ AvisynthAudioProvider::~AvisynthAudioProvider() {
 void AvisynthAudioProvider::Unload() {
 	// Clean up avisynth
 	clip = NULL;
-
-	// Close file
-	if (type == AUDIO_PROVIDER_DISK_CACHE) {
-		file_cache.close();
-		wxRemoveFile(DiskCacheName());
-	}
 }
 
 
@@ -91,7 +81,6 @@ void AvisynthAudioProvider::Unload() {
 // Load audio from avisynth
 void AvisynthAudioProvider::OpenAVSAudio() {
 	// Set variables
-	type = AUDIO_PROVIDER_AVS;
 	AVSValue script;
 
 	// Prepare avisynth
@@ -104,7 +93,9 @@ void AvisynthAudioProvider::OpenAVSAudio() {
 
 		LoadFromClip(script);
 
-	} catch (AvisynthError &err) {
+	}
+	
+	catch (AvisynthError &err) {
 		throw wxString::Format(_T("AviSynth error: %s"), wxString(err.msg,wxConvLocal));
 	}
 }
@@ -150,47 +141,6 @@ void AvisynthAudioProvider::LoadFromClip(AVSValue _clip) {
 }
 
 
-//////////////
-// Disk Cache
-void AvisynthAudioProvider::ConvertToDiskCache(PClip &tempclip) {
-	// Check free space
-	wxLongLong freespace;
-	if (wxGetDiskSpace(DiskCachePath(), NULL, &freespace))
-		if (num_samples * channels * bytes_per_sample > freespace)
-			throw wxString(_T("Not enough free diskspace in "))+DiskCachePath()+wxString(_T(" to cache the audio"));
-
-	// Open output file
-	std::ofstream file;
-	char filename[512];
-	strcpy(filename,DiskCacheName().mb_str(wxConvLocal));
-	file.open(filename,std::ios::binary | std::ios::out | std::ios::trunc);
-
-	// Start progress
-	volatile bool canceled = false;
-	DialogProgress *progress = new DialogProgress(NULL,_T("Load audio"),&canceled,_T("Reading to Hard Disk cache"),0,num_samples);
-	progress->Show();
-
-	// Write to disk
-	int block = 4096;
-	char *temp = new char[block * channels * bytes_per_sample];
-	for (__int64 i=0;i<num_samples && !canceled; i+=block) {
-		if (block+i > num_samples) block = num_samples - i;
-		tempclip->GetAudio(temp,i,block,env);
-		file.write(temp,block * channels * bytes_per_sample);
-		progress->SetProgress(i,num_samples);
-	}
-	file.close();
-	type = AUDIO_PROVIDER_DISK_CACHE;
-
-	// Finish
-	if (!canceled) {
-		progress->Destroy();
-		file_cache.open(filename,std::ios::binary | std::ios::in);
-	}
-	else 
-		throw wxString(_T("Audio loading cancelled by user"));
-}
-
 ////////////////
 // Get filename
 wxString AvisynthAudioProvider::GetFilename() {
@@ -224,33 +174,8 @@ void AvisynthAudioProvider::GetAudio(void *buf, __int64 start, __int64 count) {
 	}
 
 	if (count) {
-		// Disk cache
-		if (type == AUDIO_PROVIDER_DISK_CACHE) {
-			wxMutexLocker disklock(diskmutex);
-			file_cache.seekg(start*bytes_per_sample);
-			file_cache.read((char*)buf,count*bytes_per_sample*channels);
-		}
-
-		// Avisynth
-		else {
-			wxMutexLocker disklock(diskmutex);
-			clip->GetAudio(buf,start,count,env);
-		}
+		clip->GetAudio(buf,start,count,env);
 	}
 }
 
-
-///////////////////////////
-// Get disk cache path
-wxString AvisynthAudioProvider::DiskCachePath() {
-	return AegisubApp::folderName;
-}
-
-
-///////////////////////////
-// Get disk cache filename
-wxString AvisynthAudioProvider::DiskCacheName() {
-	return DiskCachePath() + _T("audio.tmp");
-}
-
 #endif
diff --git a/core/audio_provider_avs.h b/core/audio_provider_avs.h
index db3bca7b7..41cf807a6 100644
--- a/core/audio_provider_avs.h
+++ b/core/audio_provider_avs.h
@@ -42,38 +42,20 @@
 #include <wx/wxprec.h>
 #ifdef __WINDOWS__
 
-#include <fstream>
 #include <time.h>
 #include "avisynth_wrap.h"
 #include "audio_provider.h"
 
 
-//////////////
-// Types enum
-enum AudioProviderType {
-	AUDIO_PROVIDER_NONE,
-	AUDIO_PROVIDER_AVS,
-	AUDIO_PROVIDER_DISK_CACHE
-};
-
-
 ////////////////////////
 // Audio provider class
 class AvisynthAudioProvider : public AudioProvider, public AviSynthWrapper {
 private:
-	wxMutex diskmutex;
-
-	std::ifstream file_cache;
-
-	AudioProviderType type;
 	wxString filename;
 	PClip clip;
 
-	void ConvertToDiskCache(PClip &tempclip);
 	void LoadFromClip(AVSValue clip);
 	void OpenAVSAudio();
-	static wxString DiskCachePath();
-	static wxString DiskCacheName();
 	void SetFile();
 	void Unload();
 
diff --git a/core/audio_provider_hd.cpp b/core/audio_provider_hd.cpp
index d4dea8cb0..538ba438d 100644
--- a/core/audio_provider_hd.cpp
+++ b/core/audio_provider_hd.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2006, Rodrigo Braz Monteiro
+// Copyright (c) 2005-2006, Rodrigo Braz Monteiro, Fredrik Mellbin
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -35,4 +35,112 @@
 
 
 ///////////
-// Headers
\ No newline at end of file
+// Headers
+#include "dialog_progress.h"
+#include "audio_provider_hd.h"
+#include "main.h"
+
+
+///////////////
+// Constructor
+HDAudioProvider::HDAudioProvider(AudioProvider *source) {
+	// Copy parameters
+	bytes_per_sample = source->GetBytesPerSample();
+	num_samples = source->GetNumSamples();
+	channels = source->GetChannels();
+	sample_rate = source->GetSampleRate();
+	filename = source->GetFilename();
+
+	// Check free space
+	wxLongLong freespace;
+	if (wxGetDiskSpace(DiskCachePath(), NULL, &freespace)) {
+		if (num_samples * channels * bytes_per_sample > freespace) {
+			throw wxString(_T("Not enough free diskspace in "))+DiskCachePath()+wxString(_T(" to cache the audio"));
+		}
+	}
+
+	// Open output file
+	std::ofstream file;
+	char filename[512];
+	strcpy(filename,DiskCacheName().mb_str(wxConvLocal));
+	file.open(filename,std::ios::binary | std::ios::out | std::ios::trunc);
+
+	// Start progress
+	volatile bool canceled = false;
+	DialogProgress *progress = new DialogProgress(NULL,_T("Load audio"),&canceled,_T("Reading to Hard Disk cache"),0,num_samples);
+	progress->Show();
+
+	// Write to disk
+	int block = 4096;
+	char *temp = new char[block * channels * bytes_per_sample];
+	for (__int64 i=0;i<num_samples && !canceled; i+=block) {
+		if (block+i > num_samples) block = num_samples - i;
+		source->GetAudio(temp,i,block);
+		file.write(temp,block * channels * bytes_per_sample);
+		progress->SetProgress(i,num_samples);
+	}
+	file.close();
+
+	// Finish
+	if (!canceled) {
+		progress->Destroy();
+		file_cache.open(filename,std::ios::binary | std::ios::in);
+	}
+	else {
+		throw wxString(_T("Audio loading cancelled by user"));
+	}
+}
+
+
+//////////////
+// Destructor
+HDAudioProvider::~HDAudioProvider() {
+	file_cache.close();
+	wxRemoveFile(DiskCacheName());
+}
+
+
+/////////////
+// Get audio
+void HDAudioProvider::GetAudio(void *buf, __int64 start, __int64 count) {
+	// Requested beyond the length of audio
+	if (start+count > num_samples) {
+		__int64 oldcount = count;
+		count = num_samples-start;
+		if (count < 0) count = 0;
+
+		// Fill beyond with zero
+		if (bytes_per_sample == 1) {
+			char *temp = (char *) buf;
+			for (int i=count;i<oldcount;i++) {
+				temp[i] = 0;
+			}
+		}
+		if (bytes_per_sample == 2) {
+			short *temp = (short *) buf;
+			for (int i=count;i<oldcount;i++) {
+				temp[i] = 0;
+			}
+		}
+	}
+
+	if (count) {
+		wxMutexLocker disklock(diskmutex);
+		file_cache.seekg(start*bytes_per_sample);
+		file_cache.read((char*)buf,count*bytes_per_sample*channels);
+	}
+}
+
+
+///////////////////////////
+// Get disk cache path
+wxString HDAudioProvider::DiskCachePath() {
+	return AegisubApp::folderName;
+}
+
+
+///////////////////////////
+// Get disk cache filename
+wxString HDAudioProvider::DiskCacheName() {
+	return DiskCachePath() + _T("audio.tmp");
+}
diff --git a/core/audio_provider_hd.h b/core/audio_provider_hd.h
index e69de29bb..45be3d8fc 100644
--- a/core/audio_provider_hd.h
+++ b/core/audio_provider_hd.h
@@ -0,0 +1,61 @@
+// Copyright (c) 2006, Rodrigo Braz Monteiro
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//   * Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//   * Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//   * Neither the name of the Aegisub Group nor the names of its contributors
+//     may be used to endorse or promote products derived from this software
+//     without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// -----------------------------------------------------------------------------
+//
+// AEGISUB
+//
+// Website: http://aegisub.cellosoft.com
+// Contact: mailto:zeratul@cellosoft.com
+//
+
+
+#pragma once
+
+
+///////////
+// Headers
+#include "audio_provider.h"
+#include <fstream>
+
+
+////////////////////////
+// Audio provider class
+class HDAudioProvider : public AudioProvider {
+private:
+	wxMutex diskmutex;
+	std::ifstream file_cache;
+
+	static wxString DiskCachePath();
+	static wxString DiskCacheName();
+
+public:
+	HDAudioProvider(AudioProvider *source);
+	~HDAudioProvider();
+
+	void GetAudio(void *buf, __int64 start, __int64 count);
+};
diff --git a/core/audio_provider_ram.cpp b/core/audio_provider_ram.cpp
index df9e90e73..68f1763cb 100644
--- a/core/audio_provider_ram.cpp
+++ b/core/audio_provider_ram.cpp
@@ -73,7 +73,7 @@ RAMAudioProvider::RAMAudioProvider(AudioProvider *source) {
 		throw wxString(_T("Couldn't open audio, not enough ram available."));
 	}
 
-	// Copy data
+	// Copy parameters
 	bytes_per_sample = source->GetBytesPerSample();
 	num_samples = source->GetNumSamples();
 	channels = source->GetChannels();