diff --git a/stepmania/src/RageSoundReader_MP3.cpp b/stepmania/src/RageSoundReader_MP3.cpp
index c1d100c68c..0eee1e74ac 100644
--- a/stepmania/src/RageSoundReader_MP3.cpp
+++ b/stepmania/src/RageSoundReader_MP3.cpp
@@ -998,6 +998,14 @@ int RageSoundReader_MP3::SetPosition_Fast( int ms )
 	return SetPosition_estimate( ms );
 }
 
+// XXX: untested
+int RageSoundReader_MP3::GetNextStreamFrame() const
+{
+	mad_timer_t now( mad->Timer );
+	mad_timer_multiply( &now, mad->Frame.header.samplerate );
+	return now.seconds;
+}
+
 int RageSoundReader_MP3::GetLengthInternal( bool fast )
 {
 	if( mad->has_xing && mad->length != -1 )
diff --git a/stepmania/src/RageSoundReader_MP3.h b/stepmania/src/RageSoundReader_MP3.h
index afa4477487..2910d95cf3 100644
--- a/stepmania/src/RageSoundReader_MP3.h
+++ b/stepmania/src/RageSoundReader_MP3.h
@@ -19,6 +19,7 @@ public:
 	int SetPosition_Fast(int ms);
 	int Read(char *buf, unsigned len);
 	int GetSampleRate() const { return SampleRate; }
+	int GetNextStreamFrame() const;
 
 	RageSoundReader_MP3();
 	~RageSoundReader_MP3();
diff --git a/stepmania/src/RageSoundReader_Vorbisfile.cpp b/stepmania/src/RageSoundReader_Vorbisfile.cpp
index cf83f79fc5..dc357a5422 100644
--- a/stepmania/src/RageSoundReader_Vorbisfile.cpp
+++ b/stepmania/src/RageSoundReader_Vorbisfile.cpp
@@ -255,6 +255,14 @@ int RageSoundReader_Vorbisfile::GetSampleRate() const
 	return vi->rate;
 }
 
+int RageSoundReader_Vorbisfile::GetNextStreamFrame() const
+{
+	ASSERT(vf);
+
+	int iFrame = ov_pcm_tell( vf );
+	return iFrame;
+}
+
 RageSoundReader_Vorbisfile::RageSoundReader_Vorbisfile()
 {
 	vf = NULL;
diff --git a/stepmania/src/RageSoundReader_Vorbisfile.h b/stepmania/src/RageSoundReader_Vorbisfile.h
index 8f2f677938..74c2d45a3c 100644
--- a/stepmania/src/RageSoundReader_Vorbisfile.h
+++ b/stepmania/src/RageSoundReader_Vorbisfile.h
@@ -21,6 +21,7 @@ public:
 	int Read(char *buf, unsigned len);
 	int GetSampleRate() const;
 	unsigned GetNumChannels() const { return channels; }
+	int GetNextStreamFrame() const;
 	RageSoundReader_Vorbisfile();
 	~RageSoundReader_Vorbisfile();
 	RageSoundReader_Vorbisfile *Copy() const;
diff --git a/stepmania/src/RageSoundReader_WAV.cpp b/stepmania/src/RageSoundReader_WAV.cpp
index f627ef4a55..efd6fad6b5 100644
--- a/stepmania/src/RageSoundReader_WAV.cpp
+++ b/stepmania/src/RageSoundReader_WAV.cpp
@@ -46,6 +46,7 @@ struct WavReader
 	virtual int GetLength() const = 0;
 	virtual bool Init() = 0;
 	virtual int SetPosition( int iMS ) = 0;
+	virtual int GetNextStreamFrame() const = 0;
 	RString GetError() const { return m_sError; }
 
 protected:
@@ -115,6 +116,14 @@ struct WavReaderPCM: public WavReader
 		m_File.Seek( iByte+m_WavData.m_iDataChunkPos );
 		return int((int64_t(iByte) * 1000) / iBytesPerSec);
 	}
+
+	// XXX: untested
+	int GetNextStreamFrame() const
+	{
+		int iByte = m_File.Tell() - m_WavData.m_iDataChunkPos;
+		int iFrame = iByte / (m_WavData.m_iChannels * m_WavData.m_iBitsPerSample / 8);
+		return iFrame;
+	}
 };
 
 struct WavReaderADPCM: public WavReader
@@ -352,6 +361,20 @@ public:
 
 		return iMS;
 	}
+
+	// XXX: untested
+	int GetNextStreamFrame() const
+	{
+		int iByte = m_File.Tell() - m_WavData.m_iDataChunkPos;
+		int iBlock = iByte / m_WavData.m_iBlockAlign;
+		int iFrame = iBlock * m_iFramesPerBlock;
+
+		int iBufferRemainingBytes = m_iBufferAvail - m_iBufferUsed;
+		int iBufferRemainingFrames = iBufferRemainingBytes / (m_WavData.m_iChannels * sizeof(int16_t));
+		iFrame -= iBufferRemainingFrames;
+
+		return iFrame;
+	}
 };
 
 RString ReadString( RageFile &f, int iSize, RString &sError )
@@ -500,6 +523,12 @@ int RageSoundReader_WAV::SetPosition( int ms )
 	return m_pImpl->SetPosition( ms );
 }
 
+int RageSoundReader_WAV::GetNextStreamFrame() const
+{
+	ASSERT( m_pImpl != NULL );
+	return m_pImpl->GetNextStreamFrame();
+}
+
 int RageSoundReader_WAV::Read( char *buf, unsigned len )
 {
 	ASSERT( m_pImpl != NULL );
diff --git a/stepmania/src/RageSoundReader_WAV.h b/stepmania/src/RageSoundReader_WAV.h
index 3aaec677e1..d5c871e4e9 100644
--- a/stepmania/src/RageSoundReader_WAV.h
+++ b/stepmania/src/RageSoundReader_WAV.h
@@ -19,6 +19,7 @@ public:
 	int Read( char *buf, unsigned len );
 	int GetSampleRate() const { return m_WavData.m_iSampleRate; }
 	unsigned GetNumChannels() const { return m_WavData.m_iChannels; }
+	int GetNextStreamFrame() const;
 	RageSoundReader_WAV();
 	~RageSoundReader_WAV();
 	RageSoundReader_WAV( const RageSoundReader_WAV & ); /* not defined; don't use */