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exact ratio (no fixed-point granularity)

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This commit is contained in:
Glenn Maynard
2006-12-27 07:51:57 +00:00
parent 8f9885c229
commit 9f577de2e5
2 changed files with 28 additions and 24 deletions
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stepmania/src/RageSoundReader_SpeedChange.cpp
+25 -19
View File
@@ -10,23 +10,24 @@ RageSoundReader_SpeedChange::RageSoundReader_SpeedChange( RageSoundReader *pSour
RageSoundReader_Filter( pSource )
{
m_Channels.resize( pSource->GetNumChannels() );
SetSpeedRatio( 1.3f );
m_fSpeedRatio = m_fTrailingSpeedRatio = 1.0f;
SetSpeedRatio( 1.0f );
Reset();
}
void RageSoundReader_SpeedChange::SetSpeedRatio( float fRatio )
{
fSpeed = fRatio;
m_fSpeedRatio = fRatio;
m_iDeltaFrames = lrintf( GetWindowSizeFrames() * fRatio );
/* If we havn't read any data yet, put the new delta into effect immediately. */
if( m_iDataBufferAvailFrames == 0 )
m_iTrailingDeltaFrames = m_iDeltaFrames;
m_fTrailingSpeedRatio = m_fSpeedRatio;
}
float RageSoundReader_SpeedChange::GetRatio() const
{
return float(m_iDeltaFrames) / GetWindowSizeFrames();
return m_fSpeedRatio;
}
int RageSoundReader_SpeedChange::GetWindowSizeFrames() const
@@ -34,14 +35,9 @@ int RageSoundReader_SpeedChange::GetWindowSizeFrames() const
return (WINDOW_SIZE_MS * GetSampleRate()) / 1000;
}
float RageSoundReader_SpeedChange::GetTrailingRatio() const
{
return float(m_iTrailingDeltaFrames) / GetWindowSizeFrames();
}
void RageSoundReader_SpeedChange::Reset()
{
m_iTrailingDeltaFrames = m_iDeltaFrames;
m_fTrailingSpeedRatio = m_fSpeedRatio;
m_iDataBufferAvailFrames = 0;
for( size_t i = 0; i < m_Channels.size(); ++i )
{
@@ -51,6 +47,7 @@ void RageSoundReader_SpeedChange::Reset()
}
m_iUncorrelatedPos = 0;
m_iPos = 0;
m_fErrorFrames = 0;
}
static int FindClosestMatch( const int16_t *pBuffer, int iBufferSize, const int16_t *pCorrelateBuffer, int iCorrelateBufferSize, int iStride )
@@ -164,13 +161,22 @@ int RageSoundReader_SpeedChange::Step()
m_Channels[i].m_iCorrelatedPos += m_iPos;
}
/* Advance m_iUncorrelatedPos to the position we'd prefer to continue playing from. */
m_iUncorrelatedPos += m_iTrailingDeltaFrames;
/* Advance m_iUncorrelatedPos to the position we'd prefer to continue playing from.
* This rounds the position, making the ratio imprecise. Record the amount of
* error introduced here. If we want to advance by 2.3 frames, we'll advance
* by 2.0 frames, and advance by 0.3 more the next time around. */
float fAdvanceFrames = GetWindowSizeFrames() * m_fTrailingSpeedRatio;
fAdvanceFrames += m_fErrorFrames;
int iTrailingDeltaFrames = lrintf( fAdvanceFrames );
m_fErrorFrames = fAdvanceFrames - iTrailingDeltaFrames;
m_iUncorrelatedPos += iTrailingDeltaFrames;
m_iPos = 0;
}
m_iTrailingDeltaFrames = m_iDeltaFrames;
/* Update m_fTrailingSpeedRatio. Do this after advancing m_iUncorrelatedPos,
* so changes to m_iUncorrelatedPos line up with GetNextSourceFrame. */
m_fTrailingSpeedRatio = m_fSpeedRatio;
/* We don't need any data before the earlier of m_iUncorrelatedPos or m_iCorrelatedPos. */
int iToDelete = m_iUncorrelatedPos;
@@ -242,7 +248,7 @@ int RageSoundReader_SpeedChange::Read( char *buf, int iFrames )
// m_iDataBufferAvailFrames-m_iCorrelatedPos < GetWindowSizeFrames when flushing
int iCursorAvail = GetCursorAvail();
if( iCursorAvail == 0 && m_iTrailingDeltaFrames == m_iDeltaFrames && GetWindowSizeFrames() == m_iDeltaFrames )
if( iCursorAvail == 0 && m_fTrailingSpeedRatio == m_fSpeedRatio && GetWindowSizeFrames() == m_iDeltaFrames )
{
/* Fast path: the buffer is empty, and we're not scaling the audio. Read directly
* into the output buffer, to eliminate memory and copying overhead. */
@@ -291,8 +297,8 @@ int RageSoundReader_SpeedChange::SetPosition( int iFrame )
{
Reset();
int64_t iScaled = (int64_t(iFrame) * GetWindowSizeFrames()) / m_iDeltaFrames;
iFrame = (int) iScaled;
// int64_t iScaled = int64_t(iFrame) / m_fSpeedRatio;
// iFrame = (int) iScaled;
return RageSoundReader_Filter::SetPosition( iFrame );
}
@@ -310,7 +316,7 @@ bool RageSoundReader_SpeedChange::SetProperty( const RString &sProperty, float f
int RageSoundReader_SpeedChange::GetNextSourceFrame() const
{
float fRatio = GetTrailingRatio();
float fRatio = m_fTrailingSpeedRatio; //GetTrailingRatio();
int iSourceFrame = RageSoundReader_Filter::GetNextSourceFrame();
int iPos = lrintf(m_iPos * fRatio);
@@ -326,9 +332,9 @@ float RageSoundReader_SpeedChange::GetStreamToSourceRatio() const
* become the real ratio on the next read. Otherwise, we'll continue using
* our old ratio for a bit longer. */
if( GetCursorAvail() == 0 )
return GetRatio() * RageSoundReader_Filter::GetStreamToSourceRatio();
return m_fSpeedRatio * RageSoundReader_Filter::GetStreamToSourceRatio();
else
return GetTrailingRatio() * RageSoundReader_Filter::GetStreamToSourceRatio();
return m_fTrailingSpeedRatio * RageSoundReader_Filter::GetStreamToSourceRatio();
}
/*
stepmania/src/RageSoundReader_SpeedChange.h
+3 -5
View File
@@ -32,9 +32,6 @@ protected:
int Step();
void Reset();
/* Get the ratio currently being used. */
float GetTrailingRatio() const;
int GetCursorAvail() const;
int GetWindowSizeFrames() const;
@@ -52,9 +49,10 @@ protected:
int m_iUncorrelatedPos;
int m_iPos;
float fSpeed;
float m_fSpeedRatio;
float m_fTrailingSpeedRatio;
int m_iDeltaFrames;
int m_iTrailingDeltaFrames;
float m_fErrorFrames;
};
#endif