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Switch to floating-point sound internally.

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This allows us to change the volume of sounds in filters ("volume",
"fade" properties) without quantizing the audio prematurely.  Previously,
we had a hack to apply volume changes as a mixing-time step.  This
can be done at any point in the filter chain now.

This also means we only need to worry about clipping at the very
last mixing step, instead of at every place we change sound.

Dithering for 16-bit audio and more intelligent gain control
is possible, as we have full-resolution, unclipped sound at the
mixing phase.

We support high resolution source sounds; both Vorbis and MAD
supply more than 16 bits.

Several filters, such as resampling, are easier to implement as
floats; these no longer need to convert back and forth.

Negatives:
 - More memory use.  The main case of this is in RageSoundReader_Preload,
which will be fixed: we can preload in 16-bit without losing most of the
above.
 - Some extra overhead for accessing more memory.
This commit is contained in:
Glenn Maynard
2007-01-27 07:14:58 +00:00
parent cc8182fb7e
commit 1bd5513698
33 changed files with 185 additions and 150 deletions
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stepmania/src/RageSoundReader_SpeedChange.cpp
+17 -17
View File
@@ -44,7 +44,7 @@ void RageSoundReader_SpeedChange::Reset()
m_fErrorFrames = 0;
}
static int FindClosestMatch( const int16_t *pBuffer, int iBufferSize, const int16_t *pCorrelateBuffer, int iCorrelateBufferSize, int iStride )
static int FindClosestMatch( const float *pBuffer, int iBufferSize, const float *pCorrelateBuffer, int iCorrelateBufferSize, int iStride )
{
if( iBufferSize <= iCorrelateBufferSize )
return 0;
@@ -55,20 +55,20 @@ static int FindClosestMatch( const int16_t *pBuffer, int iBufferSize, const int1
int iBufferDistanceToSearch = iBufferSize - iCorrelateBufferSize;
int iBestOffset = 0;
int iBestScore = 0;
int fBestScore = 0;
for( int i = 0; i < iBufferDistanceToSearch; i += iStride )
{
int iScore = 0;
const int16_t *pFrames = pBuffer + i;
float fScore = 0;
const float *pFrames = pBuffer + i;
for( int j = 0; j < iCorrelateBufferSize; j += iStride )
{
int iDiff = pFrames[j] - pCorrelateBuffer[j];
iScore += abs(iDiff);
float fDiff = pFrames[j] - pCorrelateBuffer[j];
fScore += fabsf(fDiff);
}
if( i == 0 || iScore < iBestScore )
if( i == 0 || fScore < fBestScore )
{
iBestScore = iScore;
fBestScore = fScore;
iBestOffset = i;
}
}
@@ -85,11 +85,11 @@ int RageSoundReader_SpeedChange::FillData( int iMaxFrames )
while( iMaxFrames > 0 )
{
int iFramesToRead = iMaxFrames - m_iDataBufferAvailFrames;
int iBytesToRead = iFramesToRead * m_Channels.size() * sizeof(int16_t);
int iBytesToRead = iFramesToRead * m_Channels.size() * sizeof(float);
if( iBytesToRead <= 0 )
return m_iDataBufferAvailFrames;
int16_t *pTempBuffer = (int16_t *) alloca( iBytesToRead );
float *pTempBuffer = (float *) alloca( iBytesToRead );
int iGotFrames = m_pSource->Read( pTempBuffer, iFramesToRead );
if( iGotFrames < 0 )
{
@@ -105,8 +105,8 @@ int RageSoundReader_SpeedChange::FillData( int iMaxFrames )
if( (int) c.m_DataBuffer.size() < iMaxFrames )
c.m_DataBuffer.resize( iMaxFrames );
const int16_t *pIn = pTempBuffer + i;
int16_t *pOut = &c.m_DataBuffer[m_iDataBufferAvailFrames];
const float *pIn = pTempBuffer + i;
float *pOut = &c.m_DataBuffer[m_iDataBufferAvailFrames];
for( int j = 0; j < iGotFrames; ++j )
{
*pOut = *pIn;
@@ -133,7 +133,7 @@ void RageSoundReader_SpeedChange::EraseData( int iFramesToDelete )
{
ChannelInfo &c = m_Channels[i];
if( iFramesToMove )
memmove( &c.m_DataBuffer[0], &c.m_DataBuffer[iFramesToDelete], iFramesToMove * sizeof(int16_t) );
memmove( &c.m_DataBuffer[0], &c.m_DataBuffer[iFramesToDelete], iFramesToMove * sizeof(float) );
ASSERT( c.m_iCorrelatedPos >= iFramesToDelete );
c.m_iCorrelatedPos -= iFramesToDelete;
}
@@ -233,7 +233,7 @@ int RageSoundReader_SpeedChange::GetCursorAvail() const
return iCursorAvail;
}
int RageSoundReader_SpeedChange::Read( int16_t *pBuf, int iFrames )
int RageSoundReader_SpeedChange::Read( float *pBuf, int iFrames )
{
while( 1 )
{
@@ -269,9 +269,9 @@ int RageSoundReader_SpeedChange::Read( int16_t *pBuf, int iFrames )
for( size_t i = 0; i < m_Channels.size(); ++i )
{
ChannelInfo &c = m_Channels[i];
int i1 = c.m_DataBuffer[c.m_iCorrelatedPos+m_iPos];
int i2 = c.m_DataBuffer[c.m_iLastCorrelatedPos+m_iPos];
*pBuf++ = int16_t( SCALE( m_iPos, 0, iWindowSizeFrames, i2, i1 ) );
float i1 = c.m_DataBuffer[c.m_iCorrelatedPos+m_iPos];
float i2 = c.m_DataBuffer[c.m_iLastCorrelatedPos+m_iPos];
*pBuf++ = SCALE( m_iPos, 0, iWindowSizeFrames, i2, i1 );
}
++m_iPos;