245 lines
10 KiB
C++
245 lines
10 KiB
C++
/* $Header: /cvs/root/winamp/vlb/prediction.cpp,v 1.1 2009/04/28 20:21:10 audiodsp Exp $ */
|
|
|
|
#ifdef MAIN_PROFILE
|
|
|
|
/***************************************************************************\
|
|
*
|
|
* Copyright 2000-2002 Dolby Laboratories, Inc. All Rights
|
|
* Reserved. Do not copy. Do not distribute.
|
|
* Confidential information.
|
|
*
|
|
* (C) copyright Fraunhofer - IIS (1998)
|
|
* All Rights Reserved
|
|
*
|
|
* filename: prediction.cpp
|
|
* project : MPEG-2 AAC Decoder
|
|
* contents/description: prediction tool
|
|
*
|
|
\***************************************************************************/
|
|
|
|
#include "prediction.h"
|
|
#include "channelinfo.h"
|
|
#include "block.h"
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
// CQuantizedFloat
|
|
|
|
const float CPrediction::CQuantizedFloat::m_Mantissa [128] =
|
|
{
|
|
0.953125F, 0.945313F, 0.937500F, 0.929688F, 0.925781F, 0.917969F, 0.910156F, 0.902344F,
|
|
0.898438F, 0.890625F, 0.882813F, 0.878906F, 0.871094F, 0.867188F, 0.859375F, 0.851563F,
|
|
0.847656F, 0.839844F, 0.835938F, 0.828125F, 0.824219F, 0.820313F, 0.812500F, 0.808594F,
|
|
0.800781F, 0.796875F, 0.792969F, 0.785156F, 0.781250F, 0.777344F, 0.773438F, 0.765625F,
|
|
0.761719F, 0.757813F, 0.753906F, 0.750000F, 0.742188F, 0.738281F, 0.734375F, 0.730469F,
|
|
0.726563F, 0.722656F, 0.718750F, 0.714844F, 0.710938F, 0.707031F, 0.699219F, 0.695313F,
|
|
0.691406F, 0.687500F, 0.683594F, 0.679688F, 0.679688F, 0.675781F, 0.671875F, 0.667969F,
|
|
0.664063F, 0.660156F, 0.656250F, 0.652344F, 0.648438F, 0.644531F, 0.640625F, 0.640625F,
|
|
0.636719F, 0.632813F, 0.628906F, 0.625000F, 0.621094F, 0.621094F, 0.617188F, 0.613281F,
|
|
0.609375F, 0.605469F, 0.605469F, 0.601563F, 0.597656F, 0.593750F, 0.593750F, 0.589844F,
|
|
0.585938F, 0.582031F, 0.582031F, 0.578125F, 0.574219F, 0.574219F, 0.570313F, 0.566406F,
|
|
0.566406F, 0.562500F, 0.558594F, 0.558594F, 0.554688F, 0.550781F, 0.550781F, 0.546875F,
|
|
0.542969F, 0.542969F, 0.539063F, 0.539063F, 0.535156F, 0.531250F, 0.531250F, 0.527344F,
|
|
0.527344F, 0.523438F, 0.519531F, 0.519531F, 0.515625F, 0.515625F, 0.511719F, 0.511719F,
|
|
0.507813F, 0.507813F, 0.503906F, 0.503906F, 0.500000F, 0.498047F, 0.496094F, 0.494141F,
|
|
0.492188F, 0.490234F, 0.488281F, 0.486328F, 0.484375F, 0.482422F, 0.480469F, 0.478516F
|
|
} ;
|
|
|
|
const float CPrediction::CQuantizedFloat::m_Exponent [256] =
|
|
{
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F, 0.000000e+000F,
|
|
5.000000e-001F, 2.500000e-001F, 1.250000e-001F, 6.250000e-002F, 3.125000e-002F, 1.562500e-002F, 7.812500e-003F, 3.906250e-003F,
|
|
1.953125e-003F, 9.765625e-004F, 4.882813e-004F, 2.441406e-004F, 1.220703e-004F, 6.103516e-005F, 3.051758e-005F, 1.525879e-005F,
|
|
7.629395e-006F, 3.814697e-006F, 1.907349e-006F, 9.536743e-007F, 4.768372e-007F, 2.384186e-007F, 1.192093e-007F, 5.960464e-008F,
|
|
2.980232e-008F, 1.490116e-008F, 7.450581e-009F, 3.725290e-009F, 1.862645e-009F, 9.313226e-010F, 4.656613e-010F, 2.328306e-010F,
|
|
1.164153e-010F, 5.820766e-011F, 2.910383e-011F, 1.455192e-011F, 7.275958e-012F, 3.637979e-012F, 1.818989e-012F, 9.094947e-013F,
|
|
4.547474e-013F, 2.273737e-013F, 1.136868e-013F, 5.684342e-014F, 2.842171e-014F, 1.421085e-014F, 7.105427e-015F, 3.552714e-015F,
|
|
1.776357e-015F, 8.881784e-016F, 4.440892e-016F, 2.220446e-016F, 1.110223e-016F, 5.551115e-017F, 2.775558e-017F, 1.387779e-017F,
|
|
6.938894e-018F, 3.469447e-018F, 1.734723e-018F, 8.673617e-019F, 4.336809e-019F, 2.168404e-019F, 1.084202e-019F, 5.421011e-020F,
|
|
2.710505e-020F, 1.355253e-020F, 6.776264e-021F, 3.388132e-021F, 1.694066e-021F, 8.470329e-022F, 4.235165e-022F, 2.117582e-022F,
|
|
1.058791e-022F, 5.293956e-023F, 2.646978e-023F, 1.323489e-023F, 6.617445e-024F, 3.308722e-024F, 1.654361e-024F, 8.271806e-025F,
|
|
4.135903e-025F, 2.067952e-025F, 1.033976e-025F, 5.169879e-026F, 2.584939e-026F, 1.292470e-026F, 6.462349e-027F, 3.231174e-027F,
|
|
1.615587e-027F, 8.077936e-028F, 4.038968e-028F, 2.019484e-028F, 1.009742e-028F, 5.048710e-029F, 2.524355e-029F, 1.262177e-029F,
|
|
6.310887e-030F, 3.155444e-030F, 1.577722e-030F, 7.888609e-031F, 3.944305e-031F, 1.972152e-031F, 9.860761e-032F, 4.930381e-032F,
|
|
2.465190e-032F, 1.232595e-032F, 6.162976e-033F, 3.081488e-033F, 1.540744e-033F, 7.703720e-034F, 3.851860e-034F, 1.925930e-034F,
|
|
9.629650e-035F, 4.814825e-035F, 2.407412e-035F, 1.203706e-035F, 6.018531e-036F, 3.009266e-036F, 1.504633e-036F, 7.523164e-037F,
|
|
3.761582e-037F, 1.880791e-037F, 9.403955e-038F, 4.701977e-038F, 2.350989e-038F, 1.175494e-038F, 5.877472e-039F, 0.000000e+000F
|
|
} ;
|
|
|
|
float CPrediction::CQuantizedFloat::GetBDivVar (void)
|
|
{
|
|
// description: compute division of B/VAR by means of two look up tables
|
|
// returns: single precision float (B/VAR)
|
|
|
|
unsigned int mntInd = m_Value & 0x007F0000 ; // extract the 7-bit mantissa index
|
|
unsigned int expInd = m_Value & 0x7F800000 ; // extract the 8-bit exponent index
|
|
|
|
return m_Mantissa [mntInd >> 16] * m_Exponent [expInd >> 23] ;
|
|
}
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
// CPredictionState
|
|
|
|
float CPrediction::CPredictionState::FloatRoundInfinity (float x)
|
|
{
|
|
// description: rounds 32 bit single precision number to 16 bit precision
|
|
// float towards infinity (non IEEE comform)
|
|
// returns: rounded float
|
|
// input: 32 bit single precision float
|
|
|
|
unsigned int t = DWORDCAST(x) ;
|
|
unsigned int flag = t & 0x8000 ;
|
|
|
|
t &= 0xFFFF0000L ; // zero out bits below LSB
|
|
x = FLOATCAST(t) ;
|
|
|
|
// if the below-LSB part of the mantissa is 0.5 or above, round to inf
|
|
|
|
if (flag)
|
|
{
|
|
// we need to add 1 LSB. However, since the mantissa always includes
|
|
// a hidden MSB of 1, i.e. 2^e * 1, we need to subtract that afterwards.
|
|
|
|
unsigned int c1 = t & 0xFF800000L ; // 2^e * 1
|
|
unsigned int c2 = c1 | 0x00010000L ; // LSB
|
|
|
|
x -= FLOATCAST(c1);
|
|
x += FLOATCAST(c2);
|
|
}
|
|
|
|
return x ;
|
|
}
|
|
|
|
float CPrediction::CPredictionState::GetPredictedValue (void)
|
|
{
|
|
// description: performs prediction for one MDCT bin
|
|
// returns: predicted value
|
|
// input: state variable handle, prediction buffer handle
|
|
|
|
float k [CPrediction::Order] ;
|
|
|
|
for (int i = 0 ; i < CPrediction::Order ; i++)
|
|
{
|
|
// compute (b / VAR) * COR
|
|
|
|
k [i] = m_var [i].GetBDivVar () * m_cor [i] ;
|
|
}
|
|
|
|
// compute the estimate, round it to nearest infinity and store it
|
|
|
|
return FloatRoundInfinity (k [0] * m_r [0] + k [1] * m_r [1]) ;
|
|
}
|
|
|
|
void CPrediction::CPredictionState::Update (float value)
|
|
{
|
|
const float ALPHA = 0.90625F ;
|
|
const float A = 0.953125F ;
|
|
|
|
float e [CPrediction::Order] ;
|
|
|
|
float k0 = m_cor [0] * m_var [0].GetBDivVar () ;
|
|
|
|
e [0] = value ;
|
|
e [1] = e [0] - k0 * m_r [0] ;
|
|
|
|
for (int i = 0 ; i < CPrediction::Order ; i++)
|
|
{
|
|
float r = m_r [i] ;
|
|
|
|
m_var [i] = ALPHA * m_var [i] + (0.5F) * (r * r + e [i] * e [i]) ;
|
|
m_cor [i] = ALPHA * m_cor [i] + e [i] * r ;
|
|
}
|
|
|
|
m_r [1] = A * (m_r [0] - k0 * e [0]) ;
|
|
m_r [0] = A * e [0] ;
|
|
}
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
// CPrediction
|
|
|
|
CPrediction::CPrediction ()
|
|
{
|
|
}
|
|
|
|
CPrediction::~CPrediction ()
|
|
{
|
|
}
|
|
|
|
void CPrediction::FullReset (void)
|
|
{
|
|
for (int i = 0 ; i < CPrediction::MaximumPredictedBins ; i++)
|
|
{
|
|
m_State [i].Reset () ;
|
|
}
|
|
}
|
|
|
|
void CPrediction::Apply (const CChannelInfo &info, CBlock &spectrum)
|
|
{
|
|
// short blocks
|
|
|
|
if (info.IsShortBlock ())
|
|
{
|
|
FullReset () ;
|
|
return ;
|
|
}
|
|
|
|
// long blocks
|
|
|
|
const int *BandOffsets = info.GetScaleFactorBandOffsets () ;
|
|
|
|
// apply predicted value to transmitted error value
|
|
|
|
if (info.GetPredictorDataPresent ())
|
|
{
|
|
for (int band = 0 ; band < info.GetMaximumPredictionBands () ; band++)
|
|
{
|
|
if (info.GetPredictionUsedForBand (band))
|
|
{
|
|
for (int index = BandOffsets [band] ; index < BandOffsets [band + 1] ; index++)
|
|
{
|
|
spectrum.AccessSpectralData () [index] += m_State [index].GetPredictedValue () ;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// update state
|
|
|
|
for (int band = 0 ; band < info.GetMaximumPredictionBands () ; band++)
|
|
{
|
|
for (int index = BandOffsets [band] ; index < BandOffsets [band + 1] ; index++)
|
|
{
|
|
m_State [index].Update (spectrum.AccessSpectralData () [index]) ;
|
|
}
|
|
}
|
|
|
|
// perform cyclic reset
|
|
|
|
if (info.GetPerformPredictorReset ())
|
|
{
|
|
int group = info.GetPredictorResetGroupNumber () - 1 ;
|
|
int maxbin = BandOffsets [info.GetMaximumPredictionBands ()] ;
|
|
|
|
for (int index = group ; index < maxbin ; index += 30)
|
|
{
|
|
m_State [index].Reset () ;
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif
|