sconceal.h
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上传日期:2007-06-06
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- /* ***** BEGIN LICENSE BLOCK *****
- * Version: RCSL 1.0/RPSL 1.0
- *
- * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file, are
- * subject to the current version of the RealNetworks Public Source License
- * Version 1.0 (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the RealNetworks Community Source License Version 1.0
- * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
- * in which case the RCSL will apply. You may also obtain the license terms
- * directly from RealNetworks. You may not use this file except in
- * compliance with the RPSL or, if you have a valid RCSL with RealNetworks
- * applicable to this file, the RCSL. Please see the applicable RPSL or
- * RCSL for the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the portions
- * it created.
- *
- * This file, and the files included with this file, is distributed and made
- * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
- * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- #ifndef __CONCEALMENT_H__
- #define __CONCEALMENT_H__
- #include "hlxclib/assert.h"
- /*
- * class CConcealment keeps a history of spectral lines and tries
- * to conceal missing spectra.
- * Instantiate one per channel.
- */
- class CConcealment
- {
- public:
- // instantiate a spectrum concealer. nLinesMax is the maximum number
- // of lines that we'll ever take or hand out.
- CConcealment(int nLinesMax) ;
- ~CConcealment() ;
- // insert spectrum into our delay line. Currently, blocktype is of
- // Layer-3 flavor (2 == short block); this will be generalized.
- // nLines is the highest active spectral line in this block
- // (i.e. the audio bandwidth)
- void insert(const float *spec, int blocktype, int nLines = -1) ;
- // no spectrum present, schedule this spectrum to be concealed.
- // call this if you have a defect, or missing, spectrum.
- void insert() ;
- // retrieve a valid spectrum, concealed if necessary
- // returns index+1 of highest spectral line containing energy
- // and Layer-3 type blocktype.
- int retrieve(float *s, int &blocktype) ;
- private:
- enum
- {
- CONCEAL_REPETITION = 0,
- CONCEAL_INTERPOLATION = 1,
- CONCEAL_PREDICTION = 2
- };
- //
- // the most likely candidates for concealment. See source code
- // for documentation
- //
- void conceal(int method) ;
- void concealByPrediction() ;
- void adaptEnergy() ;
- void prediction() ;
- void predict(int nLines,
- const float *spec0,
- const float *spec1,
- const float *a0,
- const float *a1,
- const float *ma,
- float *current);
- void calculateCoefficients(/* input */
- int nLines,
- const float *g0,
- const float *g0p,
- const float *g1,
- const float *g1p,
- const float *g2,
- /* output */
- float *a0,
- float *a1);
- void poleLimitMagnitude(float mag, float *a0, float *a1) ;
- void rotateHistory() ;
- void zeroFloat(float *f, int n) ;
- //
- // inline helper functions to make access to history buffer
- // transparent
- //
- unsigned char& spectrumPresent(int time)
- {
- return m_historyPtr[time + sizeofHistory]->spectrumPresent;
- }
- int& blockType(int time)
- {
- return m_historyPtr[time + sizeofHistory]->blockType;
- }
- int& nLinesActive(int time)
- {
- return m_historyPtr[time + sizeofHistory]->nLinesActive;
- }
- float* spectrum(int time)
- {
- assert(sizeofHistory+time >= 0);
- assert(sizeofHistory+time < sizeofBuffer);
- return m_historyPtr[time + sizeofHistory]->spectrum;
- }
- //
- // member variables ...
- //
- enum
- {
- sizeofBuffer = 8,
- sizeofFuture = 2,
- sizeofHistory= sizeofBuffer-sizeofFuture-1,
- CONCEALLIMIT = 576 // can handle at most 576 lines.
- };
- int m_offset ;
- int m_nLinesMax ;
- struct
- {
- float * spectrum ;
- int nLinesActive ;
- unsigned char spectrumPresent ;
- int blockType ;
- } m_history[sizeofBuffer], *m_historyPtr[sizeofBuffer] ;
- unsigned char lastConcealed ;
- // last frame's predictor coefficients
- float a0[CONCEALLIMIT] ;
- float a1[CONCEALLIMIT] ;
- float ma[CONCEALLIMIT] ;
- float g0[CONCEALLIMIT], g0p[CONCEALLIMIT];
- float g1[CONCEALLIMIT], g1p[CONCEALLIMIT];
- float g2[CONCEALLIMIT];
- };
- #endif /* ifdef __CONCEALMENT_H__ */