/* ***** BEGIN LICENSE BLOCK ***** * Source last modified: $Id: updownmix.cpp,v 1.3.8.1 2004/07/09 02:08:08 hubbe Exp $ *  * Portions Copyright (c) 1995-2004 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 (the "RPSL") available at * http://www.helixcommunity.org/content/rpsl unless you have licensed * the file under the current version of the RealNetworks Community * Source License (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. *  * Alternatively, the contents of this file may be used under the * terms of the GNU General Public License Version 2 or later (the * "GPL") in which case the provisions of the GPL are applicable * instead of those above. If you wish to allow use of your version of * this file only under the terms of the GPL, and not to allow others * to use your version of this file under the terms of either the RPSL * or RCSL, indicate your decision by deleting the provisions above * and replace them with the notice and other provisions required by * the GPL. If you do not delete the provisions above, a recipient may * use your version of this file under the terms of any one of the * RPSL, the RCSL or the GPL. *  * 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 ***** */#include "hxassert.h"#include "mixengine.h"#include "math64.h"#ifdef HELIX_FEATURE_LIMITER#include "limiter.h"#endif#define MINUS3DB .707106781186547524 /* sqrt(2)/2 *//***************************************************************************** * * The upmix and downmix machinery. * ****************************************************************************/typedef struct UpMixMachine {  int offsetIn, offsetOut ;  const struct UpMixMachine *nextState ;} tUpMixMachine ;static const tUpMixMachine up_id[1] ={    {        1,1,        &up_id[0]    }} ;static const tUpMixMachine up_1_2[2] ={    {        0,1,        &up_1_2[1]    },    {        1,1,        &up_1_2[0]    }} ;/* mix mono into L,R instead of C */static const tUpMixMachine up_1_5[2] ={    {        0,1,        &up_1_5[1]    },    {        1,4,        &up_1_5[0]    }} ;/* mix mono into L,R instead of C */static const tUpMixMachine up_1_6[2] ={    {        0,1,        &up_1_6[1]    },    {        1,5,        &up_1_6[0]    }} ;static const tUpMixMachine up_2_5[2] ={    {        1,1,        &up_2_5[1]    },    {        1,4,        &up_2_5[0]    }} ;static const tUpMixMachine up_4_6[5] ={    {        1,1,        &up_4_6[1]    },    {        1,1,        &up_4_6[2]    },    {        1,2,        &up_4_6[3]    },    {        0,1,        &up_4_6[4]    },    {        1,1,        &up_4_6[0]    }} ;static const tUpMixMachine up_5_6[5] ={    {        1,1,        &up_5_6[1]    },    {        1,1,        &up_5_6[2]    },    {        1,2,        &up_5_6[3]    },    {        1,1,        &up_5_6[4]    },    {        1,1,        &up_5_6[0]    }} ;HX_RESULT HXAudioSvcMixEngine::SetupUpDownmix(void){    // we'll need something more intelligent for multichannel    m_nChannels_2_3 = MIN(m_nChannels_1, m_nChannels_4) ;    // initialize downmix    if (m_nChannels_1 != m_nChannels_2_3)    {      if (m_nChannels_1 == 2 && m_nChannels_2_3 == 1)          m_pfDownmix = &HXAudioSvcMixEngine::downmix2_1 ;      else if (m_nChannels_1 == 5 && m_nChannels_2_3 == 1)          m_pfDownmix = &HXAudioSvcMixEngine::downmix5_1 ;      else if (m_nChannels_1 == 6 && m_nChannels_2_3 == 2)          m_pfDownmix = &HXAudioSvcMixEngine::downmix6_2_matrix ;      else if (m_nChannels_1 == 5 && m_nChannels_2_3 == 2)          m_pfDownmix = &HXAudioSvcMixEngine::downmix5_2_matrix ;      else if (m_nChannels_1 == 4 && m_nChannels_2_3 == 2)          m_pfDownmix = &HXAudioSvcMixEngine::downmix4_2_matrix ;      else          return HXR_FAIL ;      /* If we downmix, we limit. Special-case stereo to mono: create one bit of         headroom, don't limit */#if HELIX_FEATURE_LIMITER      if (!(m_nChannels_1 == 2 && m_nChannels_2_3 == 1))          m_pLimiter = LimiterInit(m_ulSampleRate_3_4, m_nChannels_2_3, HEADROOM) ;      else#endif          m_pLimiter = 0 ;    }    // initialize upmix    if (m_nChannels_2_3 == m_nChannels_4)        m_upmixMachine = up_id ;    else if (m_nChannels_2_3 == 1 && m_nChannels_4 == 2)        m_upmixMachine = up_1_2 ;    else if (m_nChannels_2_3 == 1 && m_nChannels_4 == 5)        m_upmixMachine = up_1_5 ;    else if (m_nChannels_2_3 == 1 && m_nChannels_4 == 6)        m_upmixMachine = up_1_6 ;    else if (m_nChannels_2_3 == 2 && m_nChannels_4 == 5)        m_upmixMachine = up_2_5 ;    else if (m_nChannels_2_3 == 5 && m_nChannels_4 == 6)        m_upmixMachine = up_5_6 ;    else if (m_nChannels_2_3 == 4 && m_nChannels_4 == 6)        m_upmixMachine = up_4_6 ;    else        return HXR_FAIL ;    m_clev = m_slev = (int)((1UL<<31) * MINUS3DB) ; // -3 dB is default attenuation    return HXR_OK ;}/* saturated 16-bit add */INT16 adds16(INT16 a, INT16 b){    INT32 s = (INT32)a+b ;    if (s > 0x7fff) s = 0x7fff ;    else if (s < -0x8000) s = -0x8000 ;    return (INT16)s ;}/* saturated 32-bit add */INT32 adds32(INT32 a, INT32 b){    INT32 s = a+b ;    INT32 ov = ~(a ^ b) & (a ^ s) & 0x80000000 ; // overflow    if (ov)        s = (signed)((1UL<<31)-1)-((s ^ ov) >> 31) ;    return s ;}/* mix into a 32-bit buffer. Returns the number of samples written (more precisely,   if we mix 2 channels into a 5 channel buffer, and feed 2*n samples, then this   function will return 5*n samples, regardless into how many channels the 2 original   channels are mixed. */UINT32 HXAudioSvcMixEngine::upmix(const tAudioSample *pIn, INT32 *pOut0, const tUpMixMachine *pUpmixMachine, int nSamples, BOOL isDirty){    INT32 *pOut = pOut0 ;    HX_ASSERT(nSamples % m_nChannels_2_3 == 0) ;    const tAudioSample *pEnd = pIn + nSamples ;    if (!isDirty)    {        while (pIn != pEnd)        {            *pOut = adds32(*pIn << (32-NBITS_PER_AUDIOSAMPLE), *pOut);            pIn  += pUpmixMachine->offsetIn  ;            pOut += pUpmixMachine->offsetOut ;            pUpmixMachine = pUpmixMachine->nextState ;        }    }    else    {        while (pIn != pEnd)        {            INT32 t = (INT32)*pIn << (32-NBITS_PER_AUDIOSAMPLE) ; // -MulShift31(*pIn,pUpmixMachine->gain)            *pOut = t ;            pIn  += pUpmixMachine->offsetIn  ;            pOut += pUpmixMachine->offsetOut ;            pUpmixMachine = pUpmixMachine->nextState ;        }    }    return pOut - pOut0 ;}/* mix into a 16-bit buffer. Returns the number of samples written (more precisely,   if we mix 2 channels into a 5 channel buffer, and feed 2*n samples, then this   function will return 5*n samples, regardless into how many channels the 2 original   channels are mixed. */UINT32 HXAudioSvcMixEngine::upmix(const tAudioSample *pIn, INT16 *pOut0, const tUpMixMachine *pUpmixMachine, int nSamples, BOOL isDirty){    INT16 *pOut = pOut0 ;    HX_ASSERT(nSamples % m_nChannels_2_3 == 0) ;    const tAudioSample *pEnd = pIn + nSamples ;    if (!isDirty)    {        while (pIn != pEnd)        {            *pOut = adds16((INT16)(*pIn >> (NBITS_PER_AUDIOSAMPLE-16)), *pOut);            pIn  += pUpmixMachine->offsetIn  ;            pOut += pUpmixMachine->offsetOut ;            pUpmixMachine = pUpmixMachine->nextState ;        }    }    else    {        while (pIn != pEnd)        {            *pOut = (INT16)(*pIn >> (NBITS_PER_AUDIOSAMPLE-16)) ;            pIn  += pUpmixMachine->offsetIn  ;            pOut += pUpmixMachine->offsetOut ;            pUpmixMachine = pUpmixMachine->nextState ;        }    }    return pOut - pOut0 ;}void HXAudioSvcMixEngine::downmix2_1(tAudioSample *pBuffer, int nSamples){    enum { L,R,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    while (pBuffer != pEnd)    {        *pOut++ = (pBuffer[L]>>1) + (pBuffer[R]>>1) ;        pBuffer += strideIn ;    }}void HXAudioSvcMixEngine::downmix5_1(tAudioSample *pBuffer, int nSamples){    enum { L,R,C,Ls,Rs,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    const int clev = m_clev >> (HEADROOM-1);    const int slev = m_slev >> (HEADROOM-2);    while (pBuffer != pEnd)    {        INT32 c  = MulShift32(pBuffer[C], clev) ;        INT32 cs = MulShift32((pBuffer[Ls]>>1) + (pBuffer[Rs]>>1), slev) ;        *pOut++  = (pBuffer[L]>>HEADROOM) + c + (pBuffer[R]>>HEADROOM) + cs ;        pBuffer += strideIn ;    }}// Matrix surround downmixvoid HXAudioSvcMixEngine::downmix5_2_matrix(tAudioSample *pBuffer, int nSamples){    enum { L,R,C,Ls,Rs,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    const int clev = m_clev >> (HEADROOM-1);    const int slev = m_slev >> (HEADROOM-2);    while (pBuffer != pEnd)    {        INT32 c  = MulShift32(pBuffer[C], clev) ; // creates two bits headroom        INT32 cs = MulShift32((pBuffer[Ls]>>1) + (pBuffer[Rs]>>1), slev) ; // two bits hr        pOut[0]  = (pBuffer[L]>>HEADROOM) + c + cs ;        pOut[1]  = (pBuffer[R]>>HEADROOM) + c - cs ;        pBuffer += strideIn ;        pOut    += 2 ;    }}// Stereo downmixvoid HXAudioSvcMixEngine::downmix5_2_stereo(tAudioSample *pBuffer, int nSamples){    enum { L,R,C,Ls,Rs,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    const int clev = m_clev >> (HEADROOM-1);    const int slev = m_slev >> (HEADROOM-1);    while (pBuffer != pEnd)    {        INT32 c = MulShift32(pBuffer[C], clev) ;        pOut[0] = (pBuffer[L]>>HEADROOM) + c + MulShift32(pBuffer[Ls], slev) ;        pOut[1] = (pBuffer[R]>>HEADROOM) + c + MulShift32(pBuffer[Rs], slev) ;        pBuffer += strideIn ;        pOut    += 2 ;    }}// Matrix surround downmixvoid HXAudioSvcMixEngine::downmix6_2_matrix(tAudioSample *pBuffer, int nSamples){    enum { L,R,C,LFE,Ls,Rs,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    const int clev = m_clev >> (HEADROOM-1);    const int slev = m_slev >> (HEADROOM-2);    while (pBuffer != pEnd)    {        INT32 c  = MulShift32(pBuffer[C], clev) ; // creates two bits headroom        INT32 cs = MulShift32((pBuffer[Ls]>>1) + (pBuffer[Rs]>>1), slev) ; // two bits hr        pOut[0]  = (pBuffer[L]>>HEADROOM) + c + cs ;        pOut[1]  = (pBuffer[R]>>HEADROOM) + c - cs ;        pBuffer += strideIn ;        pOut    += 2 ;    }}// Stereo downmixvoid HXAudioSvcMixEngine::downmix6_2_stereo(tAudioSample *pBuffer, int nSamples){    enum { L,R,C,LFE,Ls,Rs,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    const int clev = m_clev >> (HEADROOM-1);    const int slev = m_slev >> (HEADROOM-1);    while (pBuffer != pEnd)    {        INT32 c = MulShift32(pBuffer[C], clev) ;        pOut[0] = (pBuffer[L]>>HEADROOM) + c + MulShift32(pBuffer[Ls], slev) ;        pOut[1] = (pBuffer[R]>>HEADROOM) + c + MulShift32(pBuffer[Rs], slev) ;        pBuffer += strideIn ;        pOut    += 2 ;    }}// Matrix surround downmixvoid HXAudioSvcMixEngine::downmix4_2_matrix(tAudioSample *pBuffer, int nSamples){    enum { L,R,C,Cs,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    const int clev = m_clev >> (HEADROOM-1);    const int slev = m_slev >> (HEADROOM-1);    while (pBuffer != pEnd)    {        INT32 c  = MulShift32(pBuffer[C], clev) ; // creates two bits headroom        INT32 cs = MulShift32(pBuffer[Cs], slev) ; // two bits hr        pOut[0]  = (pBuffer[L]>>HEADROOM) + c + cs ;        pOut[1]  = (pBuffer[R]>>HEADROOM) + c - cs ;        pBuffer += strideIn ;        pOut    += 2 ;    }}// Stereo downmixvoid HXAudioSvcMixEngine::downmix4_2_stereo(tAudioSample *pBuffer, int nSamples){    enum { L,R,C,Cs,strideIn } ; // input channel ordering    HX_ASSERT(nSamples % strideIn == 0) ;    const tAudioSample *pEnd = pBuffer + nSamples ;    tAudioSample *pOut = pBuffer;    const int clev = m_clev >> (HEADROOM-1);    const int slev = m_slev >> (HEADROOM-1);    while (pBuffer != pEnd)    {        INT32 c = MulShift32(pBuffer[C], clev) ;        INT32 cs = MulShift32(pBuffer[Cs], slev) ; // two bits hr        pOut[0] = (pBuffer[L]>>HEADROOM) + c + cs ;        pOut[1] = (pBuffer[R]>>HEADROOM) + c + cs ;        pBuffer += strideIn ;        pOut    += 2 ;    }}