#include "cmPrefix.h"
#include "cmGlobal.h"
#include "cmFloatTypes.h"
#include "cmComplexTypes.h"
#include "cmRpt.h"
#include "cmErr.h"
#include "cmCtx.h"
#include "cmMem.h"
#include "cmMallocDebug.h"
#include "cmLinkedHeap.h"
#include "cmText.h"
#include "cmMath.h"
#include "cmFile.h"
#include "cmFileSys.h"
#include "cmSymTbl.h"
#include "cmJson.h"
#include "cmPrefs.h"
#include "cmDspValue.h"
#include "cmMsgProtocol.h"
#include "cmThread.h" 
#include "cmUdpPort.h"
#include "cmUdpNet.h"
#include "cmSerialPort.h"
#include "cmTime.h"
#include "cmAudioSys.h"
#include "cmProcObj.h"
#include "cmDspCtx.h"
#include "cmDspClass.h"
#include "cmDspUi.h"
#include "cmAudioFile.h"

#include "cmProcObj.h"
#include "cmProcTemplateMain.h"
#include "cmProc.h"
#include "cmMidi.h"
#include "cmProc2.h"
#include "cmProc3.h"
#include "cmVectOpsTemplateMain.h"

#include "app/cmPickup.h"

#include "cmDspSys.h"

enum
{
  kBypassDyId,
  kTimeDyId,
  kFbDyId,
  kInDyId,
  kOutDyId
  
};

cmDspClass_t _cmDelayDC;

typedef struct
{
  cmDspInst_t  inst;
  cmMDelay*    delay;
} cmDspDelay_t;

cmDspInst_t*  _cmDspDelayAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  unsigned chs = 1;
  
  cmDspVarArg_t args[] =
  {
    { "bypass",kBypassDyId,0,0,   kInDsvFl  | kBoolDsvFl   | kOptArgDsvFl,  "Bypass enable flag." },
    { "time",  kTimeDyId, 0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl,  "Max delay time in milliseconds" },
    { "fb",    kFbDyId,   0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl,  "Feedback"  },
    { "in",    kInDyId,   0, 0,   kInDsvFl  | kAudioBufDsvFl,               "Audio input" },
    { "out",   kOutDyId,  0, chs, kOutDsvFl | kAudioBufDsvFl,               "Audio output." },
    { NULL, 0, 0, 0, 0 }
  };
  
  cmDspDelay_t* p  = cmDspInstAlloc(cmDspDelay_t,ctx,classPtr,args,instSymId,id,storeSymId,va_cnt,vl);
  
  // set default values for the parameters that were not explicitely set in the va_arg list
  cmDspSetDefaultBool(   ctx, &p->inst, kBypassDyId,0,   0 );
  cmDspSetDefaultUInt(   ctx, &p->inst, kTimeDyId,  0,   1000 );
  cmDspSetDefaultDouble( ctx, &p->inst ,kFbDyId,    0.0, 0.0 );
  
  cmReal_t dtimeMs =  cmDspDefaultUInt(&p->inst,kTimeDyId);
  cmReal_t fbCoeff = cmDspDefaultDouble(&p->inst,kFbDyId);
  
  p->delay = cmMDelayAlloc(ctx->cmProcCtx,NULL, cmDspSamplesPerCycle(ctx), cmDspSampleRate(ctx), fbCoeff,  1, &dtimeMs, NULL  );
  
  return &p->inst;
}

cmDspRC_t _cmDspDelayFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  cmDspDelay_t* p  = (cmDspDelay_t*)inst;
  
  cmMDelayFree(&p->delay);
  
  //cmCtxFree(&ampp-&gtctx);
  
  return rc;
}

cmDspRC_t _cmDspDelayReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  
  rc = cmDspApplyAllDefaults(ctx,inst);
  
  return rc;  
}

cmDspRC_t _cmDspDelayExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspDelay_t* p  = (cmDspDelay_t*)inst;
  cmDspRC_t     rc = kOkDspRC;
  
  unsigned          iChIdx  = 0;
  const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,kInDyId,iChIdx);
  unsigned          iSmpCnt = cmDspVarRows(inst,kInDyId);
  
  unsigned          oChIdx  = 0;
  cmSample_t*       op      = cmDspAudioBuf(ctx,inst,kOutDyId,oChIdx);
  unsigned          oSmpCnt = cmDspVarRows(inst,kOutDyId);
  
  bool              bypassFl= cmDspBool(inst,kBypassDyId);
  
  cmMDelayExec(p->delay,ip,op,cmMin(iSmpCnt,oSmpCnt),bypassFl);
  
  return rc;
}

cmDspRC_t _cmDspDelayRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspDelay_t* p = (cmDspDelay_t*)inst;
  cmDspRC_t     rc= kOkDspRC;
  
  cmDspSetEvent(ctx,inst,evt);
  
  switch( evt->dstVarId )
  {
  case kBypassDyId:
    break;
    
  case kTimeDyId:
    p->delay->delayArray[0].delayMs = cmDspDouble(inst,kTimeDyId);
    break;
    
  case kFbDyId:
    p->delay->fbCoeff  = cmDspDouble(inst,kFbDyId);
    break;
    
  default:
    { assert(0); }
  }
  return rc;
}

cmDspClass_t* cmDelayClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmDelayDC,ctx,"Delay",
  NULL,
  _cmDspDelayAlloc,
  _cmDspDelayFree,
  _cmDspDelayReset,
  _cmDspDelayExec,
  _cmDspDelayRecv,
  NULL,NULL,
  "Simple delay.");
  
  return &_cmDelayDC;
}

enum
{
  kBypassMtId,
  kScaleMtId,
  kFbMtId,
  kInMtId,
  kOutMtId,
  kBaseMsMtId
  
};

cmDspClass_t _cmMtDelayDC;

typedef struct
{
  cmDspInst_t  inst;
  cmMDelay*    p;
  unsigned     baseGainMtId;
  unsigned     tapCnt;
  cmReal_t*    msV;
  cmReal_t*    gainV;
  unsigned     printSymId;
} cmDspMtDelay_t;

// args: bypassFl, time_scale, feedback, tap_ms0, tap_gain0, tapms1, tap_gain1, ....

cmDspInst_t*  _cmDspMtDelayAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  va_list vl1;
  
  cmDspVarArg_t args[] =
  {
    { "bypass",kBypassMtId,0, 0,   kInDsvFl  | kBoolDsvFl   | kReqArgDsvFl,  "Bypass enable flag." },
    { "scale", kScaleMtId, 0, 0,   kInDsvFl  | kDoubleDsvFl | kReqArgDsvFl,  "Scale tap times. (0.0 - 1.0)" },
    { "fb",    kFbMtId,    0, 0,   kInDsvFl  | kDoubleDsvFl | kReqArgDsvFl,  "Feedback"  },
    { "in",    kInMtId,    0, 0,   kInDsvFl  | kAudioBufDsvFl,               "Audio input" },
    { "out",   kOutMtId,   0, 1,   kOutDsvFl | kAudioBufDsvFl,               "Audio output." },
  };
  
  // verify that at least one var arg exists
  if( va_cnt < 5 || cmIsEvenU(va_cnt) )
  {
    cmDspClassErr(ctx,classPtr,kInvalidArgDspRC,"The 'multi-tap delay requires at least 5 arguments. Three fixed arguments and groups of two tap specification arguments.");
    return NULL;
  }    
  
  va_copy(vl1,vl);
  
  unsigned      reqArgCnt    = 3;
  unsigned      fixArgCnt    = sizeof(args)/sizeof(args[0]);
  unsigned      tapCnt       = (va_cnt - reqArgCnt)/2;
  cmReal_t*     msV          = cmMemAllocZ(cmReal_t,tapCnt);
  cmReal_t*     gainV        = cmMemAllocZ(cmReal_t,tapCnt);
  
  unsigned      argCnt       = fixArgCnt + 2 * tapCnt;
  unsigned      baseGainMtId = kBaseMsMtId + tapCnt;
  cmDspVarArg_t a[ argCnt+1 ];
  unsigned      i;
  
  // Get the taps and gains
  va_arg(vl1,int);     // enable
  va_arg(vl1,double);   // time scale
  va_arg(vl1,double);   // feedback
  for(i=0; i<tapCnt; ++i)
  {
    msV[i]   = va_arg(vl1,double);
    gainV[i] = va_arg(vl1,double);
  }
  
  
  // setup the output gain args 
  cmDspArgCopy(       a, argCnt, 0, args, fixArgCnt );
  cmDspArgSetupN(ctx, a, argCnt, kBaseMsMtId,  tapCnt, "ms",   kBaseMsMtId,  0, 0, kInDsvFl | kDoubleDsvFl, "Tap delay times in milliseconds.");
  cmDspArgSetupN(ctx, a, argCnt, baseGainMtId, tapCnt, "gain", baseGainMtId, 0, 0, kInDsvFl | kDoubleDsvFl, "Tap delay linear gain.");
  cmDspArgSetupNull(  a+argCnt);  // set terminating arg. flag
  
  cmDspMtDelay_t* p  = cmDspInstAlloc(cmDspMtDelay_t,ctx,classPtr,a,instSymId,id,storeSymId,reqArgCnt,vl1);
  
  
  p->p            = cmMDelayAlloc(ctx->cmProcCtx,NULL,0, 0, 0, 0, NULL, NULL  );
  p->baseGainMtId = baseGainMtId;
  p->tapCnt       = tapCnt;
  p->msV          = msV;
  p->gainV        = gainV;
  p->printSymId   = cmSymTblRegisterStaticSymbol(ctx->stH,"_print");
  
  for(i=0; i<tapCnt; ++i)
  {
    cmDspSetDefaultDouble(ctx,&p->inst,kBaseMsMtId+i,   0.0, msV[i]);
    cmDspSetDefaultDouble(ctx,&p->inst,baseGainMtId+i,  0.0, gainV[i]);
  }
  
  va_end(vl1);
  return &p->inst;
}

cmDspRC_t _cmDspMtDelayFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  cmDspMtDelay_t* p  = (cmDspMtDelay_t*)inst;
  
  cmMemFree(p->msV);
  cmMemFree(p->gainV);
  
  cmMDelayFree(&p->p);
  
  return rc;
}

cmDspRC_t _cmDspMtDelayReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  cmDspMtDelay_t* p  = (cmDspMtDelay_t*)inst;
  
  if((rc = cmDspApplyAllDefaults(ctx,inst)) == kOkDspRC )
  {
    cmMDelayInit(p->p,cmDspSamplesPerCycle(ctx), cmDspSampleRate(ctx), cmDspDouble(&p->inst,kFbMtId), p->tapCnt, p->msV, p->gainV  );    
  }
  
  return rc;  
}

cmDspRC_t _cmDspMtDelayExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspMtDelay_t* p  = (cmDspMtDelay_t*)inst;
  cmDspRC_t     rc = kOkDspRC;
  
  unsigned          iChIdx  = 0;
  const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,kInMtId,iChIdx);
  unsigned          iSmpCnt = cmDspVarRows(inst,kInMtId);
  
  unsigned          oChIdx  = 0;
  cmSample_t*       op      = cmDspAudioBuf(ctx,inst,kOutMtId,oChIdx);
  unsigned          oSmpCnt = cmDspVarRows(inst,kOutMtId);
  
  bool              bypassFl= cmDspBool(inst,kBypassMtId);
  
  if( ip != NULL )
    cmMDelayExec(p->p,ip,op,cmMin(iSmpCnt,oSmpCnt),bypassFl);
  
  return rc;
}

cmDspRC_t _cmDspMtDelayRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspMtDelay_t* p = (cmDspMtDelay_t*)inst;
  cmDspRC_t     rc= kOkDspRC;
  
  cmDspSetEvent(ctx,inst,evt);
  
  // set tap times
  if( kBaseMsMtId <= evt->dstVarId && evt->dstVarId < kBaseMsMtId + p->p->delayCnt )
    cmMDelaySetTapMs(p->p,evt->dstVarId - kBaseMsMtId, cmDspDouble(inst,evt->dstVarId));
  else
    // set tap gains
  if( p->baseGainMtId <= evt->dstVarId && evt->dstVarId < p->baseGainMtId + p->p->delayCnt )
    cmMDelaySetTapGain(p->p,evt->dstVarId - p->baseGainMtId, cmDspDouble(inst,evt->dstVarId));
  else
  {
    switch( evt->dstVarId )
    {
    case kScaleMtId:
      //cmDspDouble(inst,kScaleMtId);
      break;
      
    case kFbMtId:
      p->p->fbCoeff  = cmDspDouble(inst,kFbMtId);
      break;
      
    }
  }
  return rc;
}

cmDspRC_t  _cmDspMtDelayRecvFunc(   cmDspCtx_t* ctx, cmDspInst_t*  inst,  unsigned attrSymId, const cmDspValue_t* value )
{
  cmDspRC_t       rc = kOkDspRC;
  cmDspMtDelay_t* p  = (cmDspMtDelay_t*)inst;
  
  if( cmDsvIsSymbol(value) && (cmDsvSymbol(value)==p->printSymId) )
  {
    int i;
    cmRptPrintf(ctx->rpt,"taps:%i\n",p->tapCnt);
    for(i=0; i<p->tapCnt; ++i)
      cmRptPrintf(ctx->rpt,"%f %f\n",p->msV[i],p->gainV[i]);
    
    cmMDelayReport(p->p, ctx->rpt );
  }
  
  return rc;
}


cmDspClass_t* cmMtDelayClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmMtDelayDC,ctx,"MtDelay",
  NULL,
  _cmDspMtDelayAlloc,
  _cmDspMtDelayFree,
  _cmDspMtDelayReset,
  _cmDspMtDelayExec,
  _cmDspMtDelayRecv,
  NULL,
  _cmDspMtDelayRecvFunc,
  "Multi-tap delay.");
  
  return &_cmMtDelayDC;
}

enum
{
  kBypassPsId,
  kRatioPsId,
  kInPsId,
  kOutPsId
};

cmDspClass_t _cmPShiftDC;

typedef struct
{
  cmDspInst_t   inst;
  //cmCtx*        ctx;
  cmPitchShift* pshift;
} cmDspPShift_t;

cmDspInst_t*  _cmDspPShiftAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  unsigned chs = 1;
  
  cmDspVarArg_t args[] =
  {
    { "bypass",kBypassPsId, 0, 0,   kInDsvFl  | kBoolDsvFl   | kOptArgDsvFl,  "Bypass enable flag." },
    { "ratio", kRatioPsId,  0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl,  "Ratio"  },
    { "in",    kInPsId,     0, 0,   kInDsvFl  | kAudioBufDsvFl,               "Audio input" },
    { "out",   kOutPsId,    0, chs, kOutDsvFl | kAudioBufDsvFl,               "Audio output." },
    { NULL, 0, 0, 0, 0 }
  };
  
  cmDspPShift_t* p  = cmDspInstAlloc(cmDspPShift_t,ctx,classPtr,args,instSymId,id,storeSymId,va_cnt,vl);
  
  // set default values for the parameters that were not explicitely set in the va_arg list
  cmDspSetDefaultBool(   ctx, &p->inst, kBypassPsId,  0,     0 );
  cmDspSetDefaultDouble( ctx, &p->inst ,kRatioPsId,   0.0, 1.0 );
  
  p->pshift = cmPitchShiftAlloc(ctx->cmProcCtx,NULL,cmDspSamplesPerCycle(ctx), cmDspSampleRate(ctx)  );
  
  return &p->inst;
}

cmDspRC_t _cmDspPShiftFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t      rc = kOkDspRC;
  cmDspPShift_t* p  = (cmDspPShift_t*)inst;
  
  cmPitchShiftFree(&p->pshift);
  
  //cmCtxFree(&ampp-&gtctx);
  
  return rc;
}

cmDspRC_t _cmDspPShiftReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  
  rc = cmDspApplyAllDefaults(ctx,inst);
  
  return rc;  
}

cmDspRC_t _cmDspPShiftExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspPShift_t* p  = (cmDspPShift_t*)inst;
  cmDspRC_t      rc = kOkDspRC;
  
  unsigned          iChIdx  = 0;
  const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,kInPsId,iChIdx);
  unsigned          iSmpCnt = cmDspVarRows(inst,kInPsId);
  
  unsigned          oChIdx  = 0;
  cmSample_t*       op      = cmDspAudioBuf(ctx,inst,kOutPsId,oChIdx);
  unsigned          oSmpCnt = cmDspVarRows(inst,kOutPsId);
  
  bool              bypassFl= cmDspBool(inst,kBypassPsId);
  
  cmPitchShiftExec(p->pshift,ip,op,cmMin(iSmpCnt,oSmpCnt),cmDspDouble(inst,kRatioPsId),bypassFl);
  
  return rc;
}

cmDspRC_t _cmDspPShiftRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  return cmDspSetEvent(ctx,inst,evt);
}

cmDspClass_t* cmPShiftClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmPShiftDC,ctx,"PShift",
  NULL,
  _cmDspPShiftAlloc,
  _cmDspPShiftFree,
  _cmDspPShiftReset,
  _cmDspPShiftExec,
  _cmDspPShiftRecv,
  NULL,NULL,
  "Pitch Shifter.");
  
  return &_cmPShiftDC;
}

enum
{
  kTimeLrId,
  kPGainLrId,
  kRGainLrId,
  kBypassLrId,
  kPlayLrId,
  kRecdLrId,
  kRatioLrId,
  kInLrId,
  kOutLrId
  
};

cmDspClass_t _cmLoopRecdDC;

typedef struct
{
  cmDspInst_t     inst;
  //cmCtx*          ctx;
  bool            playFl;
  cmLoopRecord*   lrp;
} cmDspLoopRecd_t;

cmDspInst_t*  _cmDspLoopRecdAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  unsigned chs = 1;
  
  cmDspVarArg_t args[] =
  {
    { "time",  kTimeLrId,  0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl,  "Max record time in seconds" },
    { "pgain", kPGainLrId, 0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl,  "Pass-through gain."},
    { "rgain", kRGainLrId, 0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl,  "Recorder out gain."},
    { "bypass",kBypassLrId,0, 0,   kInDsvFl  | kBoolDsvFl,                   "Bypass flag"},
    { "play",  kPlayLrId,  0, 0,   kInDsvFl  | kBoolDsvFl,                   "Play gate flag"  },
    { "recd",  kRecdLrId,  0, 0,   kInDsvFl  | kBoolDsvFl,                   "Recd gate flag" },
    { "ratio", kRatioLrId, 0, 0,   kInDsvFl  | kDoubleDsvFl,                 "Playback speed ratio"},
    { "in",    kInLrId,    0, 0,   kInDsvFl  | kAudioBufDsvFl,               "Audio input" },
    { "out",   kOutLrId,   0, chs, kOutDsvFl | kAudioBufDsvFl,               "Audio output." },
    { NULL, 0, 0, 0, 0 }
  };
  
  cmDspLoopRecd_t* p  = cmDspInstAlloc(cmDspLoopRecd_t,ctx,classPtr,args,instSymId,id,storeSymId,va_cnt,vl);
  
  // set default values for the parameters that were not explicitely set in the va_arg list
  cmDspSetDefaultDouble(   ctx, &p->inst, kTimeLrId,   0,   10 );
  cmDspSetDefaultDouble(   ctx, &p->inst, kPGainLrId,   0,  1.0 );
  cmDspSetDefaultDouble(   ctx, &p->inst, kRGainLrId,   0,  1.0 );
  cmDspSetDefaultBool(     ctx, &p->inst, kBypassLrId, 0,    0 ); 
  cmDspSetDefaultBool(     ctx, &p->inst, kPlayLrId,   0,    0 );
  cmDspSetDefaultBool(     ctx, &p->inst, kRecdLrId,   0,    0 );
  cmDspSetDefaultDouble(   ctx, &p->inst, kRatioLrId,  0,   1.0);
  
  p->lrp   = cmLoopRecordAlloc(ctx->cmProcCtx,NULL,0,0,0   );
  
  return &p->inst;
}

cmDspRC_t _cmDspLoopRecdFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  cmDspLoopRecd_t* p  = (cmDspLoopRecd_t*)inst;
  
  cmLoopRecordFree(&p->lrp);
  
  //cmCtxFree(&ampp-&gtctx);
  
  return rc;
}

cmDspRC_t _cmDspLoopRecdReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  cmDspLoopRecd_t* p  = (cmDspLoopRecd_t*)inst;
  
  rc = cmDspApplyAllDefaults(ctx,inst);
  
  cmReal_t   maxRecdTimeSecs  =  cmDspDefaultDouble(&p->inst,kTimeLrId);
  unsigned   maxRecdTimeSmps  = floor(cmDspSampleRate(ctx) * maxRecdTimeSecs);
  unsigned   xfadeTimeSmps    = floor(cmDspSampleRate(ctx) * 50.0/1000.0);
  
  if( maxRecdTimeSmps != p->lrp->maxRecdSmpCnt || xfadeTimeSmps != p->lrp->xfadeSmpCnt )
    cmLoopRecordInit(p->lrp,cmDspSamplesPerCycle(ctx),maxRecdTimeSmps,xfadeTimeSmps);
  
  return rc;  
}

cmDspRC_t _cmDspLoopRecdExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspLoopRecd_t* p  = (cmDspLoopRecd_t*)inst;
  cmDspRC_t        rc = kOkDspRC;
  
  unsigned          iChIdx  = 0;
  const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,kInLrId,iChIdx);
  unsigned          iSmpCnt = cmDspVarRows(inst,kInLrId);
  
  unsigned          oChIdx  = 0;
  cmSample_t*       op      = cmDspAudioBuf(ctx,inst,kOutLrId,oChIdx);
  unsigned          oSmpCnt = cmDspVarRows(inst,kOutLrId);
  
  bool               recdFl   = cmDspBool(inst,kRecdLrId);
  bool               bypassFl = cmDspBool(inst,kBypassLrId);
  double             ratio    = cmDspDouble(inst,kRatioLrId);
  
  double           rgain    = cmDspDouble(inst,kRGainLrId);  // recorder output gain
  double           pgain    = cmDspDouble(inst,kPGainLrId);  // pass through gain
  
  if( ip != NULL && op != NULL )
    cmLoopRecordExec(p->lrp,ip,op,cmMin(iSmpCnt,oSmpCnt), bypassFl, recdFl, p->playFl, ratio, pgain, rgain );
  
  
  p->playFl = false;
  
  return rc;
}

cmDspRC_t _cmDspLoopRecdRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspLoopRecd_t* p = (cmDspLoopRecd_t*)inst;
  cmDspRC_t       rc = cmDspSetEvent(ctx,inst,evt);
  
  
  switch(evt->dstVarId)
  {
  case kPlayLrId:
    p->playFl = cmDspBool(inst,kPlayLrId);
    break;
  }
  
  return rc;
}

cmDspClass_t* cmLoopRecdClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmLoopRecdDC,ctx,"LoopRecd",
  NULL,
  _cmDspLoopRecdAlloc,
  _cmDspLoopRecdFree,
  _cmDspLoopRecdReset,
  _cmDspLoopRecdExec,
  _cmDspLoopRecdRecv,
  NULL,NULL,
  "Loop recorder.");
  
  return &_cmLoopRecdDC;
}

enum
{
  kBypassRcId,
  kCoeffRcId,
  kInRcId,
  kOutRcId
};

cmDspClass_t _cmRectifyDC;

typedef struct
{
  cmDspInst_t  inst;
} cmDspRectify_t;

cmDspInst_t*  _cmDspRectifyAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  unsigned chs = 1;
  
  cmDspVarArg_t args[] =
  {
    { "bypass",kBypassRcId,0, 0,   kInDsvFl  | kBoolDsvFl   | kOptArgDsvFl,  "Bypass enable flag." },
    { "coeff", kCoeffRcId, 0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl,  "Coefficient" },
    { "in",    kInRcId,    0, 0,   kInDsvFl  | kAudioBufDsvFl,               "Audio input" },
    { "out",   kOutRcId,   0, chs, kOutDsvFl | kAudioBufDsvFl,               "Audio output." },
    { NULL, 0, 0, 0, 0 }
  };
  
  cmDspRectify_t* p  = cmDspInstAlloc(cmDspRectify_t,ctx,classPtr,args,instSymId,id,storeSymId,va_cnt,vl);
  
  // set default values for the parameters that were not explicitely set in the va_arg list
  cmDspSetDefaultBool(   ctx, &p->inst, kBypassRcId,0,    0 );
  cmDspSetDefaultDouble( ctx, &p->inst, kCoeffRcId, 0,  0.0 );
  
  
  return &p->inst;
}

cmDspRC_t _cmDspRectifyFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  return kOkDspRC;
}

cmDspRC_t _cmDspRectifyReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  
  rc = cmDspApplyAllDefaults(ctx,inst);
  
  return rc;  
}

cmDspRC_t _cmDspRectifyExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  unsigned          iChIdx  = 0;
  const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,kInRcId,iChIdx);
  unsigned          iSmpCnt = cmDspVarRows(inst,kInRcId);
  
  unsigned          oChIdx  = 0;
  cmSample_t*       op      = cmDspAudioBuf(ctx,inst,kOutRcId,oChIdx);
  unsigned          oSmpCnt = cmDspVarRows(inst,kOutRcId);
  
  bool              bypassFl= cmDspBool(inst,kBypassRcId);
  unsigned          n       = cmMin(iSmpCnt,oSmpCnt);
  
  unsigned          i;
  
  if( bypassFl )
    memcpy(op,ip,n*sizeof(cmSample_t));
  else
  {    
    for(i=0; i<n; ++i)
      op[i] = ip[i] > 0 ? ip[i] : 0;
  }
  
  return kOkDspRC;
}

cmDspRC_t _cmDspRectifyRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  return cmDspSetEvent(ctx,inst,evt);
}

cmDspClass_t* cmRectifyClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmRectifyDC,ctx,"Rectify",
  NULL,
  _cmDspRectifyAlloc,
  _cmDspRectifyFree,
  _cmDspRectifyReset,
  _cmDspRectifyExec,
  _cmDspRectifyRecv,
  NULL,NULL,
  "Half-wave rectifier.");
  
  return &_cmRectifyDC;
}

enum
{
  kWndMsGdId,
  kOnThreshPctGdId,
  kOnThreshDbGdId,
  kOffThreshDbGdId,
  kInGdId,
  kGateGdId,
  kRmsGdId,
  kMeanGdId
};

cmDspClass_t _cmGateDetectDC;

typedef struct
{
  cmDspInst_t  inst;
  //cmCtx*        ctx;
  cmShiftBuf*   sbp;
  cmGateDetect* gdp;
  
  
} cmDspGateDetect_t;

cmDspInst_t*  _cmDspGateDetectAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  cmDspVarArg_t args[] =
  {
    { "wnd",   kWndMsGdId,      0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Window length in milliseconds." },
    { "onpct", kOnThreshPctGdId,0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Onset slope threshold [0.0 - 1.0]." },
    { "ondb",  kOnThreshDbGdId, 0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Onset threshold dB [-Inf to 0]" },
    { "offdb", kOffThreshDbGdId,0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Offset threshold dB [-Inf to 0]" },
    { "in",    kInGdId,         0, 0,   kInDsvFl  | kAudioBufDsvFl,                 "Audio input" },
    { "gate",  kGateGdId,       0, 0,   kOutDsvFl | kBoolDsvFl,                     "Gate state output." },
    { "rms",   kRmsGdId,        0, 0,   kOutDsvFl | kDoubleDsvFl,                   "Signal level RMS"},
    { "mean",  kMeanGdId,       0, 0,   kOutDsvFl | kDoubleDsvFl,                   "Derr mean."},
    { NULL, 0, 0, 0, 0 }
  };
  
  cmDspGateDetect_t* p  = cmDspInstAlloc(cmDspGateDetect_t,ctx,classPtr,args,instSymId,id,storeSymId,va_cnt,vl);
  
  p->sbp   = cmShiftBufAlloc(ctx->cmProcCtx,NULL,0,0,0);
  p->gdp   = cmGateDetectAlloc(ctx->cmProcCtx,NULL,0,0,0,0);
  
  // set default values for the parameters that were not explicitely set in the va_arg list
  cmDspSetDefaultDouble( ctx, &p->inst, kWndMsGdId,       0,    42 );
  cmDspSetDefaultDouble( ctx, &p->inst, kOnThreshPctGdId, 0,    0.8 );
  cmDspSetDefaultDouble( ctx, &p->inst, kOnThreshDbGdId,  0,  -30.0 );
  cmDspSetDefaultDouble( ctx, &p->inst, kOffThreshDbGdId, 0,  -60.0 );
  
  return &p->inst;
}

cmDspRC_t _cmDspGateDetectFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspGateDetect_t* p = (cmDspGateDetect_t*)inst;
  cmGateDetectFree(&p->gdp);
  cmShiftBufFree(&p->sbp);
  //cmCtxFree(&ampp-&gtctx);
  return kOkDspRC;
}

cmDspRC_t _cmDspGateDetectReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspGateDetect_t* p = (cmDspGateDetect_t*)inst;
  cmDspRC_t     rc = kOkDspRC;
  
  if((rc = cmDspApplyAllDefaults(ctx,inst)) != kOkDspRC )
    return rc;
  
  double   wndMs     = cmDspDouble(inst,kWndMsGdId);
  double   sr        = cmDspSampleRate(ctx);
  unsigned wndSmpCnt = floor(wndMs * sr / 1000.0);
  
  if( cmShiftBufInit(p->sbp, cmDspSamplesPerCycle(ctx), wndSmpCnt, wndSmpCnt/4 ) != cmOkRC )
    return cmErrMsg(&ctx->cmCtx->err,kInstResetFailDspRC,"The gate detector shift buffer initialization failed.");
  
  if( cmGateDetectInit(p->gdp, cmDspSamplesPerCycle(ctx), cmDspDouble(inst,kOnThreshPctGdId), cmDspDouble(inst,kOnThreshDbGdId), cmDspDouble(inst,kOffThreshDbGdId) ) != cmOkRC )
    return cmErrMsg(&ctx->cmCtx->err,kInstResetFailDspRC,"The gate detector shift buffer initialization failed.");
  
  return rc;  
}

cmDspRC_t _cmDspGateDetectExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspGateDetect_t* p = (cmDspGateDetect_t*)inst;
  unsigned          iChIdx  = 0;
  const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,kInGdId,iChIdx);
  unsigned          iSmpCnt = cmDspVarRows(inst,kInGdId);
  
  
  while( cmShiftBufExec(p->sbp, ip, iSmpCnt ) )
  {
    cmGateDetectExec(p->gdp,p->sbp->outV, p->sbp->outN );
    
    cmDspSetDouble(ctx,inst,kRmsGdId,p->gdp->rms);
    cmDspSetDouble(ctx,inst,kMeanGdId,p->gdp->mean);
    
    if( p->gdp->deltaFl )
      cmDspSetBool(  ctx,inst,kGateGdId,p->gdp->gateFl);
    
  }
  
  return kOkDspRC;
}

cmDspRC_t _cmDspGateDetectRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t rc;
  
  if((rc = cmDspSetEvent(ctx,inst,evt)) != kOkDspRC )
    return rc;
  
  switch(evt->dstVarId)
  {
  case kWndMsGdId:
    break;
  case kOnThreshPctGdId:
    break;
  case kOnThreshDbGdId:
    break;
  case kOffThreshDbGdId:
    break;
  case kInGdId:
    break;
  }
  
  return rc;
}

cmDspClass_t* cmGateDetectClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmGateDetectDC,ctx,"GateDetect",
  NULL,
  _cmDspGateDetectAlloc,
  _cmDspGateDetectFree,
  _cmDspGateDetectReset,
  _cmDspGateDetectExec,
  _cmDspGateDetectRecv,
  NULL,NULL,
  "Gate detector.");
  
  return &_cmGateDetectDC;
}

// The purpose of this object is to calculate, store and retrieve gain coefficents
// for a set of audio channels.  The gain coefficients are designed to balance the
// volume of each channel relative to the others.  During gain calibration
// a sample of each channel is taken and it's average volume is determined.  
// After an example of all channels has been received a new set of gain coefficients
// is calculated which decreases the volume of loud channels and increases the
// volume of quiet channels.
//
//  The gain coefficents are made available via a set of 'gain-###' output ports.
//
//  This object acts as an interface to the cmAutoGain processor.  
//
//  As input it takes a channel configuration JSON file of the form:
//  {
//    ch_array : 
//    [ [&quotch&quot,&quotssi&quot,&quotpitch&quot,&quotmidi&quot,&quotgain&quot]
//      [ 0,    0,    &quotC4&quot,   60,    1.0 ]
//               ....
//      [ n     0,    &quotC5&quot,   72,    1.0 ]
//    ] 
//  }      
//
//  Each array in 'ch_array' gives the configuration of a channel.
//  
//
//  It also requires a JSON resource object of the form
//    gdParms: 
//    {
//      medCnt: 5                   
//      avgCnt: 9       
//      suprCnt: 6       
//      offCnt: 3       
//      suprCoeff: 1.400000       
//      onThreshDb: -53.000000       
//      offThreshDb: -80.000000       
//    }    
//
//    These arguments are used to configure the cmAutoGain Proessor gate detector function.
//
//  During runtime the object accepts the following action selector symbol id's:
//    a. start  - begin a new calibration  session 
//    b. proc   - end a calibration session and calculate new gain coeff's
//    c. cancel - cancel a calibration session   
//    d. write  - write the channel configuration file 
//    e. print  - print the current auto gain calibration state
//
//  After a 'start' msg the object accepts channel id's throught its 'id' input port.
//  Each 'id' identifies the channel which it will process next.
//  Upon reception of a channel id the object routes subsequent audio to its
//  internal cmAutoGain processor until it receives the next channel id 
//  or a 'proc' or 'cancel' symbol.


 enum
{
  kChCntAgId,
  kHopAgId,
  kMedNAgId,
  kAvgNAgId,
  kSupNAgId,
  kOffNAgId,
  kSupCoefAgId,
  kOnThrAgId,
  kOffThrAgId,
  kSelAgId,
  kIdAgId,
  kInBaseAgId
};

typedef struct
{
  cmDspInst_t        inst;
  cmAutoGain*        agp;
  unsigned           gainBaseAgId;
  unsigned           chCnt;
  unsigned           chIdx;
  unsigned           startSymId;
  unsigned           procSymId;
  unsigned           cancelSymId;
  unsigned           writeSymId;
  unsigned           printSymId;
} cmDspAutoGain_t;

cmDspClass_t _cmAutoGainDC;

cmDspInst_t*  _cmDspAutoGainAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  cmDspVarArg_t args[] =
  {
    { "chCnt",kChCntAgId,  0, 0,  kUIntDsvFl   | kReqArgDsvFl, "Audio channel count."},  
    { "hop",  kHopAgId,    0, 0,  kDoubleDsvFl | kReqArgDsvFl, "RMS hop in milliseconds."},
    { "med",  kMedNAgId,   0, 0,  kUIntDsvFl   | kReqArgDsvFl, "Median filter hop count."},
    { "avg",  kAvgNAgId,   0, 0,  kUIntDsvFl   | kReqArgDsvFl, "Average filter hop count."},
    { "sup",  kSupNAgId,   0, 0,  kUIntDsvFl   | kReqArgDsvFl, "Supression filter hop count."},
    { "off",  kOffNAgId,   0, 0,  kUIntDsvFl   | kReqArgDsvFl, "Offset filter hop count."},
    { "supC", kSupCoefAgId,0, 0,  kInDsvFl     | kDoubleDsvFl | kReqArgDsvFl, "Suppression coefficent."},
    { "onThr",kOnThrAgId,  0, 0,  kInDsvFl     | kDoubleDsvFl | kReqArgDsvFl, "Onset threshold in dB."},
    { "offThr",kOffThrAgId,0, 0,  kInDsvFl     | kDoubleDsvFl | kReqArgDsvFl, "Offset threshold in dB."},
    { "sel",  kSelAgId,    0, 0,  kInDsvFl     | kSymDsvFl    | kNoArgDsvFl,  "Action Selector: start | proc | cancel." },
    { "id",   kIdAgId,     0, 0,  kInDsvFl     | kIntDsvFl    | kNoArgDsvFl,  "Channel id input."},
  };
  
  va_list             vl1;
  unsigned            i;
  
  
  // verify that at least one var arg exists
  if( va_cnt < 1 )
  {
    cmDspClassErr(ctx,classPtr,kInvalidArgDspRC,"The AutoGain constructor must be given the audio channel count as its first argument.");
    return NULL;
  }    
  // copy the va_list so that it can be used again in cmDspInstAlloc()
  va_copy(vl1,vl);
  
  // get the first var arg which should be a filename
  unsigned chCnt = va_arg(vl,unsigned);
  
  if( chCnt == 0 )
  {
    cmDspClassErr(ctx,classPtr,kInvalidArgDspRC,"The AutoGain constructor requires at least 1 audio channel.");
    va_end(vl1);
    return NULL;
  }
  
  unsigned fixArgCnt    = sizeof(args)/sizeof(args[0]);
  unsigned argCnt       = fixArgCnt + 2 * chCnt;
  unsigned gainBaseAgId = kInBaseAgId + chCnt;
  cmDspVarArg_t a[ argCnt+1 ];
  
  assert( fixArgCnt == kInBaseAgId );
  
  // setup the output gain args 
  cmDspArgCopy(       a, argCnt, 0, args, fixArgCnt );
  cmDspArgSetupN(ctx, a, argCnt, kInBaseAgId,  chCnt, "in",   kInBaseAgId,  0, 0, kInDsvFl  | kAudioBufDsvFl, "audio in");
  cmDspArgSetupN(ctx, a, argCnt, gainBaseAgId, chCnt, "gain", gainBaseAgId, 0, 0, kOutDsvFl | kDoubleDsvFl,   "calibrated channel gain");
  cmDspArgSetupNull(  a+argCnt);  // set terminating arg. flag
  
  // instantiate the object
  cmDspAutoGain_t* p  = cmDspInstAlloc(cmDspAutoGain_t,ctx,classPtr,a,instSymId,id,storeSymId,va_cnt,vl1);
  
  // assign the current gain coefficients
  for(i=0; i<chCnt; ++i)
    cmDspSetDefaultDouble( ctx, &p->inst, gainBaseAgId + i, 0.0, 1.0);
  
  
  // allocate the auto gain calculation proc
  p->agp         = cmAutoGainAlloc(ctx->cmProcCtx,NULL,0,0,0,0,NULL);
  p->chCnt       = chCnt;
  p->chIdx       = cmInvalidIdx;
  p->gainBaseAgId= gainBaseAgId;
  p->startSymId  = cmSymTblRegisterStaticSymbol(ctx->stH,"start");
  p->procSymId   = cmSymTblRegisterStaticSymbol(ctx->stH,"proc");
  p->cancelSymId = cmSymTblRegisterStaticSymbol(ctx->stH,"cancel");
  p->printSymId  = cmSymTblRegisterStaticSymbol(ctx->stH,"print");
  
  cmDspSetDefaultSymbol( ctx, &p->inst, kSelAgId, p->cancelSymId );
  cmDspSetDefaultInt(    ctx, &p->inst, kIdAgId,  0, cmInvalidId );
  
  va_end(vl1);
  
  return &p->inst;
}


cmDspRC_t _cmDspAutoGainFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspAutoGain_t* p = (cmDspAutoGain_t*)inst;
  
  cmAutoGainFree(&p->agp);
  
  return kOkDspRC;
}

cmDspRC_t _cmDspAutoGainReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc = kOkDspRC;
  
  rc = cmDspApplyAllDefaults(ctx,inst);
  
  
  return rc;  
}

cmDspRC_t _cmDspAutoGainExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspAutoGain_t* p = (cmDspAutoGain_t*)inst;
  
  unsigned curInChIdx = cmDspInt( inst, kIdAgId);
  
  if( cmDspSymbol( inst, kSelAgId ) == p->startSymId && curInChIdx != cmInvalidId )
  {
    unsigned          inChVarId  = kInBaseAgId+curInChIdx;
    const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,inChVarId,0);
    unsigned          iSmpCnt = cmDspVarRows(inst,inChVarId);
    
    cmAutoGainProcCh( p->agp, ip, iSmpCnt );
  }
  
  return kOkDspRC;
}

cmDspRC_t _cmDspAutoGainInit( cmDspCtx_t* ctx, cmDspInst_t* inst )
{
  cmDspAutoGain_t* p  = (cmDspAutoGain_t*)inst;  
  cmGateDetectParams gd;
  unsigned i;
  
  // collect the params into a cmGateDetectParams recd
  gd.medCnt      = cmDspUInt(   inst, kMedNAgId );
  gd.avgCnt      = cmDspUInt(   inst, kAvgNAgId );
  gd.suprCnt     = cmDspUInt(   inst, kSupNAgId );
  gd.offCnt      = cmDspUInt(   inst, kOffNAgId );
  gd.suprCoeff   = cmDspDouble( inst, kSupCoefAgId );
  gd.onThreshDb  = cmDspDouble( inst, kOnThrAgId );
  gd.offThreshDb = cmDspDouble( inst, kOffThrAgId );
  
  // setup the internal auto-gain object
  if( cmAutoGainInit(p->agp, cmDspSamplesPerCycle(ctx), cmDspSampleRate(ctx), cmDspDouble(inst,kHopAgId), p->chCnt, &gd ) != cmOkRC )
    return cmDspInstErr(ctx,inst,kSubSysFailDspRC,"The internal auto-gain instance could not be initialized.");
  
  // send out gain's of 1.0 so that the input audio is not 
  // biased by any existing scaling.  
  for(i=0; i<p->chCnt; ++i)
    cmDspSetDouble( ctx, inst, p->gainBaseAgId+i, 1.0);
  
  return kOkDspRC;
}

cmDspRC_t _cmDspAutoGainRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspAutoGain_t* p  = (cmDspAutoGain_t*)inst;
  cmDspRC_t          rc = kOkDspRC;
  
  switch( evt->dstVarId )
  {
  case kSelAgId:
    {
      // store the current 'sel' state
      unsigned prvSymId = cmDspSymbol(inst,kSelAgId);
      
      // update it 'sel' to the new state
      cmDspSetEvent(ctx,inst,evt);
      
      // get the new state
      unsigned newSymId = cmDspSymbol(inst,kSelAgId);
      
      //
      // if PRINTing was requested
      //      
      if( newSymId == p->printSymId )
      {
        cmRptPrintf(&ctx->cmCtx->rpt,"Auto-Gain Report\n");
        cmAutoGainPrint( p->agp, &ctx->cmCtx->rpt );
        goto doneLabel;
      }
      
      
      //
      // if calibration was CANCELLED
      //      
      if( newSymId == p->cancelSymId )
      {
        cmDspSetInt( ctx, inst, kIdAgId, cmInvalidId );
        cmRptPrintf(&ctx->cmCtx->rpt,"cancelled\n");
        goto doneLabel;
      }
      
      //
      // if calibration STARTup was requested - initialize the autogain proc 
      //      
      if( newSymId == p->startSymId )
      {
        _cmDspAutoGainInit(ctx,inst);
        cmRptPrintf(&ctx->cmCtx->rpt,"started\n");
        goto doneLabel;
      }
      
      //
      // if calibration PROCessing was requested
      //      
      if( newSymId == p->procSymId && prvSymId == p->startSymId )
      {
        cmRptPrintf(&ctx->cmCtx->rpt,"proc\n");
        
        // set the current channel id to 'cmInvalidId' to stop calls to 
        // cmAutoGainProcCh() in _cmDspAutoGainExec()        
        cmDspSetInt( ctx, inst, kIdAgId, cmInvalidId );
        
        // update the auto gain coefficients
        if( cmAutoGainCalcGains(p->agp) == cmOkRC )
        {
          // send the new auto gain coefficients to the output ports
          unsigned i;
          for(i=0; i<p->chCnt; ++i)
            cmDspSetDouble( ctx, inst, p->gainBaseAgId+i, p->agp->chArray[i].gain);
        }
        
        goto doneLabel;
      }
    }
    break;
    
  case kIdAgId:
    cmDspSetEvent(ctx,inst,evt);
    if( cmDspSymbol(inst,kSelAgId) == p->startSymId )
    {
      cmRptPrintf(&ctx->cmCtx->rpt,"id:%i\n", cmDspInt(inst,kIdAgId));
      cmAutoGainStartCh(p->agp, p->chIdx = cmDspInt(inst,kIdAgId));
    }
    break;
    
  default:
    { assert(0); }
  }
  
  doneLabel:
  return rc;
}

cmDspClass_t* cmAutoGainClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmAutoGainDC,ctx,"AutoGain",
  NULL,
  _cmDspAutoGainAlloc,
  _cmDspAutoGainFree,
  _cmDspAutoGainReset,
  _cmDspAutoGainExec,
  _cmDspAutoGainRecv,
  NULL,NULL,
  "Auto-gain calibrator.");
  
  return &_cmAutoGainDC;
}

enum
{
  kHopMsEfId,      // RMS window length in milliseconds
  kMedCntEfId,     
  kAvgCntEfId,     
  kSuprCntEfId,    
  kOffCntEfId,     
  kSuprCoefEfId,  
  kOnThrDbEfId,    
  kOffThrDbEfId,   
  kMaxDbEfId,
  kInEfId,     
  kGateEfId,
  kRmsEfId,
  kLevelEfId,
  kOnEfId,
  kOffEfId
};

cmDspClass_t _cmEnvFollowDC;

typedef struct
{
  cmDspInst_t    inst;
  cmShiftBuf*    sbp;
  cmGateDetect2* gdp;
} cmDspEnvFollow_t;

cmDspInst_t*  _cmDspEnvFollowAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  cmDspVarArg_t args[] =
  {
    { "wnd",   kHopMsEfId,      0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "RMS Window length"},
    { "med",   kMedCntEfId,     0, 0,   kInDsvFl  | kUIntDsvFl     | kOptArgDsvFl,  "Median filter length." },
    { "avg",   kAvgCntEfId,     0, 0,   kInDsvFl  | kUIntDsvFl     | kOptArgDsvFl,  "Averaging filter length." },
    { "sup",   kSuprCntEfId,    0, 0,   kInDsvFl  | kUIntDsvFl     | kOptArgDsvFl,  "Supression filter length." },
    { "off",   kOffCntEfId,     0, 0,   kInDsvFl  | kUIntDsvFl     | kOptArgDsvFl,  "Offset detection window length" },
    { "supc",  kSuprCoefEfId,   0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Suppression shape coefficient" },
    { "ondb",  kOnThrDbEfId,    0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Onset threshold dB." },
    { "offdb", kOffThrDbEfId,   0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Offset threshold dB" },
    { "maxdb", kMaxDbEfId,      0, 0,   kInDsvFl  | kDoubleDsvFl   | kOptArgDsvFl,  "Max reference dB" },
    { "in",    kInEfId,         0, 0,   kInDsvFl  | kAudioBufDsvFl,                 "Audio input" },
    { "gate",  kGateEfId,       0, 0,   kOutDsvFl | kBoolDsvFl,                     "Gate state output." },
    { "rms",   kRmsEfId,        0, 0,   kOutDsvFl | kDoubleDsvFl,                   "Signal level RMS"},
    { "level", kLevelEfId,      0, 0,   kOutDsvFl | kDoubleDsvFl,                   "Signal level 0.0-1.0 as scale between offset thresh dB and max dB"},
    { "ons",   kOnEfId,         0, 0,   kOutDsvFl | kUIntDsvFl,                     "Onset counter"},
    { "offs",  kOffEfId,        0, 0,   kOutDsvFl | kUIntDsvFl,                     "Offset counter"},
    { NULL, 0, 0, 0, 0 }
  };
  
  cmDspEnvFollow_t* p  = cmDspInstAlloc(cmDspEnvFollow_t,ctx,classPtr,args,instSymId,id,storeSymId,va_cnt,vl);
  
  p->sbp   = cmShiftBufAlloc(ctx->cmProcCtx,NULL,0,0,0);
  p->gdp   = cmGateDetectAlloc2(ctx->cmProcCtx,NULL,0,NULL);
  
  // set default values for the parameters that were not explicitely set in the va_arg list
  cmDspSetDefaultDouble( ctx, &p->inst, kHopMsEfId,       0,     12 );
  cmDspSetDefaultUInt(   ctx, &p->inst, kMedCntEfId,      0,      5 );
  cmDspSetDefaultUInt(   ctx, &p->inst, kAvgCntEfId,      0,      9 );
  cmDspSetDefaultUInt(   ctx, &p->inst, kSuprCntEfId,     0,      6 );
  cmDspSetDefaultUInt(   ctx, &p->inst, kOffCntEfId,      0,      3 );
  cmDspSetDefaultDouble( ctx, &p->inst, kSuprCoefEfId,    0,    1.4 );
  cmDspSetDefaultDouble( ctx, &p->inst, kOnThrDbEfId,     0,    -45 );
  cmDspSetDefaultDouble( ctx, &p->inst, kOffThrDbEfId,    0,    -80 );
  cmDspSetDefaultDouble( ctx, &p->inst, kMaxDbEfId,       0,    -10.0 );
  cmDspSetDefaultUInt(   ctx, &p->inst, kOnEfId,          0,      0 );
  cmDspSetDefaultUInt(   ctx, &p->inst, kOffEfId,         0,      0 );
  
  return &p->inst;
}

cmDspRC_t _cmDspEnvFollowFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspEnvFollow_t* p = (cmDspEnvFollow_t*)inst;
  cmGateDetectFree2(&p->gdp);
  cmShiftBufFree(&p->sbp);
  return kOkDspRC;
}

cmDspRC_t _cmDspEnvFollowReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspEnvFollow_t* p = (cmDspEnvFollow_t*)inst;
  cmDspRC_t     rc = kOkDspRC;
  
  if((rc = cmDspApplyAllDefaults(ctx,inst)) != kOkDspRC )
    return rc;
  
  cmGateDetectParams r;
  r.medCnt      = cmDspUInt(   inst, kMedCntEfId );
  r.avgCnt      = cmDspUInt(   inst, kAvgCntEfId );
  r.suprCnt     = cmDspUInt(   inst, kSuprCntEfId );
  r.offCnt      = cmDspUInt(   inst, kOffCntEfId );
  r.suprCoeff   = cmDspDouble( inst, kSuprCoefEfId );
  r.onThreshDb  = cmDspDouble( inst, kOnThrDbEfId );
  r.offThreshDb = cmDspDouble( inst, kOffThrDbEfId );
  
  double   sr        = cmDspSampleRate(ctx);
  double   hopSmpCnt = floor(sr * cmDspDouble(inst,kHopMsEfId) / 1000 );
  unsigned wndSmpCnt = floor(r.medCnt * hopSmpCnt);
  
  if( cmShiftBufInit(p->sbp, cmDspSamplesPerCycle(ctx), wndSmpCnt, hopSmpCnt ) != cmOkRC )
    return cmDspInstErr(ctx,inst,kInstResetFailDspRC,"The gate detector shift buffer initialization failed.");
  
  if( cmGateDetectInit2(p->gdp, cmDspSamplesPerCycle(ctx), &r ) != cmOkRC )
    return cmDspInstErr(ctx,inst,kInstResetFailDspRC,"The gate detector shift buffer initialization failed.");
  
  return rc;  
}

cmDspRC_t _cmDspEnvFollowExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspEnvFollow_t* p       = (cmDspEnvFollow_t*)inst;
  unsigned          iChIdx  = 0;
  const cmSample_t* ip      = cmDspAudioBuf(ctx,inst,kInEfId,iChIdx);
  unsigned          iSmpCnt = cmDspVarRows(inst,kInEfId);
  double            maxDb   = cmDspDouble(inst,kMaxDbEfId);
  double            offDb   = cmDspDouble(inst,kOffThrDbEfId);
  
  while( cmShiftBufExec(p->sbp, ip, iSmpCnt ) )
  {
    cmGateDetectExec2(p->gdp,p->sbp->outV, p->sbp->outN );
    
    // RMS is going out at the audio rate - maybe there should be an option
    // to send it only when the gate changes - this could significantly 
    // cut down on unnecessary transmission if the RMS is only used 
    // when the gate changes    
    cmDspSetDouble(ctx,inst,kRmsEfId, p->gdp->rms );
    
    double rmsDb = p->gdp->rms <  0.00001 ? -100.0 : 20.0 * log10(p->gdp->rms);
    double level = maxDb       <= offDb   ?      0 : fabs((offDb - cmMax( offDb, cmMin( maxDb, rmsDb ))) / (maxDb - offDb));
    
    cmDspSetDouble(ctx,inst,kLevelEfId, level );
    
    if( p->gdp->onFl || p->gdp->offFl )
    {
      cmDspSetBool(ctx, inst, kGateEfId, p->gdp->gateFl);    
      
      if( p->gdp->onFl )
        cmDspSetUInt( ctx, inst, kOnEfId, cmDspUInt(inst,kOnEfId) + 1 );
      
      if( p->gdp->offFl )
        cmDspSetUInt( ctx, inst, kOffEfId, cmDspUInt(inst,kOffEfId) + 1 );
    }
  }
  
  return kOkDspRC;
}

cmDspRC_t _cmDspEnvFollowRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t rc;
  cmDspEnvFollow_t* p = (cmDspEnvFollow_t*)inst;
  
  if((rc = cmDspSetEvent(ctx,inst,evt)) == kOkDspRC )
  {
    switch( evt->dstVarId )
    {
    case kOnThrDbEfId:
      cmGateDetectSetOnThreshDb2(p->gdp, cmDspDouble(inst,kOnThrDbEfId) );
      break;
      
    case kOffThrDbEfId:
      cmGateDetectSetOffThreshDb2(p->gdp, cmDspDouble(inst,kOffThrDbEfId) );
      break;
    }
    
  }
  return rc;
}

cmDspClass_t* cmEnvFollowClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmEnvFollowDC,ctx,"EnvFollow",
  NULL,
  _cmDspEnvFollowAlloc,
  _cmDspEnvFollowFree,
  _cmDspEnvFollowReset,
  _cmDspEnvFollowExec,
  _cmDspEnvFollowRecv,
  NULL,NULL,
  "Envelope follower and gate detector.");
  
  return &_cmEnvFollowDC;
}

// Fade in and out an arbitrary number of audio signals based on gate signals.
// When the gate is high the signal fades in and when the gate is low the signal fades out.
// Constructor Args:
//    Required: Count of input and output channels.
//    Optional: Fade time in milliseconds.
//
// Inputs:
//    bool   Control gates
//    audio  Input audio.
// Outputs:
//    audio  Output audio
//    double Channel gains.

enum
{
  kChCntXfId,
  kFadeTimeMsXfId,
  kMstrGateXfId,
  kFadeInTimeMsXfId,
  kFadeOutTimeMsXfId,
  kResetXfId,
  kOnXfId,
  kOffXfId,
  kGateBaseXfId,
};

cmDspClass_t _cmXfaderDC;

typedef struct
{
  cmDspInst_t  inst;
  cmXfader*    xfdp;
  unsigned     inBaseXfId;
  unsigned     outBaseXfId;
  unsigned     stateBaseXfId;
  unsigned     gainBaseXfId;
  unsigned     chCnt;
  bool*        chGateV;
  unsigned     onSymId;
  unsigned     offSymId;
} cmDspXfader_t;

cmDspInst_t*  _cmDspXfaderAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  cmDspVarArg_t args[] =
  {
    { "chs",   kChCntXfId,         0, 0,               kUIntDsvFl   | kReqArgDsvFl, "Input and Output channel count"},
    { "ms",    kFadeTimeMsXfId,    0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl, "Fade time in milliseonds."},
    { "mgate", kMstrGateXfId,      0, 0,   kInDsvFl  | kBoolDsvFl   | kOptArgDsvFl, "Master gate - can be used to set all gates."},
    { "ims",   kFadeInTimeMsXfId,  0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl, "Fade in time in milliseonds."},
    { "oms",   kFadeOutTimeMsXfId, 0, 0,   kInDsvFl  | kDoubleDsvFl | kOptArgDsvFl, "Fade out time in milliseonds."},
    { "reset", kResetXfId,         0, 0,   kInDsvFl  | kBoolDsvFl,                  "Jump to gate states rather than fade."},
    { "on",    kOnXfId,            0, 0,   kOutDsvFl | kSymDsvFl,                   "Send 'on' when all ch's transition from off to on."},
    { "off",   kOffXfId,           0, 0,   kOutDsvFl | kSymDsvFl,                   "Send 'off' when all ch's transition from on to off."},
  };
  
  if( va_cnt < 1 )
  {
    cmDspClassErr(ctx,classPtr,kInvalidArgDspRC,"The Xfader object must be given a channel count argument.");
    return NULL;
  }
  
  va_list vl1;
  va_copy(vl1,vl);
  
  unsigned chCnt         = va_arg(vl,int);
  unsigned fixArgCnt     = sizeof(args)/sizeof(args[0]);
  unsigned argCnt        = fixArgCnt + 5*chCnt;
  unsigned inBaseXfId    = kGateBaseXfId + chCnt;
  unsigned outBaseXfId   = inBaseXfId + chCnt;
  unsigned stateBaseXfId = outBaseXfId + chCnt;
  unsigned gainBaseXfId  = stateBaseXfId + chCnt;
  cmDspVarArg_t a[ argCnt+1 ];
  
  
  // setup the input gate detectors and the output gain args 
  cmDspArgCopy(  a, argCnt, 0, args, fixArgCnt );
  cmDspArgSetupN(ctx, a, argCnt, kGateBaseXfId, chCnt, "gate", kGateBaseXfId, 0, 0, kInDsvFl  | kBoolDsvFl,     "gate flags");
  cmDspArgSetupN(ctx, a, argCnt, inBaseXfId,    chCnt, "in",   inBaseXfId,    0, 0, kInDsvFl  | kAudioBufDsvFl, "audio input");
  cmDspArgSetupN(ctx, a, argCnt, outBaseXfId,   chCnt, "out",  outBaseXfId,   0, 1, kOutDsvFl | kAudioBufDsvFl, "audio output"); 
  cmDspArgSetupN(ctx, a, argCnt, stateBaseXfId, chCnt, "state",stateBaseXfId, 0, 0, kOutDsvFl | kBoolDsvFl,     "current fader state"); 
  cmDspArgSetupN(ctx, a, argCnt, gainBaseXfId,  chCnt, "gain", gainBaseXfId,  0, 0, kOutDsvFl | kDoubleDsvFl,   "gain output"); 
  cmDspArgSetupNull( a+argCnt);  // set terminating arg. flag
  
  cmDspXfader_t* p  = cmDspInstAlloc(cmDspXfader_t,ctx,classPtr,a,instSymId,id,storeSymId,va_cnt,vl1);
  
  double fadeTimeMs = cmDspDouble(&p->inst, kFadeTimeMsXfId );
  p->xfdp           = cmXfaderAlloc(ctx->cmProcCtx,NULL,cmDspSampleRate(ctx), chCnt, fadeTimeMs);
  p->inBaseXfId     = inBaseXfId;
  p->outBaseXfId    = outBaseXfId;
  p->stateBaseXfId  = stateBaseXfId;
  p->gainBaseXfId   = gainBaseXfId;
  p->chCnt          = chCnt;
  p->chGateV        = cmMemAllocZ(bool,p->chCnt);
  p->onSymId        = cmSymTblRegisterStaticSymbol(ctx->stH,"on");
  p->offSymId       = cmSymTblRegisterStaticSymbol(ctx->stH,"off");
  
  // set default values for the parameters that were not explicitely set in the va_arg list
  cmDspSetDefaultDouble( ctx, &p->inst, kFadeTimeMsXfId,  0,     100 );
  cmDspSetDefaultBool(   ctx, &p->inst, kMstrGateXfId,    false, false);
  cmDspSetDefaultSymbol( ctx, &p->inst, kOnXfId,    p->onSymId );
  cmDspSetDefaultSymbol( ctx, &p->inst, kOffXfId,   p->offSymId );  
  
  int i;
  for(i=0; i<chCnt; ++i)
    cmDspSetDefaultBool( ctx, &p->inst, stateBaseXfId+i, false, false );
  
  va_end(vl1);
  
  return &p->inst;
}

cmDspRC_t _cmDspXfaderFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspXfader_t* p = (cmDspXfader_t*)inst;
  cmMemFree(p->chGateV);
  cmXfaderFree(&p->xfdp);
  return kOkDspRC;
}

cmDspRC_t _cmDspXfaderReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t      rc = kOkDspRC;
  rc = cmDspApplyAllDefaults(ctx,inst);
  
  cmDspXfader_t* p  = (cmDspXfader_t*)inst;
  
  // TODO: zeroing of output audio buffers should be built into cmDspApplyAllDefaults().
  unsigned i;
  for(i=0; i<p->chCnt; ++i)
    cmDspZeroAudioBuf(ctx,inst,p->outBaseXfId + i);
  
  return rc;  
}

cmDspRC_t _cmDspXfaderExec(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t      rc = cmOkRC;
  cmDspXfader_t* p  = (cmDspXfader_t*)inst;
  unsigned       i;
  
  // update the internal cross fader by providing it with new gate settings and generate new gain values
  cmXfaderExec( p->xfdp, cmDspSamplesPerCycle(ctx), p->chGateV, p->chCnt );
  
  for(i=0; i<p->chCnt; ++i)
  {
    unsigned          n  = cmDspAudioBufSmpCount(ctx,inst,p->outBaseXfId+i,0);
    cmSample_t*       op = cmDspAudioBuf(ctx,inst,p->outBaseXfId+i,0);
    const cmSample_t* ip = cmDspAudioBuf(ctx,inst,p->inBaseXfId+i,0);
    cmSample_t        gain = (cmSample_t)p->xfdp->chArray[i].ep_gain;
    
    if( op != NULL )
    {
      if( ip == NULL )
        cmVOS_Zero(op,n);
      else
        cmVOS_MultVVS(op,n,ip,gain);
    }
    
    if( p->xfdp->chArray[i].onFl )
    {
      cmDspSetBool(ctx,inst,p->stateBaseXfId+i,true);
    }
    
    if( p->xfdp->chArray[i].offFl )
    {
      cmDspSetBool(ctx,inst,p->stateBaseXfId+i,false);
    }
    
    // send the gain output
    cmDspSetDouble(ctx,inst,p->gainBaseXfId+i,gain);
    
  }
  
  if( p->xfdp->onFl )
    cmDspSetSymbol(ctx,inst,kOnXfId,p->onSymId);
  
  if( p->xfdp->offFl )
    cmDspSetSymbol(ctx,inst,kOffXfId,p->offSymId);
  
  return rc;
}

cmDspRC_t _cmDspXfaderRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t rc;
  cmDspXfader_t* p = (cmDspXfader_t*)inst;
  
  if((rc = cmDspSetEvent(ctx,inst,evt)) != kOkDspRC )
    return rc;
  
  switch( evt->dstVarId )
  {
  case kFadeTimeMsXfId:
    // if this is an xfade time event then transfer the new xfade time to the xfade proc
    cmXfaderSetXfadeTime(p->xfdp,cmDspDouble(inst,kFadeTimeMsXfId));
    break;
    
  case kMstrGateXfId:
    {
      bool fl = cmDspBool(inst,kMstrGateXfId);
      unsigned i;
      for(i=0; i<p->chCnt; ++i)
        p->chGateV[i] = fl;
    }
    break;
    
  case kFadeInTimeMsXfId:
    cmXfaderSetXfadeInTime(p->xfdp,cmDspDouble(inst,kFadeInTimeMsXfId));
    break;
    
  case kFadeOutTimeMsXfId:
    cmXfaderSetXfadeOutTime(p->xfdp,cmDspDouble(inst,kFadeOutTimeMsXfId));
    break;
    
  case kResetXfId:
    {
      cmXfaderExec( p->xfdp, cmDspSamplesPerCycle(ctx), p->chGateV, p->chCnt );
      cmXfaderJumpToDestinationGain(p->xfdp);
      // force the chGateV[] to match the xfaders state
      int i;
      for(i=0; i<p->chCnt; ++i)
      {
        bool gateFl = p->xfdp->chArray[i].gateFl;
        p->chGateV[i] = gateFl;
        cmDspSetBool(  ctx,inst,p->stateBaseXfId + i, gateFl);
        cmDspSetDouble(ctx,inst,p->gainBaseXfId  + i, gateFl ? 1.0 : 0.0 );          
      }
    }
    break;
    
  }
  
  // record gate changes into p-&gtchGateV[] for later use in _cmDspXfaderExec().
  if( kGateBaseXfId <= evt->dstVarId && evt->dstVarId < kGateBaseXfId + p->chCnt )
  {
    p->chGateV[ evt->dstVarId - kGateBaseXfId ] = cmDspBool( inst, evt->dstVarId );
  }
  
  return rc;
}

cmDspClass_t* cmXfaderClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmXfaderDC,ctx,"Xfader",
  NULL,
  _cmDspXfaderAlloc,
  _cmDspXfaderFree,
  _cmDspXfaderReset,
  _cmDspXfaderExec,
  _cmDspXfaderRecv,
  NULL,NULL,
  "Cross fade gain generator.");
  
  return &_cmXfaderDC;
}

enum
{
  kFnCcId,
  kSelCcId,
  kDoneCcId,
  kGainBaseCcId
};

cmDspClass_t _cmChCfgDC;

typedef struct
{
  cmDspInst_t  inst;
  cmChCfg*     ccp;
  unsigned     midiBaseCcId;
  unsigned     hzBaseCcId;
  unsigned     chBaseCcId;
  unsigned     nsflBaseCcId;
  unsigned     nshzBaseCcId;
  unsigned     printSymId;
  unsigned     writeSymId;
  unsigned     nsCmdSymId;
  unsigned     hzCmdSymId;
  unsigned     resetSymId;
} cmDspChCfg_t;

cmDspInst_t*  _cmDspChCfgAlloc(cmDspCtx_t* ctx, cmDspClass_t* classPtr, unsigned storeSymId, unsigned instSymId, unsigned id, unsigned va_cnt, va_list vl )
{
  cmDspVarArg_t args[] =
  {
    { "fn",   kFnCcId,  0, 0,               kStrzDsvFl| kReqArgDsvFl, "Channel configuration JSON file name."},
    { "sel",  kSelCcId, 0, 0,   kInDsvFl  | kSymDsvFl,                "Action selector: print | write | ns | reset"},
    { "done", kDoneCcId,0, 0,   kOutDsvFl | kSymDsvFl,                "Trigger following action."}
  };
  
  if( va_cnt < 1 )
  {
    cmDspClassErr(ctx,classPtr,kInvalidArgDspRC,"The channel configuration object must be given a file name argument.");
    return NULL;
  }
  
  va_list vl1;
  va_copy(vl1,vl);
  
  const cmChar_t* chCfgFn = va_arg(vl,cmChar_t*);
  
  cmChCfg* ccp = cmChCfgAlloc( ctx->cmProcCtx, NULL, ctx->cmCtx, chCfgFn );
  
  if( ccp == NULL || ccp->chCnt==0 )
  {
    cmDspClassErr(ctx,classPtr,kInvalidArgDspRC,"The channel configuration object could not be initialized with the file name '%s'.",cmStringNullGuard(chCfgFn));
    return NULL;
  }
  
  unsigned       chCnt         = ccp->chCnt;
  unsigned       nsChCnt       = ccp->nsChCnt;
  unsigned       fixArgCnt     = sizeof(args)/sizeof(args[0]);
  unsigned       argCnt        = fixArgCnt + 5*chCnt + nsChCnt;
  unsigned       midiBaseCcId  = kGainBaseCcId + chCnt;
  unsigned       hzBaseCcId    = midiBaseCcId  + chCnt;
  unsigned       chBaseCcId    = hzBaseCcId    + chCnt;
  unsigned       nsflBaseCcId  = chBaseCcId    + chCnt;
  unsigned       nshzBaseCcId  = nsflBaseCcId  + chCnt;
  cmDspChCfg_t*  p             = NULL;
  cmDspVarArg_t  a[ argCnt+1 ];
  unsigned       i,j;
  
  // setup the input gate detectors and the output gain args 
  cmDspArgCopy(  a, argCnt, 0, args, fixArgCnt );
  cmDspArgSetupN(ctx, a, argCnt, kGainBaseCcId, chCnt,   "gain",  kGainBaseCcId, 0, 0, kSendDfltDsvFl | kInDsvFl   | kOutDsvFl | kDoubleDsvFl,  "Gain input and output.");
  cmDspArgSetupN(ctx, a, argCnt, midiBaseCcId,  chCnt,   "midi",  midiBaseCcId,  0, 0, kSendDfltDsvFl | kOutDsvFl  | kUIntDsvFl,                "MIDI pitch output");
  cmDspArgSetupN(ctx, a, argCnt, hzBaseCcId,    chCnt,   "hz",    hzBaseCcId,    0, 0, kSendDfltDsvFl | kOutDsvFl  | kDoubleDsvFl,              "pitch output in Hz");
  cmDspArgSetupN(ctx, a, argCnt, chBaseCcId,    chCnt,   "ch",    chBaseCcId,    0, 0, kSendDfltDsvFl | kOutDsvFl  | kUIntDsvFl  ,              "Audio channel index");
  cmDspArgSetupN(ctx, a, argCnt, nsflBaseCcId,  chCnt,   "nsfl",  nsflBaseCcId,  0, 0,                  kOutDsvFl  | kBoolDsvFl,                "noise shaper enables");
  cmDspArgSetupN(ctx, a, argCnt, nshzBaseCcId,  nsChCnt, "nshz",  nshzBaseCcId,  0, 0,                  kOutDsvFl  | kDoubleDsvFl,              "noise-shaper pitch output in Hz");
  cmDspArgSetupNull( a+argCnt);  // set terminating arg. flag
  
  if((p = cmDspInstAlloc(cmDspChCfg_t,ctx,classPtr,a,instSymId,id,storeSymId,va_cnt,vl1)) == NULL )
    return NULL;
  
  p->ccp           = ccp;
  p->midiBaseCcId  = midiBaseCcId;
  p->hzBaseCcId    = hzBaseCcId;
  p->chBaseCcId    = chBaseCcId;
  p->nsflBaseCcId  = nsflBaseCcId;
  p->nshzBaseCcId  = nshzBaseCcId;
  p->writeSymId    = cmSymTblRegisterStaticSymbol(ctx->stH,"write");
  p->printSymId    = cmSymTblRegisterStaticSymbol(ctx->stH,"print");
  p->nsCmdSymId    = cmSymTblRegisterStaticSymbol(ctx->stH,"ns");
  p->hzCmdSymId    = cmSymTblRegisterStaticSymbol(ctx->stH,"hz");
  p->resetSymId    = cmSymTblRegisterStaticSymbol(ctx->stH,"reset");
  
  for(i=0,j=0; i<chCnt; ++i)
  {
    double hz = cmMidiToHz(ccp->chArray[i].midi);
    cmDspSetDefaultDouble(ctx, &p->inst, kGainBaseCcId   + i,   0.0, ccp->chArray[i].gain);
    cmDspSetDefaultUInt(  ctx, &p->inst, p->midiBaseCcId + i,   0,   ccp->chArray[i].midi );
    cmDspSetDefaultDouble(ctx, &p->inst, p->hzBaseCcId   + i,   0.0, hz );
    cmDspSetDefaultUInt(  ctx, &p->inst, p->chBaseCcId   + i,   0,   ccp->chArray[i].ch );
    cmDspSetDefaultBool(  ctx, &p->inst, p->nsflBaseCcId+i, false, false );
    if( ccp->chArray[i].nsFl )
    {
      cmDspSetDefaultDouble(ctx,&p->inst, p->nshzBaseCcId+j, 0.0, hz);
      ++j;
    }
    
  }
  
  
  cmDspSetDefaultSymbol(ctx, &p->inst, kDoneCcId, cmInvalidId );
  cmDspSetDefaultSymbol(ctx, &p->inst, kSelCcId,  cmInvalidId );
  
  return &p->inst;
}

cmDspRC_t _cmDspChCfgFree(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspChCfg_t* p = (cmDspChCfg_t*)inst;
  cmChCfgFree(&p->ccp);
  return kOkDspRC;
}

cmDspRC_t _cmDspChCfgReset(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t      rc = kOkDspRC;
  rc = cmDspApplyAllDefaults(ctx,inst);
  return rc;  
}


cmDspRC_t _cmDspChCfgRecv(cmDspCtx_t* ctx, cmDspInst_t* inst, const cmDspEvt_t* evt )
{
  cmDspRC_t     rc;
  cmDspChCfg_t* p = (cmDspChCfg_t*)inst;
  
  if((rc = cmDspSetEvent(ctx,inst,evt)) == kOkDspRC )
  {
    if( evt->dstVarId == kSelCcId )
    {
      unsigned selId = cmDspSymbol(inst,kSelCcId);
      
      if( selId == p->resetSymId )
      {
        _cmDspChCfgReset(ctx,inst,evt);
      }
      else
        if( selId == p->hzCmdSymId )
      {
        unsigned i;
        // snd the  hz
        for(i=0; i<p->ccp->chCnt; ++i)
          cmDspSetDouble(ctx,inst,p->hzBaseCcId+i,cmDspDouble(inst,p->hzBaseCcId+i));
        
      }
      else
        if( selId == p->nsCmdSymId )
      {
        cmRptPrintf(ctx->rpt,"ChCfg:NS\n");
        
        unsigned i;
        // send the ns flags
        for(i=0; i<p->ccp->chCnt; ++i)
          cmDspSetBool(ctx,inst,p->nsflBaseCcId+i,p->ccp->chArray[i].nsFl);
        
        // snd the ns hz
        for(i=0; i<p->ccp->nsChCnt; ++i)
          cmDspSetDouble(ctx,inst,p->nshzBaseCcId+i,cmDspDouble(inst,p->nshzBaseCcId+i));
        
        cmDspSetSymbol(ctx,inst,kDoneCcId,p->nsCmdSymId);
        
      }
      else
        
      if( selId == p->printSymId )
      {
        cmRptPrintf(&ctx->cmCtx->rpt,"Channel Cfg Report\n");
        cmChCfgPrint(p->ccp, ctx->rpt );
      }
      else
      {
        if( selId == p->writeSymId )
        {
          unsigned i;
          
          cmRptPrintf(&ctx->cmCtx->rpt,"writing\n");
          
          // copy the gain values into the internal chCfg object ...
          for(i=0; i<p->ccp->chCnt; ++i)
            p->ccp->chArray[i].gain = cmDspDouble(inst,kGainBaseCcId+i);
          
          // ... and write the object
          cmChCfgWrite(p->ccp);
        }
      }
    }
  }
  
  return rc;
}

cmDspClass_t* cmChCfgClassCons( cmDspCtx_t* ctx )
{
  cmDspClassSetup(&_cmChCfgDC,ctx,"ChCfg",
  NULL,
  _cmDspChCfgAlloc,
  _cmDspChCfgFree,
  _cmDspChCfgReset,
  NULL,
  _cmDspChCfgRecv,
  NULL,NULL,
  "PP Channel Configuration Object.");
  
  return &_cmChCfgDC;
}