// ****************************************************************************
//
//              CMtcSync.h
//
//              Include file for interfacing with the CMtcSync class.
//              
//              This class manages syncing to MIDI time code.
//
//              Set editor tabs to 3 for your viewing pleasure.
//
// ----------------------------------------------------------------------------
//
// This file is part of Echo Digital Audio's generic driver library.
// Copyright Echo Digital Audio Corporation (c) 1998 - 2005
// All rights reserved
// www.echoaudio.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// ****************************************************************************

//      Prevent problems with multiple includes
#ifndef _MTCQUEUEOBJECT_
#define _MTCQUEUEOBJECT_

typedef struct tMTC_DATA
{
        DWORD   dwData;                 // DWORD here wastes memory, but is easier to debug...
        DWORD dwTimestamp;      // Timestamp in terms of the DSP sample count
} MTC_DATA;


//
//      CMtcSync
//
class CMtcSync
{
public:
        //
        //      Construction/destruction
        //
        CMtcSync( CEchoGals *pEG );
        ~CMtcSync();
        
        //
        // Methods used to store MTC data & timestamps
        //      
        void StoreTimestampHigh(DWORD dwData);
        void StoreTimestampLow(DWORD dwData);
        void StoreMtcData(DWORD dwData);
        
        //
        // Call this to process the MTC data and adjust the sample rate
        //
        void Sync();
        
        //
        //      Reset the state of things
        //
        void Reset();
        
        //
        //  Overload new & delete so memory for this object is allocated from non-paged memory.
        //
        PVOID operator new( size_t Size );
        VOID  operator delete( PVOID pVoid ); 

protected:

        enum    // Quarter-frame message types
        {
                MTC_QF_FRAME_LSN = 0,
                MTC_QF_FRAME_MSN,
                MTC_QF_SECOND_LSN,
                MTC_QF_SECOND_MSN,
                MTC_QF_MINUTE_LSN,
                MTC_QF_MINUTE_MSN,
                MTC_QF_HOUR_LSN,
                MTC_QF_HOUR_MSN,
                
                MTC_TOLERANCE           = 64,
                MTC_DAMPING                     = 98 * 0x1000 / 100,    // 95% in 12 bit fixed point
                
                MAX_DFRAME_SYNC_COUNT   = 4096,
                
                DAMPING_RATIO_LIMIT_LOW  = 4096 - 16,
                DAMPING_RATIO_LIMIT_HIGH = 4096 + 16
        };

        //
        //      Midi buffer management
        //
        MTC_DATA        m_Buffer[ ECHO_MTC_QUEUE_SZ ];
        DWORD                   m_dwFill;
        DWORD                   m_dwDrain;
        
        //
        // State information
        //
        DWORD                   m_dwBaseSampleRate;
        
        DWORD                   m_dwLastDframeTimestamp;        // Timestamp of last double frame 
                                                                                                                // in units of samples

        DWORD                   m_iSamplesPerDframe;
        DWORD                   m_dwFramesPerSec;
        
        DWORD                   m_dwLastDframe;                         // Last doubleframe number
        DWORD                   m_dwCurrentDframe;                      // Doubleframe number currently being assembled
                                                                                                                // from MTC data bytes
        
        DWORD                   m_iNumDframesSynced;                    // How many frames have elapsed since the
                                                                                                                // last sample rate adjustment
        
        INT32                   m_iNumSamplesSynced;                    // Sum of all actual timestamp deltas since
                                                                                                                // last sample rate adjustment
        DWORD                   m_dwNextQfType;
        
        DWORD                   m_dwTemp;
        
        //
        // Other stuff
        //
        CEchoGals       *m_pEG;
        
        friend class CMidiInQ;
        
};              // class CMtcSync

typedef CMtcSync * PCMtcSync;

#endif

// *** CMtcSync.H ***