src/add-ons/kernel/drivers/audio/echo/generic/CMidiInQ.h

   1 // ****************************************************************************
   2 //
   3 //              CMidiInQ.h
   4 //
   5 //      This class manages MIDI input.
   6 //
   7 //              Use a simple fixed size queue for storing MIDI data.
   8 //
   9 //              Fill & drain pointers are maintained automatically whenever
  10 //              an Add or Get function succeeds.
  11 //
  12 //              Set editor tabs to 3 for your viewing pleasure.
  13 //
  14 // ----------------------------------------------------------------------------
  15 //
  16 // This file is part of Echo Digital Audio's generic driver library.
  17 // Copyright Echo Digital Audio Corporation (c) 1998 - 2005
  18 // All rights reserved
  19 // www.echoaudio.com
  20 //
  21 // This library is free software; you can redistribute it and/or
  22 // modify it under the terms of the GNU Lesser General Public
  23 // License as published by the Free Software Foundation; either
  24 // version 2.1 of the License, or (at your option) any later version.
  25 //
  26 // This library is distributed in the hope that it will be useful,
  27 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  28 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  29 // Lesser General Public License for more details.
  30 //
  31 // You should have received a copy of the GNU Lesser General Public
  32 // License along with this library; if not, write to the Free Software
  33 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  34 //
  35 // ****************************************************************************
  36
  37 //      Prevent problems with multiple includes
  38 #ifndef _MIDIQUEUEOBJECT_
  39 #define _MIDIQUEUEOBJECT_
  40
  41 #include "CMtcSync.h"
  42
  43 typedef struct tMIDI_DATA
  44 {
  45         DWORD           dwMidi;
  46         LONGLONG        llTimestamp;
  47 }
  48 MIDI_DATA;
  49
  50 typedef MIDI_DATA *PMIDI_DATA;
  51
  52 //
  53 // Default to one MIDI input client
  54 //
  55 #ifndef MAX_MIDI_IN_CLIENTS
  56 #define MAX_MIDI_IN_CLIENTS             1
  57 #endif
  58
  59 //
  60 // MIDI in queue size
  61 //
  62 // Total buffer size in bytes will be MIDI_IN_Q_SIZE * sizeof(MIDI_DATA)
  63 //
  64 // Buffer size must be a power of 2.  This is the default size; to change it,
  65 // add #define MIDI_IN_Q_SIZE to your OsSupport??.h file
  66 //
  67 #ifndef MIDI_IN_Q_SIZE
  68 #define MIDI_IN_Q_SIZE  128
  69 #endif
  70
  71 //
  72 //      Class used for simple MIDI byte queue
  73 //
  74 class CMidiInQ
  75 {
  76 public:
  77         //
  78         //      Construction/destruction
  79         //
  80         CMidiInQ();
  81         ~CMidiInQ();
  82
  83         //
  84         // Init
  85         //
  86         ECHOSTATUS Init(CEchoGals *pEG);
  87
  88         //
  89         //      Get the oldest byte from the circular buffer
  90         //
  91         ECHOSTATUS GetMidi
  92         (
  93                 ECHOGALS_MIDI_IN_CONTEXT        *pContext,
  94                 DWORD                                                   &dwMidiByte,
  95                 LONGLONG                                                        &llTimestamp
  96         );
  97
  98         //
  99         // Enable and disable MIDI input and MTC sync
 100         //
 101         ECHOSTATUS Arm(ECHOGALS_MIDI_IN_CONTEXT *pContext);
 102         ECHOSTATUS Disarm(ECHOGALS_MIDI_IN_CONTEXT *pContext);
 103         ECHOSTATUS ArmMtcSync();
 104         ECHOSTATUS DisarmMtcSync();
 105
 106         //
 107         // Get and set MTC base rate
 108         //
 109         ECHOSTATUS GetMtcBaseRate(DWORD *pdwBaseRate);
 110         ECHOSTATUS SetMtcBaseRate(DWORD dwBaseRate);
 111
 112         //
 113         // If MTC sync is turned on, process received MTC data
 114         // and update the sample rate
 115         //
 116         void ServiceMtcSync();
 117
 118         //
 119         // See if there has been any recent MIDI input activity
 120         //
 121         BOOL IsActive();
 122
 123         //
 124         //      Reset the in/out ptrs
 125         //
 126         void Reset(ECHOGALS_MIDI_IN_CONTEXT *pContext);
 127
 128         //
 129         // Service a MIDI input interrupt
 130         //
 131         ECHOSTATUS ServiceIrq();
 132
 133
 134 protected:
 135
 136         //
 137         // Add a MIDI byte to the circular buffer
 138         //
 139         inline ECHOSTATUS AddMidi
 140         (
 141                 DWORD           dwMidiByte,
 142                 LONGLONG        llTimestamp
 143         );
 144
 145         //
 146         // Parse MIDI time code data
 147         //
 148         DWORD MtcProcessData( DWORD dwMidiData );
 149
 150         //
 151         // Cleanup
 152         //
 153         void Cleanup();
 154
 155         //
 156         //      Midi buffer management
 157         //
 158         PMIDI_DATA      m_pBuffer;
 159         DWORD                   m_dwFill;
 160         DWORD                   m_dwBufferSizeMask;
 161         DWORD                   m_dwNumClients;
 162
 163         //
 164         // Most recent MIDI input time - used for activity detector
 165         //
 166         ULONGLONG       m_ullLastActivityTime;
 167
 168         //
 169         // MIDI time code
 170         //
 171         WORD                    m_wMtcState;
 172         CMtcSync                *m_pMtcSync;
 173
 174         //
 175         // Other objects
 176         //
 177         CEchoGals               *m_pEG;
 178
 179 };              // class CMidiInQ
 180
 181 typedef CMidiInQ * PCMidiInQ;
 182
 183 #endif
 184
 185 // *** CMidiInQ.H ***