src/add-ons/kernel/drivers/audio/echo/generic/CEchoGalsMTC.cpp

   1 // ****************************************************************************
   2 //
   3 //              CEchoGalsMTC.cpp
   4 //
   5 //              CEchoGalsMTC is used to add MIDI time code sync to the base
   6 //              CEchoGals class.  CEchoGalsMTC derives from CEchoGals; CLayla and
   7 //              CLayla24 derive in turn from CEchoGalsMTC.
   8 //
   9 //              Set editor tabs to 3 for your viewing pleasure.
  10 //
  11 // ----------------------------------------------------------------------------
  12 //
  13 // This file is part of Echo Digital Audio's generic driver library.
  14 // Copyright Echo Digital Audio Corporation (c) 1998 - 2005
  15 // All rights reserved
  16 // www.echoaudio.com
  17 //
  18 // This library is free software; you can redistribute it and/or
  19 // modify it under the terms of the GNU Lesser General Public
  20 // License as published by the Free Software Foundation; either
  21 // version 2.1 of the License, or (at your option) any later version.
  22 //
  23 // This library is distributed in the hope that it will be useful,
  24 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  25 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  26 // Lesser General Public License for more details.
  27 //
  28 // You should have received a copy of the GNU Lesser General Public
  29 // License along with this library; if not, write to the Free Software
  30 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  31 //
  32 // ****************************************************************************
  33
  34 #include "CEchoGalsMTC.h"
  35
  36
  37 //****************************************************************************
  38 //
  39 // Constructor and destructor
  40 //
  41 //****************************************************************************
  42
  43 CEchoGalsMTC::CEchoGalsMTC( PCOsSupport pOsSupport )
  44                   : CEchoGals( pOsSupport )
  45 {
  46         ECHO_DEBUGPRINTF( ( "CEchoGalsMTC::CEchoGalsMTC() is born!\n" ) );
  47
  48         m_wInputClock = ECHO_CLOCK_INTERNAL;
  49
  50 }       // CEchoGalsMTC::CEchoGalsMTC()
  51
  52
  53 CEchoGalsMTC::~CEchoGalsMTC()
  54 {
  55         ECHO_DEBUGPRINTF( ( "CEchoGalsMTC::~CEchoGalsMTC() is toast!\n" ) );
  56 }       // CEchoGalsMTC::~CEchoGalsMTC()
  57
  58
  59
  60
  61 //****************************************************************************
  62 //
  63 // Input clock
  64 //
  65 //****************************************************************************
  66
  67 //============================================================================
  68 //
  69 // Set the input clock
  70 //
  71 // This needs to intercept the input clock value here since MTC sync is
  72 // actually implemented in software
  73 //
  74 //============================================================================
  75
  76 ECHOSTATUS CEchoGalsMTC::SetInputClock(WORD wClock)
  77 {
  78         ECHOSTATUS Status;
  79
  80         Status = ECHOSTATUS_OK;
  81
  82         //
  83         // Check for MTC clock
  84         //
  85         if (ECHO_CLOCK_MTC == wClock)
  86         {
  87                 if (ECHO_CLOCK_MTC != m_wInputClock)
  88                 {
  89                         //
  90                         // Tell the MIDI input object to enable MIDI time code sync
  91                         //
  92                         Status = m_MidiIn.ArmMtcSync();
  93
  94                         if (ECHOSTATUS_OK == Status)
  95                         {
  96                                 //
  97                                 // Store the current clock as MTC...
  98                                 //
  99                                 m_wInputClock = ECHO_CLOCK_MTC;
 100
 101                                 //
 102                                 // but set the real clock to internal.
 103                                 //
 104                                 Status = CEchoGals::SetInputClock( ECHO_CLOCK_INTERNAL );
 105                         }
 106
 107                 }
 108         }
 109         else
 110         {
 111                 //
 112                 // Pass the clock setting to the base class
 113                 //
 114                 Status = CEchoGals::SetInputClock( wClock );
 115                 if (ECHOSTATUS_OK == Status)
 116                 {
 117                         WORD wOldClock;
 118                         DWORD dwRate;
 119
 120                         //
 121                         // Get the base rate for MTC sync
 122                         //
 123                         m_MidiIn.GetMtcBaseRate( &dwRate );
 124
 125                         //
 126                         // Make sure MTC sync is off
 127                         //
 128                         m_MidiIn.DisarmMtcSync();
 129
 130                         //
 131                         // Store the new clock
 132                         //
 133                         wOldClock = m_wInputClock;
 134                         m_wInputClock = wClock;
 135
 136                         //
 137                         // If the previous clock was MTC, re-set the sample rate
 138                         //
 139                         if (ECHO_CLOCK_MTC == wOldClock)
 140                                 SetAudioSampleRate( dwRate );
 141                 }
 142         }
 143
 144         return Status;
 145
 146 }       // SetInputClock
 147
 148
 149 //============================================================================
 150 //
 151 // Get the input clock
 152 //
 153 //============================================================================
 154
 155 ECHOSTATUS CEchoGalsMTC::GetInputClock(WORD &wClock)
 156 {
 157         wClock = m_wInputClock;
 158
 159         return ECHOSTATUS_OK;
 160 }
 161
 162
 163 //****************************************************************************
 164 //
 165 // Sample rate
 166 //
 167 //****************************************************************************
 168
 169 //============================================================================
 170 //
 171 // Set the sample rate
 172 //
 173 // Again, the rate needs to be intercepted here.
 174 //
 175 //============================================================================
 176
 177 ECHOSTATUS CEchoGalsMTC::SetAudioSampleRate( DWORD dwSampleRate )
 178 {
 179         ECHOSTATUS Status;
 180
 181         //
 182         // Syncing to MTC?
 183         //
 184         if (ECHO_CLOCK_MTC == m_wInputClock)
 185         {
 186                 //
 187                 // Test the rate
 188                 //
 189                 Status = QueryAudioSampleRate( dwSampleRate );
 190
 191                 //
 192                 // Set the base rate if it's OK
 193                 //
 194                 if (ECHOSTATUS_OK == Status)
 195                 {
 196                         m_MidiIn.SetMtcBaseRate( dwSampleRate );
 197                 }
 198         }
 199         else
 200         {
 201                 //
 202                 // Call the base class
 203                 //
 204                 Status = CEchoGals::SetAudioSampleRate( dwSampleRate );
 205         }
 206
 207         return Status;
 208
 209 }       // SetAudioSampleRate
 210
 211
 212 //============================================================================
 213 //
 214 // Get the sample rate
 215 //
 216 //============================================================================
 217
 218 ECHOSTATUS CEchoGalsMTC::GetAudioSampleRate( PDWORD pdwSampleRate )
 219 {
 220         ECHOSTATUS Status;
 221
 222         if (NULL == pdwSampleRate)
 223                 return ECHOSTATUS_INVALID_PARAM;
 224
 225         //
 226         // Syncing to MTC?
 227         //
 228         if (ECHO_CLOCK_MTC == m_wInputClock)
 229         {
 230                 //
 231                 // Get the MTC base rate
 232                 //
 233                 Status = m_MidiIn.GetMtcBaseRate( pdwSampleRate );
 234         }
 235         else
 236         {
 237                 //
 238                 // Call the base class
 239                 //
 240                 Status = CEchoGals::GetAudioSampleRate( pdwSampleRate );
 241         }
 242
 243         return Status;
 244
 245 }       // GetAudioSampleRate
 246
 247
 248
 249
 250 //****************************************************************************
 251 //
 252 // Call this periodically to change the sample rate based on received MTC
 253 // data
 254 //
 255 //****************************************************************************
 256
 257 void CEchoGalsMTC::ServiceMtcSync()
 258 {
 259         m_MidiIn.ServiceMtcSync();
 260 }
 261
 262
 263 // *** CEchoGalsMTC.cpp ***