jdkmidi class library documentation
Copyright © 2004 J.D. Koftinoff Software, Ltd.
Released under the GNU General Public License (GPL)

---

src/jdkmidi_fileread.cpp

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/*
 *  libjdkmidi-2004 C++ Class Library for MIDI
 *
 *  Copyright (C) 2004  J.D. Koftinoff Software, Ltd.
 *  www.jdkoftinoff.com
 *  jeffk@jdkoftinoff.com
 *
 *  *** RELEASED UNDER THE GNU GENERAL PUBLIC LICENSE (GPL) April 27, 2004 ***
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
/*
**  Copyright 1986 to 1998 By J.D. Koftinoff Software, Ltd.
**
**  All rights reserved.
**
**  No one may duplicate this source code in any form for any reason
**  without the written permission given by J.D. Koftinoff Software, Ltd.
**
*/

#include "jdkmidi/world.h"

#include "jdkmidi/fileread.h"

// TO DO: decide which way is right for this flag and fix it - The standard midi file format specs are (were?) unclear

#define MIDIFRD_ALLOW_STATUS_ACROSS_META_EVENT  0

namespace jdkmidi
{
  
  
  void  MIDIFileEvents::UpdateTime( MIDIClockTime delta_time )  
  {
    
  } 
  
  void  MIDIFileEvents::ChanMessage( const MIDITimedMessage &msg )  
  {
    
    switch( msg.GetStatus()&0xf0 )
    {
    case NOTE_OFF:
      mf_note_off( msg );
      break;
    case NOTE_ON:
      if( msg.GetVelocity()==0 )
      {
        mf_note_off( msg );
      }
      else
      {
        mf_note_on( msg );
      }
      break;
    case POLY_PRESSURE:
      mf_poly_after( msg );
      break;
    case CONTROL_CHANGE:
      if( msg.GetByte2()>C_ALL_NOTES_OFF )
      {
        mf_system_mode( msg );
      }
      else
      {
        mf_control( msg );
      }
      break;
    case PROGRAM_CHANGE:
      mf_program( msg );
      break;
    case CHANNEL_PRESSURE:
      mf_chan_after( msg );
      break;
    case PITCH_BEND:
      mf_bender( msg );
      break;
      
    } 
  } 
  
  void  MIDIFileEvents::MetaEvent(MIDIClockTime time, int type, int leng, unsigned char *m )  
  {
    
    switch  ( type ) {
    case MF_SEQUENCE_NUMBER:
      mf_seqnum( time, To16Bit( m[0], m[1] ) );
      break;
    case MF_TEXT_EVENT:
    case MF_COPYRIGHT:
    case MF_TRACK_NAME:
    case MF_INSTRUMENT_NAME:
    case MF_LYRIC:
    case MF_MARKER:
    case MF_CUE_POINT:
    case MF_GENERIC_TEXT_8:
    case MF_GENERIC_TEXT_9:
    case MF_GENERIC_TEXT_A:
    case MF_GENERIC_TEXT_B:
    case MF_GENERIC_TEXT_C:
    case MF_GENERIC_TEXT_D:
    case MF_GENERIC_TEXT_E:
    case MF_GENERIC_TEXT_F:
      
      // These are all text events
      
      m[leng]=0;      // make sure string ends in NULL
      mf_text(time,type, leng, m );
      break;
    case MF_OUTPUT_CABLE:
      // TO DO:
      break;
    case MF_TRACK_LOOP:
      // TO DO:
      break;
    case MF_END_OF_TRACK:      // End of Track
      mf_eot( time );
      break;
      
    case MF_TEMPO:      // Set Tempo
      mf_tempo( time, To32Bit(0,m[0],m[1],m[2]) );
      break;
      
    case MF_SMPTE:
      mf_smpte( time, m[0],m[1],m[2],m[3],m[4]);
      break;
      
    case MF_TIMESIG:
      mf_timesig( time, m[0],m[1],m[2],m[3]);
      break;
      
    case MF_KEYSIG:
    {
      char c=m[0];
      mf_keysig(time, c,m[1]);
    }
    break;
    
    case MF_SEQUENCER_SPECIFIC:
      mf_sqspecific(time, leng,m);
      break;
      
    default:
      mf_metamisc(time, type,leng,m);
      break;
    }
  } 
  
  void    MIDIFileEvents::mf_starttrack( int trk )  
  {
    
  } 
  
  void    MIDIFileEvents::mf_endtrack( int trk )  
  {
    
  } 
  
  void    MIDIFileEvents::mf_eot( MIDIClockTime time )  
  {
    
  } 
  
  void    MIDIFileEvents::mf_error( char *s ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_header(
    int a, 
    int b, 
    int c ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_arbitrary(
    MIDIClockTime time,
    int a, 
    unsigned char *s )  
  {
    
  } 
  
  void    MIDIFileEvents::mf_metamisc(  
    MIDIClockTime time,
    int a, 
    int b, 
    unsigned char *s )  
  {
    
  } 
  
  void    MIDIFileEvents::mf_seqnum(    
    MIDIClockTime time,
    int a)  
  {
    
  } 
  
  void    MIDIFileEvents::mf_smpte( 
    MIDIClockTime time,
    int a, 
    int b, 
    int c, 
    int d, 
    int e)  
  {
    
  } 
  
  void    MIDIFileEvents::mf_timesig(   
    MIDIClockTime time,
    int a, 
    int b, 
    int c, 
    int d ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_tempo( 
    MIDIClockTime time,
    unsigned long a)  
  {
    
  } 
  
  void    MIDIFileEvents::mf_keysig( 
    MIDIClockTime time,
    int a,
    int b)  
  {
    
  } 
  
  void    MIDIFileEvents::mf_sqspecific( 
    MIDIClockTime time,
    int a,
    unsigned char *s )  
  {
    
  } 
  
  void    MIDIFileEvents::mf_text(
    MIDIClockTime time,
    int a, 
    int b, 
    unsigned char *s )  
  {
    
  } 
  
  void    MIDIFileEvents::mf_system_mode(const MIDITimedMessage &msg  ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_note_on(const MIDITimedMessage &msg  ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_note_off(const MIDITimedMessage &msg   ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_poly_after(const MIDITimedMessage &msg   ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_bender(const MIDITimedMessage &msg   ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_program(const MIDITimedMessage &msg  ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_chan_after(const MIDITimedMessage &msg   ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_control(const MIDITimedMessage &msg  ) 
  {
    
  } 
  
  void    MIDIFileEvents::mf_sysex(
    MIDIClockTime time,
    const MIDISystemExclusive &ex 
    ) 
  {
    
  } 
  
  
  
  
  
  MIDIFileRead::MIDIFileRead( 
    MIDIFileReadStream *input_stream_,
    MIDIFileEvents *event_handler_,
    unsigned long max_msg_len_ 
    ) 
    : 
    input_stream( input_stream_ ),
    event_handler( event_handler_ )
  {
    no_merge=0;
    cur_time=0;
    skip_init=1;
    to_be_read=0;
    msg_index=0;
    cur_track=0;
    abort_parse=0;
    max_msg_len=max_msg_len_;
    the_msg = new unsigned char[max_msg_len];
  } 
  
  MIDIFileRead::~MIDIFileRead() 
  {
    delete [] the_msg;
  } 
  
  void MIDIFileRead::mf_error( char *e )  
  {
    event_handler->mf_error(e);
    abort_parse=true;   
  } 
  
  bool MIDIFileRead::Parse()  
  {
    int n;
    
    n = ReadHeader();
    if( n <=0 )
    {
      mf_error( "No Tracks" );
      return false;
    }
    for( cur_track=0; cur_track<n; cur_track++ )
    {
      ReadTrack();
      if( abort_parse )
      {
        return false;
      }
    }
    return true;
  } 
  
  int MIDIFileRead::ReadMT( unsigned long type, int skip )  
  {
    unsigned long read=0;
    int c;       
    
    read=OSTYPE( EGetC(), EGetC(), EGetC(), EGetC() );
    if( type!=read )
    {
      if( skip )
      {
        do
        {
          read<<=8;
          c=EGetC();
          read|=c;
          if( read==type )
            return true;
          if( abort_parse )
            return false;
          
        } while( c!=-1 );
      }
      mf_error( "Error looking for chunk type" );
      return false;
    }
    else
    {
      return true;
    }
    
  } 
  
  int MIDIFileRead::ReadHeader()  
  {
    int   the_format;
    int  ntrks;
    int   division;
    
    if( ReadMT( _MThd, skip_init )==0xffff )
      return 0;
    
    if( abort_parse )
      return 0;
    
    to_be_read = Read32Bit();
    the_format=Read16Bit();
    ntrks=Read16Bit();
    division=Read16Bit();
    
    if( abort_parse )
      return 0;
    
    
    header_format=the_format;
    header_ntrks=ntrks;
    header_division=division;
    
    event_handler->mf_header( the_format, ntrks, division );
    
    
    // printf( "\nto be read = %d\n", to_be_read );
    
    while( to_be_read > 0 )
      EGetC();
    
    return ntrks;
  } 
  
//
// read a track chunk
//
  
  void MIDIFileRead::ReadTrack()  
  {
    //
    // This array is indexed by the high half of a status byte.  Its
    // value is either the number of bytes needed (1 or 2) for a channel
    // message, or 0 (meaning it's not  a channel message).
    //
    
    static char chantype[] = 
      {
        0, 0, 0, 0, 0, 0, 0, 0,         // 0x00 through 0x70
        2, 2, 2, 2, 1, 1, 2, 0          // 0x80 through 0xf0
      };
    
    unsigned long lookfor, lng;
    int c, c1, type;
    int sysexcontinue=0; // 1 if last message was unfinished sysex
    int running=0;       // 1 when running status used
    int status=0;                // (possible running) status byte
    int needed;
    
    
    if( ReadMT( _MTrk, 0) == 0xffff )
      return;
    
    to_be_read=Read32Bit();
    cur_time=0;
    
    event_handler->mf_starttrack( cur_track );
    
    while( to_be_read > 0 && !abort_parse )
    {
      unsigned long deltat=ReadVariableNum();
      
      event_handler->UpdateTime( deltat );
      
      cur_time += deltat;
      
      c=EGetC();
      
      if( c==-1 )
        break;
      
      if( sysexcontinue && c!=0xf7 )
        mf_error( "Error after expected continuation of SysEx" );
      
      if( (c&0x80)==0 )
      {
        if( status==0 )
          mf_error( "Unexpected Running Status" );
        running=1;
        needed = chantype[ (status>>4) & 0xf ];
      }
      else
      {
        // TO DO: is running status to be cleared or not when meta event happens?
        
#if MIDIFRD_ALLOW_STATUS_ACROSS_META_EVENT
        if(  c!=0xff )
        {
          status=c;
          running=0;
          needed=0;
        }
        
#else
        status=c;
        running=0;
        needed = chantype[ (status>>4) & 0xf ]; 
#endif
        
      }
      
      
      
      if( needed )            // ie. is it a channel message?
      {
        if( running )
          c1=c;
        else
          c1=EGetC();
        FormChanMessage( (unsigned char)status, (unsigned char)c1, (unsigned char)((needed>1) ? EGetC() : 0 ));
        continue;
      }
      
      
      switch( c )
      {
      case 0xff:              // meta-event
        type=EGetC();
        lng = ReadVariableNum();
        
        lookfor = to_be_read - lng;
        
        MsgInit();
        while( to_be_read > lookfor)
        {
          MsgAdd( EGetC() );
        }
        
        event_handler->MetaEvent( cur_time, type, msg_index, the_msg );
        break;
        
      case 0xf0:              // start of sys-ex
        lng = ReadVariableNum();
        lookfor = to_be_read - lng;
        
        MsgInit();
        MsgAdd(0xf0);
        
        while( to_be_read>lookfor )
          MsgAdd( c=EGetC() );
        
        if( c==0xf7 || no_merge==0 )
        {
          // make a sysex object out of the raw sysex data
          // the buffer is not to be deleted upon destruction of ex
          
          MIDISystemExclusive ex(
            the_msg,
            msg_index,
            msg_index,
            false
            );
          
          // give the sysex object to our event handler
          
          event_handler->mf_sysex( cur_time, ex );
        }
        else
          sysexcontinue=1; // merge into next msg
        break;
      case 0xf7:              // sysex continuation or 
        // arbitary stuff
        lng=ReadVariableNum();
        lookfor = to_be_read - lng;
        
        if( ! sysexcontinue )
          MsgInit();
        
        while( to_be_read > lookfor )
          MsgAdd(c=EGetC());
        
        if( !sysexcontinue )
        {
          event_handler->mf_arbitrary( cur_time, msg_index, the_msg );
        }
        else if( c== 0xf7 )
        {
          // make a sysex object out of the raw sysex data
          // the buffer is not to be deleted upon destruction of ex
          
          MIDISystemExclusive ex(
            the_msg,
            msg_index,
            msg_index,
            false
            );
          event_handler->mf_sysex( cur_time, ex );
          sysexcontinue=0;
        }
        break;
      default:
        BadByte(c);
        break;
      }
    }
    event_handler->mf_endtrack( cur_track );
    return;
  } 
  
  unsigned long MIDIFileRead::ReadVariableNum() 
  {
    unsigned long value;
    int c;
    
    c=EGetC();
    if( c==-1 )
    {
      return 0;
    }
    value = c;
    
    if( c & 0x80 )
    {
      value &= 0x7f;
      do
      {
        c=EGetC();
        value =  (value<<7) + (c&0x7f);
      } while( c&0x80 );
    }
    return value;
  } 
  
  unsigned long MIDIFileRead::Read32Bit() 
  {
    int c1, c2, c3, c4;
    
    c1=EGetC();
    c2=EGetC();
    c3=EGetC();
    c4=EGetC();
    
    return To32Bit( (unsigned char)c1, (unsigned char)c2, (unsigned char)c3, (unsigned char)c4 );
  } 
  
  int MIDIFileRead::Read16Bit() 
  {
    int c1, c2;
    
    c1=EGetC();
    c2=EGetC();
    
    return To16Bit( (unsigned char)c1, (unsigned char)c2 );
  } 
  
  int MIDIFileRead::EGetC() 
  {
    int c;
    
    c = input_stream->ReadChar();
    
    
    if( c<0 )
    {
      mf_error( "Unexpected Stream Error" );
      abort_parse=true;
      return -1;
    }
    
    --to_be_read;
    
    return (int)c;
  } 
  
  void MIDIFileRead::MsgAdd( int a )  
  {
    if( msg_index<max_msg_len )
      the_msg[ msg_index++ ] = (unsigned char)a;
  } 
  
  void MIDIFileRead::MsgInit()  
  {
    msg_index=0;
  } 
  
  void MIDIFileRead::BadByte( int c ) 
  {
    mf_error( "Unexpected Byte" );
    abort_parse=true;
  } 
  
  void MIDIFileRead::FormChanMessage( unsigned char st, unsigned char b1, unsigned char b2 )  
  {
    MIDITimedMessage m;
    
    m.SetStatus( st );
    m.SetByte1( b1 );
    m.SetByte2( b2 );
    m.SetTime( cur_time );
    
    if( st>=0x80 && st<0xf0 )
    {
      event_handler->ChanMessage(m);
    }
    
  } 
  
  
}