player_smf.c

一个很好的c++ midi解码算法,不依赖于任何平台.

/*
 *  player_smf.cc
 *  Copyright (C) 1998-2000 SAKAI Katsuya
 *
 *  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
 */

#include <stdio.h>// #include <iostream.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <string.h>
#include <stdio.h>

#include "config.h"
#include "sequencer.h"
#include "smf.h"
#include "player.h"
#include "queue.h"

#include "extern.h"
#include "defines.h"

SMF_Player::SMF_Player()
{
  Track=NULL;
}

SMF_Player::~SMF_Player()
{
  clear();
}

void SMF_Player::init()
{
  int n;
  Event *NextEvent;
  for(n=0;n<Header.NumOfTrack;n++)
    {
      if(strncmp(Track[n].Type, "MTrk", 4)==0)
	{
	  Track[n].init();
	  NextEvent = new Event;
	  NextEvent->Track = n;
	  NextEvent->Time = Track[n].tick();
	  Queue.store(NextEvent);
	}
    }
  
  aSequencer->set_tempo (60*1000000/120); // Default Tempo 120bpm
}

//遍琳メインル〖チン
void SMF_Player::play()
{
  Event *Next;
  aSequencer->startTimer();
  while((Next=Queue.retrieve())!=NULL && stop==FALSE && next==FALSE)
    {
      aSequencer->waitTime (Next->Time);
      if(Track[Next->Track].playaEvent()<0)
	{
	  delete Next;
	}
      else
	{
	  Next->Time = Track[Next->Track].tick();
	  Queue.store(Next);
	}
    }
  if(stop==TRUE || next==TRUE)
    {
      aSequencer->reset();
      aSequencer->seqbuf_clear();
      AllNoteOff();
      while((Next=Queue.retrieve())!=NULL) delete Next;
      next=FALSE;
    }
  aSequencer->stopTimer();
  if(stop==TRUE)
    {
#ifdef SHOW_INFO
      cout << "stop." << endl;
#endif
      aSequencer->close();
      usleep (1000);
      exit(0);
    }
}

void SMF_Player::AllNoteOff()
{
  int devnum, m;
  devnum = aSequencer->NumOfDevice();
  
  for(m=0;m<devnum;m++)
    aSequencer->AllNoteOff(m);
}

void SMF_Player::clear()
{
  if(Track!=NULL)
    {
      delete [] Track;
      Track=NULL;
    }
}

/*
  error:
  -1: fileオ〖プンエラ〖
  -2: unknown format
  -3: file broken  
  -4: memory allocation error
*/

int SMF_Player::load(char *filename)
{
  int songfd;
  int n;
  
  clear();
  if (filename==NULL)
    songfd = fileno(stdin);
  else
    songfd = open(filename, O_RDONLY);
  
  if(songfd<0)
    {
      return -1;
    }
  
  // ヘッダの矢机误チェック
  read(songfd, Header.Type, 4);
  if(strncmp(Header.Type, "MThd", 4)!=0)
    {
      lseek(songfd, 128L, SEEK_SET);  // Mac binary 滦忽
      read(songfd, Header.Type, 4);
      if(strncmp(Header.Type, "MThd", 4)!=0)
	{
	  if (filename==NULL)
	    close(songfd);
	  return -2;
	}
    }
  
  // ヘッダデ〖タ粕み哈み
  u_char buffer[8];
  read(songfd, buffer, 4);
  Header.Length =
    (buffer[0]<<24) + (buffer[1]<<16) + (buffer[2]<<8) + buffer[3];
#ifdef SHOW_HEADER
  cout << "header length:" << Header.Length << endl;
#endif
  if(Header.Length!=6)
    {
      if (filename==NULL)
	close (songfd);
      return -2;
    }
  read(songfd, buffer, 2);
  Header.Format = (buffer[0]<<8) + buffer[1];
  if(Header.Format > 1)
    {
      if (filename==NULL)
	close (songfd);
      return -2;
    }
  read(songfd, buffer, 2);
  Header.NumOfTrack = (buffer[0]<<8) + buffer[1];
  
  read(songfd, buffer, 2);
  aSequencer->set_timebase ((buffer[0]<<8) + buffer[1]);
  
#ifdef SHOW_HEADER
  cout << endl
       << "Format  :" << (int)Header.Format << endl
       << "Track   :" << Header.NumOfTrack << endl
       << "Timebase:" << aSequencer->show_timebase () << endl;
#endif
  
  Track = new SMF_Track [Header.NumOfTrack];
  if(!Track)
    {
      if (filename==NULL)
	close (songfd);
      return -4;
    }
  
  // トラックデ〖タの粕み哈み
  for(n=0;n<Header.NumOfTrack;n++)
    {
      Track[n].Number = n;
      if (read(songfd, Track[n].Type, 4)!=4)
	{
	  Header.NumOfTrack=n-1;
	  break;
	}
      if (strncmp (Track[n].Type, "MTrk", 4))
	{
	  Header.NumOfTrack=n-1;
	  break;
	}

      read(songfd, buffer, 4);
      Track[n].Length =
	(buffer[0]<<24) + (buffer[1]<<16) + (buffer[2]<<8) + buffer[3];
      
#ifdef SHOW_HEADER
      cout << endl;
      for(int i=0;i<4;i++) cout << Track[n].Type[i];
      cout << endl << "Track :" << Track[n].Number << endl
	   << "DataLength:" << Track[n].Length << endl;
#endif
      
      Track[n].Data = new u_char [ Track[n].Length ];
      if(!(Track[n].Data))
	{
	  if (filename==NULL)
	    close (songfd);
	  return -4;
	}
      if(read(songfd, Track[n].Data, Track[n].Length)<(long)Track[n].Length)
	{
	  if (filename==NULL)
	    close (songfd);
	  return -3;
	}
    }

#ifdef SHOW_HEADER
  cout << endl
       << "valid track:" << Header.NumOfTrack << endl;
#endif

  if (filename==NULL)
    close (songfd);
  return 0;
}