seq_oss_sio.cc.1

一个很好的c++ midi解码算法,不依赖于任何平台.

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

#include "defines.h"
#include "config.h"
#include "seq_oss_sio.h"
#include "extern.h"

#ifndef NO_OSS
#include SOUNDCARD_HEADER
#endif


int Seq_OSS_Serial::open(char *seqdev, int buflen)
{
  if(flagOpen == TRUE) return -1;

  // device open
  checkMidiDevice();
  char middevname[20] = MIDIDEVICE;
  int num;
  for (num=0;num<numberOfDevice-1;num++)
	{
	  if((midifd[num] = ::open(middevname, O_WRONLY | O_NDELAY))<0)
		{
		  cerr << "cannot open device ";
		  perror(middevname);
		  return -2;
		}
	}

  if((midifd[num] = ::open(seqdev, O_RDWR | O_NDELAY))<0)
	{
	  perror("cannot open device");
	  return -2;
	}
  struct termios tio;
  seqfd = midifd[num];
  if (tcgetattr (seqfd, &tio) < 0)
	{
	  return -1;
	}
  tio_orig = tio;
  tio.c_iflag = 0;
  tio.c_oflag = 0;
  tio.c_cflag = CS8 | CREAD | CLOCAL;
  tio.c_lflag = 0;
  cfsetispeed(&tio, B38400);
  cfsetospeed(&tio, B38400);
  if (tcsetattr (seqfd, TCSANOW, &tio) < 0)
	{
	  perror(" ");
	  return -3;
	}

  // buffer
  _buf = new u_char *[numberOfDevice];
  for (num=0;num<numberOfDevice;num++)
	_buf[num] = new u_char [buflen];
  _seqbuflen = buflen;
  _bufptr = new int [numberOfDevice];
  if(!_buf || !_bufptr)
	{
	  cerr << "allocation error" << endl;
	  return -3;
	}
  for (num=0;num<numberOfDevice;num++)
	{
	  _bufptr[num] = 0;
	}
  flagOpen = TRUE;

  u_char port=0;
  for (num=0;num<16;num++)
	{
	  if (port2dev[num]==numberOfDevice-1)
		{
		  SIOPORT[num]=port;
		  port++;
		}
	}
  return 0;
}

int Seq_OSS_Serial::close(){
  if(flagOpen != TRUE) return -1;
  stopTimer();
  flagOpen = FALSE;

  if (tcsetattr (seqfd, TCSANOW, &tio_orig) < 0)
    perror(" ");
  for (int num=0;num<numberOfDevice;num++)
	{
	  ::close (midifd[num]);
	}
  delete [] _buf;
  delete [] _bufptr;

  return 0;
}


int Seq_OSS_Serial::checkMidiDevice()
{
#ifndef NO_OSS
  int nrmidis, fd;
  static flag=0;
  if(flag==0)
	{
	  if ((fd = ::open(SEQUENCER, O_RDWR | O_NDELAY))<0)
		{
		  cerr << "can't open " << SEQUENCER << endl;
		  return -1;
		}
	  
	  if (ioctl(fd, SNDCTL_SEQ_NRMIDIS, &nrmidis) == -1)
		{
		  cerr << "can't get info about midi ports\n";
		  return -1;
		}
	  ::close (fd);
# ifdef SHOW_INFO
	  cout << "detect " << nrmidis << " midis." << endl;
# endif
	  numberOfDevice = 2;
	  flag=1;
	}
#endif

  return numberOfDevice;
}

void Seq_OSS_Serial::reset()
{
  seqbuf_dump();
  for (int num=0;num<numberOfDevice;num++)
	_bufptr[num] = 0;
}

void Seq_OSS_Serial::sync()
{
  seqbuf_dump();
}

int Seq_OSS_Serial::getCtrlRate()
{
  return 1000000;
}

void Seq_OSS_Serial::startTimer()
{
#ifdef RUNNING_ST
  for(int n=0;n<16;n++) clearStatus(n);
#endif
  LastOutputPort = 0;
  gettimeofday(&starttime, NULL);
}

void Seq_OSS_Serial::stopTimer()
{
  LastOutputPort = 0;
  seqbuf_dump();
}

void Seq_OSS_Serial::waitTime(u_long tick)
{
  static long waittime;
  seqbuf_dump();
  gettimeofday (&now, NULL);
  waittime = (long)tick - (now.tv_usec-starttime.tv_usec)
	- (now.tv_sec-starttime.tv_sec)*1000000;
  if(waittime>999)
	usleep (waittime);
}

void Seq_OSS_Serial::MidiOut(u_char port, char ch)
{
  u_char dev;
  dev = port2dev[port];
  if (dev==numberOfDevice-1) // $B%7%j%"%k%G%P%$%9$X$N=PNO$@$C$?$i(B
	{
	  if (port!=LastOutputPort)
		{
		  changePort (dev, SIOPORT[port]);
		  LastOutputPort = port;
		}
	}
  serial_midiout (dev, ch);
}

void Seq_OSS_Serial::midiEvent1(u_char port, u_char ev, u_char para1)
{
  u_char dev;
  dev = port2dev[port];
  if (dev==numberOfDevice-1)
	{
	  if (port!=LastOutputPort)
		{
		  changePort (dev, SIOPORT[port]);
		  LastOutputPort = port;
		}
	}

#ifdef RUNNING_ST
  if(LastStatus[dev]!=ev)
	{
#endif
	  serial_midiout (dev, ev);
#ifdef RUNNING_ST
	  LastStatus[dev]=ev;
	}
#endif
  serial_midiout (dev, para1);
}

void Seq_OSS_Serial::midiEvent2(u_char port, u_char ev, u_char para1, u_char para2)
{
  u_char dev;
  dev = port2dev[port];
  if (dev==numberOfDevice-1)
	{
	  if (port!=LastOutputPort)
		{
		  changePort (dev, SIOPORT[port]);
		  LastOutputPort = port;
		}
	}

#ifdef RUNNING_ST
  if(LastStatus[dev]!=ev)
	{
#endif
	  serial_midiout (dev, ev);
#ifdef RUNNING_ST
	  LastStatus[dev]=ev;
	}
#endif
  serial_midiout (dev, para1);
  serial_midiout (dev, para2);
}

#ifdef RUNNING_ST
void Seq_OSS_Serial::clearStatus(u_char port)
{
  LastStatus[port2dev[port]]=0;
}
#endif

void Seq_OSS_Serial::changePort(u_char dev, u_char port)
{
  if (dev&0x80) return;
  serial_midiout (dev, 0xF5);
  serial_midiout (dev, port+1);
#ifdef SHOW_PORTCHANGE
  cout << "change port:" << port+1 << endl;
#endif
#ifdef RUNNING_ST
  LastStatus[dev]=0;
#endif
}

int Seq_OSS_Serial::NumOfDevice()
{
  return numberOfDevice;
}

void Seq_OSS_Serial::AllNoteOff(u_char dev)
{
  int n;
  changePort(dev, 0);
  for(n=0;n<16;n++)
	{
	  serial_midiout (dev, 0xB0|n);
	  serial_midiout (dev, 64);
	  serial_midiout (dev, 0);
	  serial_midiout (dev, 0xB0|n);
	  serial_midiout (dev, 66);
	  serial_midiout (dev, 0);
	  serial_midiout (dev, 0xB0|n);
	  serial_midiout (dev, 123);
	  serial_midiout (dev, 0);
	  seqbuf_dump();
	}
}

void Seq_OSS_Serial::serial_midiout(u_char dev, u_char dat)
{
  if (dev&0x80) return;
  if (_bufptr[dev]>=_seqbuflen) seqbuf_dump();
  _buf[dev][_bufptr[dev]] = dat;
  _bufptr[dev]++;
}

void Seq_OSS_Serial::seqbuf_dump()
{
  for (int num=0;num<numberOfDevice;num++)
	{
	  if(_bufptr[num])
        if(write(midifd[num], _buf[num], _bufptr[num]) < 0)
          {
			perror("write error");
			exit(-1);
          }
	  _bufptr[num]=0;
	}
}