midi_test2.py

midi_test2.py

#!/usr/bin/env python
# coding:utf-8
#
# midi_test.py
#
# Author:   Hiromasa Ihara (miettal)
# URL:      http://miettal.com
# License:  MIT License
# Created:  2014-06-05

import subprocess
import time

def midi_play(filename, callback) :
  with open(filename) as f :
    data = map(ord, f.read())
  
    header = data[:4+4+6]
    format_ = (header[6]<<8)+header[7]
    track_num = (header[8]<<8)+header[9]
    resolution = (header[12]<<8)+header[13]
    print """header:
    format:{}
    track_num:{}
    resolution:{}""".format(format_, track_num, resolution)
  
    i = 14
    tracks = []
    while i < len(data) :
      track_len = (data[i+4]<<24)+(data[i+5]<<16)+(data[i+6]<<8)+data[i+7]
      next_i = i+track_len+8
      tracks.append(data[i+8:next_i])
      i = next_i
  
    for track in tracks :
      i = 0
      while i < len(track) :
        #parse deltatime
        
        deltatime = 0
        while True :
          data = track[i]
          i += 1
          deltatime <<= 7
          deltatime += data&0x7f
          if ((data>>7) & 1) == 0: break
        print "deltatime:", 
        print deltatime
  
        try :
          duration_us = float(deltatime)/float(resolution)*float(tempo)
        except NameError :
          duration_us = 0.0
  
        if (track[i]&0xf0) == 0xf0 :
          # meta event
          if (track[i]&0x0f) == 0x0f :
            i += 1
            event_type = track[i]
            i += 1
            event_len = track[i]
            i += 1
            event_data = track[i:i+event_len]
            i += event_len
  
            if event_type == 0x08 :
              print "program name:",
              print ''.join(map(chr, event_data))
            elif event_type == 0x03 :
              print "seqence name:",
              print ''.join(map(chr, event_data))
            elif event_type == 0x02 :
              print "copyright:",
              print ''.join(map(chr, event_data))
            elif event_type == 0x01 :
              print "text:",
              print ''.join(map(chr, event_data))
            elif event_type == 0x2f :
              i += 1
              print "track end:"
            elif event_type == 0x51 :
              tempo = (event_data[0]<<16) + (event_data[1]<<8) + event_data[2]
              print "tempo:{}".format(tempo)
            elif event_type == 0x58 :
              nn = event_data[0]
              dd = event_data[1]
              bb = event_data[2]
              cc = event_data[3]
              print "hyoshi:{}/{}".format(nn, 2**dd)
            elif event_type == 0x59 :
              sf = event_data[0]
              mi = event_data[1]
              print "tyogo:", sf, mi
            elif event_type == 0x7f:
              origin_event = event_data[1:]
              print "origin event:", origin_event
            else :
              print "unknown meta event:",
              print hex(event_type),
              print event_data
  
          # SysEx event
          else :
            sysex_type = track[i]
            i += 1
            event_len = track[i]
            i += 1
            event_data = track[i:i+event_len]
            i += event_len
  
            if sysex_type == 0xF0 :
              print "F0 SysEx :",
              print event_data
            elif sysex_type == 0xF7 :
              print "F7 SysEx :",
              print event_data
            else :
              print "unknown SysEx event:",
              print map(hex, track[i:i+8])
  
        # midi event
        else :
          if (track[i]&0x80) == 0x80 :
            status_byte = track[i]
            i += 1
          else :
            pass
          n = status_byte&0x0f
  
          if (status_byte&0xf0) == 0x80 :
            kk = track[i]
            i += 1
            vv = track[i]
            i += 1
            print """note off:
    n:{}
    kk:{}
    vv:{}""".format(n,kk,vv)
            freq = 440.0 * pow(2.0, (kk - 69.0) / 12.0)
            callback(0, duration_us)
          elif (status_byte&0xf0) == 0x90 :
            kk = track[i]
            i += 1
            vv = track[i]
            i += 1
            print """note on:
    n:{}
    kk:{}
    vv:{}""".format(n,kk,vv)
            freq = 440.0 * pow(2.0, (kk - 69.0) / 12.0)
            callback(freq, duration_us)
          elif (status_byte&0xf0) == 0xa0 :
            kk = track[i]
            i += 1
            vv = track[i]
            i += 1
            print """polifonic keep pressure:
    n:{}
    kk:{}
    vv:{}""".format(n,kk,vv)
            freq = 440.0 * pow(2.0, (kk - 69.0) / 12.0)
            callback(0, tempo*(1/32.0))
            callback(freq, duration_us-tempo*(1/32.0))
          elif (status_byte&0xf0) == 0xb0 :
            cc = track[i]
            i += 1
            vv = track[i]
            i += 1
            print """control change:
    n:{}
    cc:{}
    vv:{}""".format(n,cc,vv)
            try :
              freq = 440.0 * pow(2.0, (kk - 69.0) / 12.0)
              callback(freq, duration_us)
            except NameError :
              pass
          elif (status_byte&0xf0) == 0xc0 :
            pp = track[i]
            i += 1
            print """program change:
    n:{}
    pp:{}""".format(n,pp)
          elif (status_byte&0xf0) == 0xe0 :
            mm = track[i]
            i += 1
            ll = track[i]
            i += 1
            print """pitch bend:
    n:{}
    mm:{}
    ll:{}""".format(n,mm,ll)
          else :
            print "unknown midi event:",
            print hex(status_byte), map(hex, track[i:i+8])

if __name__ == '__main__':
  def callback(freq, duration_us) :
    if 0 < freq:
      p = subprocess.Popen(["beep", "-l", str(duration_us/1000.0), "-f", str(freq)])
      p.wait()
    else :
      time.sleep(duration_us/1000.0/1000.0)

  midi_play("./20111219165842b4a.mid", callback)