Source Code for Module soundplayer

  1  # soundplayer.py 
  2   
  3  import thread 
  4  import os 
  5  import time 
  6  import sys 
  7   
  8  sys.excepthook = None  # avoid error message in playTone() 
  9   
 10 -class SoundPlayer: 
 11      ''' 
 12      Sound player based on SoX, called "the Swiss Army knife of sound processing programs" by its developper. 
 13      This simple Python wrapper is based on Linux shell commands running in extra threads.  
 14      For the Raspberry Pi the following installation are needed: 
 15      sudo apt-get install sox 
 16      sudo apt-get install mp3 
 17      ''' 
 18      @staticmethod 
 19 -    def playTone(frequencies, duration, blocking = False, device = 0): 
 20          ''' 
 21          Plays one or several sine tones with given frequencies and duration. 
 22          @param frequencies: the frequency or a list of several frequencies in Hz 
 23          @param duration: the duration in s 
 24          @param blocking: if True, the functions blocks until playing is finished; otherwise it returns immediately (default: False) 
 25          @param device: the sound device ID (e.g. 0: standard device, 1: USB sound adapter) 
 26          ''' 
 27          if not type(frequencies) == list: 
 28              frequencies = [frequencies] 
 29          if blocking: 
 30              SoundPlayer._emit(frequencies, duration, device) 
 31          else: 
 32              thread.start_new_thread(SoundPlayer._emit, (frequencies, duration, device)) 
 33   
 34      @staticmethod 
 35 -    def isPlaying(): 
 36          ''' 
 37          Checks if the sound is still playing. 
 38          @return: True, if the sound is playing; otherwise False 
 39          ''' 
 40          info = os.popen("ps -Af").read() 
 41          process_count = info.count("play") 
 42          return process_count >= 2 
 43   
 44      @staticmethod 
 45 -    def _emit(frequencies, duration, device): 
 46          s = " " 
 47          for f in frequencies: 
 48              s += "sin " + str(f) + " " 
 49          cmd = "AUDIODEV=hw:" + str(device) + " play -q -n synth " + str(duration) + \ 
 50              s + " 2> /dev/null"  
 51          os.system(cmd) 
 52           
 53 -    def __init__(self, audiofile, device = 0): 
 54          ''' 
 55          Creates a sound player to play the given audio file (wav, mp3, etc.)  
 56          to be played at given device ID. Throws exception, if the sound resource is not found. 
 57          @param audiofile: the sound file to play 
 58          @param device: the sound device ID (e.g. 0: standard device, 1: USB sound adapter) 
 59          ''' 
 60          if not os.path.isfile(audiofile) : 
 61              raise Exception("Audio resource " + audiofile + " not found") 
 62          self.audiofile = audiofile 
 63          self.device = device 
 64    
 65      @staticmethod 
 66 -    def _run(cmd): 
 67          os.system(cmd) 
 68   
 69 -    def play(self, volume = 1, blocking = False): 
 70          ''' 
 71          Plays the sound with given volume (default: 1). The function returns immediately. 
 72          @param volume: the sound level (default: 1) 
 73          @param blocking: if True, the functions blocks until playing is finished; otherwise it returns immediately (default: False) 
 74          ''' 
 75          self.volume = volume 
 76          cmd = "AUDIODEV=hw:" + str(self.device) + \ 
 77              " play -v " + str(self.volume) + \ 
 78              " -q " + self.audiofile + " 2> /dev/null" 
 79   
 80          if blocking: 
 81              self._run(cmd) 
 82          else: 
 83              thread.start_new_thread(SoundPlayer._run, (cmd,)) 
 84       
 85      @staticmethod 
 86 -    def stop(): 
 87          ''' 
 88          Stops playing. 
 89          ''' 
 90          cmd = "sudo killall -9 play" 
 91          thread.start_new_thread(SoundPlayer._run, (cmd,)) 
 92          time.sleep(0.5)  # Wait until process is killed 
 93   
 94      @staticmethod 
 95 -    def pause(): 
 96          ''' 
 97          Pauses playing momentarily. 
 98          ''' 
 99          cmd = "sudo pkill -STOP play" 
100          thread.start_new_thread(SoundPlayer._run, (cmd,)) 
101   
102      @staticmethod 
103 -    def resume(): 
104          ''' 
105          Resumes playing (after it has been stopped). 
106          ''' 
107          cmd = "sudo pkill -CONT play" 
108          thread.start_new_thread(SoundPlayer._run, (cmd,)) 
109