title: how to load m4a file in python
body: <p>Is there an easy way to load m4a sound file in python. I've came across audiotools lib but I'm getting an error while using <code>to_pcm</code> fn</p>
  
  <pre><code>audiotools.open('file.m4a').to_pcm()
  
  ---------------------------------------------------------------------------
  FileNotFoundError                         Traceback (most recent call last)
  &lt;ipython-input-76-e12405d92ce3&gt; in &lt;module&gt;()
  ----&gt; 1 audiotools.open(p).to_pcm()
  
  /path/to/m4a.py in to_pcm(self)
      456             stdout=subprocess.PIPE,
      457             stderr=subprocess.DEVNULL if hasattr(subprocess, "DEVNULL") else
  --&gt; 458             open(os.devnull, "wb"))
      459         return PCMFileReader(sub.stdout,
      460                              sample_rate=self.sample_rate(),
  
  /path/to/subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo,    creationflags, restore_signals, start_new_session, pass_fds, encoding, errors)
      705                                 c2pread, c2pwrite,
      706                                 errread, errwrite,
  --&gt; 707                                 restore_signals, start_new_session)
      708         except:
      709             # Cleanup if the child failed starting.
  
  /path/to/subprocess.py in _execute_child(self, args, executable, preexec_fn, close_fds, pass_fds, cwd, env, startupinfo, creationflags, shell, p2cread, p2cwrite,    c2pread, c2pwrite, errread, errwrite, restore_signals, start_new_session)
     1331                             else:
     1332                                 err_msg += ': ' + repr(orig_executable)
  -&gt; 1333                     raise child_exception_type(errno_num, err_msg)
     1334                 raise child_exception_type(err_msg)
     1335 
  
  FileNotFoundError: [Errno 2] No such file or directory: 'faad'
  </code></pre>