[No such file or directory error] when running documentation examples

[wangsix]

I probably missed something very basic. So I was trying to test the muda code examples from the documentation as follows.

jams_obj = muda.load_jam_audio(jam_file, song_file)
pitch = muda.deformers.LinearPitchShift(n_samples=5, lower=-2, upper=2)

for i, jam_out in pitch.transform(jams_obj):
    muda.save('output_{:02d}.wav'.format(i),
              'output_{:02d}.jams'.format(i),
               jam_out)

and I encountered the following error message:

---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
<ipython-input-11-589bfe4aecc5> in <module>()
----> 1 for i, jam_out in pitch.transform(jams_obj):
      2     muda.save('output_{:02d}.ogg'.format(i),
      3               'output_{:02d}.jams'.format(i),
      4                jam_out)

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/muda/base.pyc in transform(self, jam)
    141 
    142         for state in self.states(jam):
--> 143             yield self._transform(jam, state)
    144 
    145     @property

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/muda/base.pyc in _transform(self, jam, state)
    109 
    110         if hasattr(self, 'audio'):
--> 111             self.audio(jam_w.sandbox.muda, state)
    112 
    113         if hasattr(self, 'metadata'):

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/muda/deformers/pitch.pyc in audio(mudabox, state)
     75         mudabox._audio['y'] = pyrb.pitch_shift(mudabox._audio['y'],
     76                                                mudabox._audio['sr'],
---> 77                                                state['n_semitones'])
     78 
     79     @staticmethod

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyrubberband/pyrb.pyc in pitch_shift(y, sr, n_steps, rbargs)
    163     rbargs.setdefault('--pitch', n_steps)
    164 
--> 165     return __rubberband(y, sr, **rbargs)

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyrubberband/pyrb.pyc in __rubberband(y, sr, **kwargs)
     64         arguments.extend([infile, outfile])
     65 
---> 66         subprocess.check_call(arguments)
     67 
     68         # Load the processed audio.

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in check_call(*popenargs, **kwargs)
    533     check_call(["ls", "-l"])
    534     """
--> 535     retcode = call(*popenargs, **kwargs)
    536     if retcode:
    537         cmd = kwargs.get("args")

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in call(*popenargs, **kwargs)
    520     retcode = call(["ls", "-l"])
    521     """
--> 522     return Popen(*popenargs, **kwargs).wait()
    523 
    524 

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags)
    708                                 p2cread, p2cwrite,
    709                                 c2pread, c2pwrite,
--> 710                                 errread, errwrite)
    711         except Exception:
    712             # Preserve original exception in case os.close raises.

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in _execute_child(self, args, executable, preexec_fn, close_fds, cwd, env, universal_newlines, startupinfo, creationflags, shell, to_close, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite)
   1333                         raise
   1334                 child_exception = pickle.loads(data)
-> 1335                 raise child_exception
   1336 
   1337 

OSError: [Errno 2] No such file or directory

Please give me any pointers on what I have been missing... I checked the content of jams_obj and the audio is loaded.

[bmcfee]

Yikes, that's the least helpful error message I've ever seen.

The first thing I can think of: do you have rubberband installed and in your path?

[wangsix]

Thank you so much Brian! Rubberband was not installed as you said. Thank you for pointing that out for me. Now the same code returns the following:

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-6-ba2efbb97ebe> in <module>()
----> 1 for i, jam_out in pitch.transform(jams_obj):
      2     muda.save('output_{:02d}.wav'.format(i),
      3               'output_{:02d}.jams'.format(i),
      4                jam_out)

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/jams/core.pyc in __getitem__(self, key)
    262     def __getitem__(self, key):
    263         """Dict-style interface"""
--> 264         return self.__dict__[key]
    265 
    266     def __setattr__(self, name, value):

KeyError: 0

I could only guess am I using the generator in a wrong way?

[bmcfee]

Oh, I think maybe that iterator should be wrapped as enumerate(pitch.transform(jams_obj))?

(Currently on mobile, otherwise would test it myself)

[wangsix]

You are right! I should have spot that as well. Just FYI, I was lazily copying the code from the documentation. I just added enumerate() and it worked! Thank you!

[bmcfee]

Glad it's working, and sorry for the incorrect example code! I'll fix it when I'm back on a real machine.

Alternately, a PR would be greatly appreciated if you want to take a stab at it.

Thanks for pointing this out!

[wangsix]

No problem, I will do a PR later!

On Feb 26, 2016, at 15:51, Brian McFee notifications@github.com wrote:

Glad it's working, and sorry for the incorrect example code! I'll fix it when I'm back on a real machine.

Alternately, a PR would be greatly appreciated if you want to take a stab at it.

Thanks for pointing this out!

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Reply to this email directly or view it on GitHub.

[bmcfee]

I'm closing this one out -- I think the original cause of this report is better handled within pyrubberband.