The docs say that audiolab is for spectrograms. I don't think this should be a critical feature for audio uploading and transcoding to work. It is possible that I'm missing something and audiolab is more important than I thought though. When I upload a flac file without audiolab installed I get the following error:

2013-04-03 22:11:30,136 ERROR   [celery] Task mediagoblin.processing.task.ProcessMedia[c1ac8460-95b5-44bc-bc5d-f02a9204be1b] raised exception: NameError("global name 'audiolab' is not defined",)
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/celery/execute/trace.py", line 181, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/usr/share/mediagoblin/mediagoblin/processing/task.py", line 92, in run
    entry.media_manager['processor'](proc_state)
  File "/usr/share/mediagoblin/mediagoblin/media_types/audio/processing.py", line 122, in process_audio
    fft_size=audio_config['spectrogram_fft_size'])
  File "/usr/share/mediagoblin/mediagoblin/media_types/audio/transcoders.py", line 76, in spectrogram  
    numpy.hanning)
  File "/usr/share/mediagoblin/mediagoblin/media_types/audio/audioprocessing.py", line 109, in __init__
    max_level = get_max_level(input_filename)
  File "/usr/share/mediagoblin/mediagoblin/media_types/audio/audioprocessing.py", line 79, in get_max_level
    audio_file = audiolab.Sndfile(filename, 'r')
NameError: global name 'audiolab' is not defined

It works fine if you add a comma at the end.

backtrace:

Traceback (most recent call last):
  File "/usr/bin/paster", line 4, in <module>
    command.run()
  File "/usr/lib/python2.7/dist-packages/paste/script/command.py", line 104, in run
    invoke(command, command_name, options, args[1:])
  File "/usr/lib/python2.7/dist-packages/paste/script/command.py", line 143, in invoke
    exit_code = runner.run(args)
  File "/usr/lib/python2.7/dist-packages/paste/script/command.py", line 238, in run
    result = self.command()
  File "/usr/lib/python2.7/dist-packages/paste/script/serve.py", line 284, in command
    relative_to=base, global_conf=vars)
  File "/usr/lib/python2.7/dist-packages/paste/script/serve.py", line 321, in loadapp
    **kw)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 247, in loadapp
    return loadobj(APP, uri, name=name, **kw)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 272, in loadobj
    return context.create()
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 710, in create
    return self.object_type.invoke(self)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 203, in invoke
    app = context.app_context.create()
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 710, in create
    return self.object_type.invoke(self)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 144, in invoke
    **context.local_conf)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/util.py", line 56, in fix_call
    val = callable(*args, **kw)
  File "/usr/lib/python2.7/dist-packages/paste/urlmap.py", line 25, in urlmap_factory
    app = loader.get_app(app_name, global_conf=global_conf)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 350, in get_app
    name=name, global_conf=global_conf).create()
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 710, in create
    return self.object_type.invoke(self)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 229, in invoke
    filtered = context.next_context.create()
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 710, in create
    return self.object_type.invoke(self)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/loadwsgi.py", line 146, in invoke
    return fix_call(context.object, context.global_conf, **context.local_conf)
  File "/usr/lib/python2.7/dist-packages/paste/deploy/util.py", line 56, in fix_call
    val = callable(*args, **kw)
  File "/usr/share/mediagoblin/mediagoblin/app.py", line 254, in paste_app_factory
    mgoblin_app = MediaGoblinApp(mediagoblin_config)
  File "/usr/share/mediagoblin/mediagoblin/app.py", line 67, in __init__
    global_config, app_config = setup_global_and_app_config(config_path)
  File "/usr/share/mediagoblin/mediagoblin/init/__init__.py", line 53, in setup_global_and_app_config
    raise ImproperlyConfigured(validation_report)
mediagoblin.init.ImproperlyConfigured: There were validation problems loading this config file:
--------------------------------------------------------
mediagoblin:media_types = the value "mediagoblin.media_types.image" is of the wrong type.
Removing PID file /home/mediagoblin/mediagoblin.pid

Because of this issue I have installed X server and latest chromium browser on my home Archlinux based server. I can played the attached test.webm file directly on the chromium instance on my server without a problem. But after uploading the same test.webm file to my mediagoblin installation (on the same server) embedded video player produces only sound - no video.

Please use an attached test.webm file for testing purposes.

So, I suspect this could be a transcoding problem (Yes this test.webm filie was transcoded).