pyav_reader.py: object has no attribute 'long_name' when trying to inspect 'frame'

[rodrigo-j-goncalves]

I have PIMS 0.6.1 installed with pip on Linux.

I am following trackpy's walkthrough notebook, trying to use my own mp4 video as input.

I open the video using the suggested pipeline:

@pims.pipeline
def gray(image):
    return image[:, :, 1]  # Take just the green channel

frames = gray(pims.open('/test/test_001.mp4'))

When I try to inspect the video as shown in the notebook (ie using the instruction frame), I get the following error:

File av/stream.pyx:112, in av.stream.Stream.__getattr__()
AttributeError: 'av.video.codeccontext.VideoCodecContext' object has no attribute 'long_name'

Just in case I also tried opening the file without the pipeline, using:
frames = pims.as_grey(pims.open('/test/test_001.mp4'))

But I get the same error. This error is not present when I open an image sequence (maybe because in that case PIMS uses another plugin?). I have originally posted this as a trackpy issue and the problem might be related to PyAv version (I am using PyAv ver 10.0.0 and according to this comment it should work with the previous stable version, 9.0.2)

---

Full output with the error message:

AttributeError                            Traceback (most recent call last)
File ~/.virtualenvs/VirtEnvRG001_daily/lib/python3.10/site-packages/IPython/core/formatters.py:708, in PlainTextFormatter.__call__(self, obj)
    701 stream = StringIO()
    702 printer = pretty.RepresentationPrinter(stream, self.verbose,
    703     self.max_width, self.newline,
    704     max_seq_length=self.max_seq_length,
    705     singleton_pprinters=self.singleton_printers,
    706     type_pprinters=self.type_printers,
    707     deferred_pprinters=self.deferred_printers)
--> 708 printer.pretty(obj)
    709 printer.flush()
    710 return stream.getvalue()

File ~/.virtualenvs/VirtEnvRG001_daily/lib/python3.10/site-packages/IPython/lib/pretty.py:410, in RepresentationPrinter.pretty(self, obj)
    407                         return meth(obj, self, cycle)
    408                 if cls is not object \
    409                         and callable(cls.__dict__.get('__repr__')):
--> 410                     return _repr_pprint(obj, self, cycle)
    412     return _default_pprint(obj, self, cycle)
    413 finally:

File ~/.virtualenvs/VirtEnvRG001_daily/lib/python3.10/site-packages/IPython/lib/pretty.py:778, in _repr_pprint(obj, p, cycle)
    776 """A pprint that just redirects to the normal repr function."""
    777 # Find newlines and replace them with p.break_()
--> 778 output = repr(obj)
    779 lines = output.splitlines()
    780 with p.group():

File ~/.virtualenvs/VirtEnvRG001_daily/lib/python3.10/site-packages/slicerator/__init__.py:466, in Pipeline.__repr__(self)
    463 anc_str = ", ".join(type(a).__name__ for a in self._ancestors)
    464 msg = '({0},) processed through {1}. Original repr:\n    '.format(
    465     anc_str, self._proc_func.__name__)
--> 466 old = [repr(a).replace('\n', '\n    ') for a in self._ancestors]
    467 return msg + "\n    ----\n    ".join(old)

File ~/.virtualenvs/VirtEnvRG001_daily/lib/python3.10/site-packages/slicerator/__init__.py:466, in <listcomp>(.0)
    463 anc_str = ", ".join(type(a).__name__ for a in self._ancestors)
    464 msg = '({0},) processed through {1}. Original repr:\n    '.format(
    465     anc_str, self._proc_func.__name__)
--> 466 old = [repr(a).replace('\n', '\n    ') for a in self._ancestors]
    467 return msg + "\n    ----\n    ".join(old)

File ~/.virtualenvs/VirtEnvRG001_daily/lib/python3.10/site-packages/pims/pyav_reader.py:267, in PyAVReaderTimed.__repr__(self)
    257     def __repr__(self):
    258         # May be overwritten by subclasses
    259         return """<Frames>
    260 Format: {format}
    261 Source: {filename}
    262 Duration: {duration:.3f} seconds
    263 Frame rate: {frame_rate:.3f} fps
    264 Length: {count} frames
    265 Frame Shape: {frame_shape!r}
    266 """.format(frame_shape=self.frame_shape,
--> 267            format=self._stream.long_name,
    268            duration=self.duration,
    269            frame_rate=self.frame_rate,
    270            count=len(self),
    271            filename=self.file)

File av/stream.pyx:112, in av.stream.Stream.__getattr__()

AttributeError: 'av.video.codeccontext.VideoCodecContext' object has no attribute 'long_name'