How to make imageio work nice on systems with no internet connection?

[almarklein]

Right now, imageio downloads external dependencies (the freeimage library, the avbin library, and the freeimage exe) at runtime, and caches them in the appdata directory. This keeps imageio lightweight and only fetches these rather large files when needed.

However, for people working in an environment with no internet connection, this makes makes imageio much less useful. We should aim to at least get the freeimage library available. And perhaps also some of our image suite.

[almarklein]

Just to kick it off. Here are some options:

• Download libs at runtime (current solution)
• Download libs at install time (apparently also not very robust)
• Distribute platform specific lib with dist package. This means we'd have to provide a dist package for each platform.
• Provide two dist packages. One with source only, and one that contains the lib for all platforms, for those who cannot rely on an Internet connection. We definitely don't want to do this for ffmpeg.

Question:

• For the cases with no Internet connection, would it be acceptable for some plugins not to work? For ffmpeg we can also use the system installed.

[blink1073]

I'd vote to have a source-only version, and wheels for 64 bit Linux, Windows, and OSX with just the freeimage support. Rather that auto-downloading, it would be nice to present the user with the option of whether to download an external lib, perhaps as a simple Tk dialog. I think partial functionality is fine in this case given the nature of the library.

[sametmax]

You can make plugins optionals.

pip install imageio (or python setup.py) would install the simple version.

pip install imageio[pluginname, pluginname] install imageio with the desired plugins.

You can use extras_require for this :

https://pythonhosted.org/setuptools/setuptools.html#declaring-extras-optional-features-with-their-own-dependencies

[almarklein]

I'd vote to have a source-only version, and wheels for 64 bit Linux, Windows, and OSX with just the freeimage support.

@blink1073 I've made some progress in this direction, but get into a problem: Wheel sees that imageio is pure Python and thus the resulting wheels get a name that indicates its cross-plaform. I've asked the wheel guys about a possible solution: https://bitbucket.org/pypa/wheel/issue/128

Another solution would be to pack the 64bit libs for osx/win/linux into a single cross-platform wheel. Together these 3 libs take up 12.8 MB. Not an ideal solution, but it might be acceptable if we do not find a solution for the above problem. WDYT?

[blink1073]

Rather than bundled all together they could be made available for download on Github. In my experience as long as I could go download one file and install it in the lab, it would be doable.

[almarklein]

Now I am confused :) if you can download that file by hand, why can imageio not download it for you automatically?

[blink1073]

Portable harddrives work as long as the installation does not have a dependency trail.

[almarklein]

Ah, right. Makes sense. Nevertheless, shipping freeimage in the dist distribution is still something wanted for e.g. Debian building (#40). So I will first try some more in that direction ...

[ghisvail]

FYI, freeimage is available in Debian [1]. But this issue summarizes the problem I faced with the Debian package, i.e. the need to perform a complete build / install / test / clean of the package, without relying on downloading any external resources.

[1] https://packages.debian.org/source/sid/libs/freeimage

[almarklein]

@blink1073 and @ghisvail I have now implemented an approach that creates additional platform-specific archives for pypi. An example: https://testpypi.python.org/pypi/imageio/1.0.0.9.7dev

Also there is python setup.py build_with_fi install to download the freeimage library and some images required during testing at build-time.

Please let me know if this would cover your needs.

[almarklein]

See #45

[blink1073]

@almarklein, looks good to me (just having viewed the diff)