Comment by zahlman

>Its CLI has a certain logic to it... it's order dependent (not all unix CLIs are).

Which is appropriate. A Unix pipeline is dependent on the order of the components, and complex FFMpeg invocations entail doing something analogous.

>I ended up using ffmpeg-python which composes the command line from this

A lot of people like this aesthetic, but doing "fluent" interfaces like this is often considered un-Pythonic. (My understanding is that ffmpeg-python is designed to mirror the command-line order closely.) The preference (reinforced by the design of the standard library and built-in types) is to have strong https://en.wikipedia.org/wiki/Command%E2%80%93query_separati... . By this principle, it would look something more like

  ffmpeg(global_args=..., overwrite_output=True).process_async(piped_input(...), output(...))

where using a separate construction process for the input produces a different runtime type, which also cues the processing code that it needs to read from stdin.