Add video utilities

[sfmig]

Is your feature request related to a problem? Please describe.
There are some video utils with ffmpeg that I use often and would be useful to wrap.

Describe the solution you'd like
A video utils module that supports:

• applying a reasonable compression to a video
• extracting frames in a video as images (selected frames, or a range of them, or all frames... ideally the input can be in frame number or in seconds).
• combining images into a video
• print out main video "specs" (most are available from ffprobe output): frame rate, codec, length in seconds, length in number of frames, frame size). See also Print video specs to terminal #11
• crop a video in time (using time in seconds or in frames)
• crop a video spatially (i.e., crop every frame)

Describe alternatives you've considered
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Additional context
Related to #4, #4 and #10

[vietluong2110]

@sfmig could you assign this issue to me ?

[adamltyson]

Hi @vietluong2110 you don't need to be assigned to an issue to work on it. Just open a draft PR as soon as you can so that other's know you're working on it.

[Edu92337]

Hi @sfmig I'd like to work on this. Should this be under ethology.io or a separate module? Any preferences on ffmpeg wrapper library?