[REQ] FFMPEG's video capture (as input) support

[MarcoRavich]

Hi there, 1st of all thanks for your work !

Even if it probably don't falls within the project scope, it would be extremely interesting to implement FFMPEG video capture as input.

We've got inspired by How to capture, deinterlace, and encode analog video git which proposes an interesting method on how to set FFMPEG for video capture through dedicated hardware.

The most interesting (and recently made) resource is probably Video Capture wrapper for FFMPEG with Software/Hardware decoding and there's also vcr or - a bit dated - git where "video capture, live feed display, and recording to an AVI file when recording activated"_ where implemented through FFMPEG in Video capture and archiving utility for Linux.

If it helps to let you implement it easier, here are some simple FFMPEG capture scripts to get inspiration from:

• A collection of scripts to capture video with ffmpeg-python
• FFMPEG scripts
• FFMPEG-Capture

Last but not least capture-device-list or ffmpeg-devices may also help.

Hope that inspires !