Ability to set BGR of VideoFileClip

[JunweiLiang]

Currently the pix_fmt for ffmpeg is set in VideoFileClip.py via

pix_fmt = "rgba" if has_mask else "rgb24"

It would be great if VideoFileClip could accept an optional "pix_fmt" arg so that "bgr24" could be used to be consistent with OpenCV.

[Ricardo-HE]

Hi! can I work on this issue?

[tburrows13]

Yes please! It looks like there's quite a few places where "pix_fmt" appears, and it would probably be better to make all of them user-settable:

• VideoFileClip (and by extension, FFMPEG_VideoReader which already has it)
• ffmpeg_read_image()
• ffmpeg_write_image()
• VideoClip.write_videofile() (and by extension, ffmpeg_write_video() and FFMPEG_VideoWriter)

And then .write_gif(), if you like.

Note ffmpeg -pix_fmts.

Let me know if you need a hand with anything!

[Ricardo-HE]

The solution should accept any of the pixels format supported by ffmpeg? if that's the case, should I change the depth depending on the pixel format? Or did I misunderstand something?

[tburrows13]

Well you could in theory change the depth depending on the NB_COMPONENTS output from ffmpeg, but I think that that is probably overkill. I'd be happy to just assume that it is 3 unless it is rgba (or perhaps unless it ends in a to catch brga as well. This would require a comment next to that line expaining it or linking here). This is the only feature request that we've had related to pix_fmt, so I don't think that it is worth adding (and therefore maintaining) a lot of code to interface with ffmpeg to determine the depth when it isn't even required to fulfil this request. If people in the future require this feature, I wouldn't necessarily object to it, but it seems unnecessary at this point in time.