[FFmpeg-user] Why is format=rgb24 required after maskedmerge?
Carl Eugen Hoyos
ceffmpeg at gmail.com
Wed Aug 19 20:55:54 EEST 2020
Am Di., 18. Aug. 2020 um 14:44 Uhr schrieb Michael Koch
<astroelectronic at t-online.de>:
> c:\ffmpeg\ffmpeg -i red.mp4 -i yellow.mp4 -i mergemap.png -lavfi
> -y out.mp4
> This works fine and the output video looks as expected. My
> question is why "format=rgb24" is required
I believe it was already explained why it really is required in this case.
Also important to mention imo is that in general, the automatic pix_fmt
conversion cannot always succeed, the system as a whole is not and
cannot be clairvoyant.
Therefore, for a sufficiently complex filter-chain, you have to force
conversions with format because without it, the conversion decisions
may be wrong (or at least not optimal).
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