How to play transparent video

[wheelerkft]

As I can see, the 0.40 version can play trasparent videos just fine. However, up to version 0.38 there was a -alpha=yes parameter and then the video displayed was really transparent, with the desktop in the background. In version 0.40, on the other hand, it is displayed either with a gray and white background or with the color defined by background-color.

Is it possible to display the video in such a way that the transparent parts are really transparent?

[guidocella]

https://mpv.io/manual/master/#options-background

[guidocella]

Try --gpu-api=opengl

[wheelerkft]

Option gpu-api: 'opengl' isn't supported.
Error parsing option gpu-api (option parameter could not be parsed)
Setting commandline option --gpu-api=opengl failed.
Exiting... (Fatal error)

macOS: 15.3.2
mpv 0.40
ffmpeg 7.1.1

[guidocella]

I have no idea if it works on macOS.

[Akemi]

in the old cocoa backend (removed in 0.37) we had explicit support for this (https://github.com/mpv-player/mpv/blob/release/0.36/video/out/opengl/context_cocoa.c#L140-L141). support was never explicitly added to either libmpv/cocoa-cb, nor macvk. if it happened to work, it might have been a coincidence.

anyway it sounds like you used vo=libmpv before (the old default) and are using the new macvk backend with gpu/gpu-next now (new default). eg try --vo=libmpv.

also feel free to open an issue or feature request. a sample file would also be good in that case.

[Bellavene]

It worked for me one time on macos, when I've set it to non-native full screen by accident. Even forgot about the existence of this, so was surprised.