[FEATURE ⭐] Ability to set keyframes frequency

[Salmondx]

Is your feature request related to a problem? Please describe. 📝
Currently there is no way to set the keyframe frequency on a video encoder. This leads to a very slow seek times since there are 32 P frames in between I frames by default. Would be great to have an ability to set a GOP size for use cases when videos need to be frequently seeked.

Describe the solution you'd like 🔑
Ability to set keyframes frequency on video encoder.

[NiiightmareXD]

This feature is not available in the Windows API encoder. I may add support for an FFmpeg encoder, but in the meantime, you can use an FFmpeg wrapper to access its encoder, which I believe supports what you want.