Constant libmpv_sys::mpv_event_id_MPV_EVENT_VIDEO_RECONFIG

pub const mpv_event_id_MPV_EVENT_VIDEO_RECONFIG: mpv_event_id = 17;

Happens after video changed in some way. This can happen on resolution changes, pixel format changes, or video filter changes. The event is sent after the video filters and the VO are reconfigured. Applications embedding a mpv window should listen to this event in order to resize the window if needed. Note that this event can happen sporadically, and you should check yourself whether the video parameters really changed before doing something expensive.