Try turning off the cache just to see if that affects the start time, --cache=no. This would only be an issue if the file loading is slow.
Otherwise try running it with strace to see what's happening during the dead time. strace mpv <filename>
Try turning off the cache just to see if that affects the start time, --cache=no. This would only be an issue if the file loading is slow.
Otherwise try running it with strace to see what's happening during the dead time. strace mpv <filename>