Incorrect frame shown when placing edit cursor + playback start lag

Why is timeline-frame synchronisation inaccurate and why does video playback lag / jump frames on playback start or when seeking during playback? When I want to synchronise the impact of a sound with an action in the video I always need to place the edit cursor few seconds before the frame of contact and advance with a hotkey action frame by frame until I reach the right frame to be sure that the still image on the video player portrays the frame of contact at the right point in time and I can place the audio transient correctly. And when checking playback I also need to place the edit cursor a few seconds in advance of the part I want to check because usually the first few frames are not displayed correctly - the display is fixed at some random frame (as explained before) and when starting playback it remains at this frame or jumps shortly to another random frame and few seconds (or milliseconds) into playback it recovers and playback runs smoothly. I don't know if I explained this well and if others have this problem too or it is just on my end.. but is it possible to fix this so that when I place the cursor somewhere in the timeline the correct frame is reliably shown and when starting playback the video starts immediately and exactly at that frame and not do some random flicker? I want to be able to trigger both video and audio exactly on hit/transient (or very shortly before) and see whether the impact works correctly, without those previously mentioned workarounds. It just feels a bit fiddly working with the video engine.

Ah, yeah, fixing some of this!

GPU support?

Just some bugs fixed! Try the latest +dev build (pre-release forum), if you like!

@Phazma, may I ask what kind of encoding you are using for your videos? I'm doing this for quite some time now in Reaper and never had the issue, that frames don't show correctly. It was quite an odyssey for me to find the right video format (for DAWs in general, not Reaper in particular), but what you would want in general is a video that encodes EVERY frame separetly, that means, the video shouldn't use B or P-Frames, because those need to be calculated depending on the previous / next frames. That's why I always request videos from editors that have every frame encoded indepedently. Anyway, sorry for stating the obvious if you are already following all these things. But just checking!