WEBM/MP4 video (Miro converter - 468 KB / 676 KB - not optimised for seeking)WEBM video (encoded by syncsketch - 1.5 MB - optimised for seeking)
Canvas, synced to video - seek performance depends on videoCanvas, cached from video - seek ok after cache (play through 2-3 times), chews memory, enables multi-frame features (like ghosting)