The Ooyala Player has an option to preload the video content. This will typically preload 30s of video content. This is most beneficial for non-autoplaying implementations, but it is also useful in autoplayed videos when ad transitions are involved. This is because this setting will also enable preloading content during the fourth quartile of the ad break.
With Google IMA (only), we support preloading ads with the preloadAds page-level param. This enables faster startup and ad-to-content transitions. For more, see here.