Well, we used to successfully dynamically stitch a JPEG onto the front or back or middle of a video to make a VOD have an unskippable ad regardless of target device. We did that back in the Windows Media (.wmv) days, haven't tried it with H.264. But this should be easier.
We use a similar principle to generate dynamic thumbnails. Our VOD hosting customers can call a video URL with a query string specifying time offset and size and we generate a JPEG thumbnail on the fly from the closest keyframe of the H.264 file, storing the thumbnails in an intermediate cache layer. Works great, and beats keeping a bazillion thumbs managed when the source media is changed or deleted.
Generating an ad should be no harder than that. Easier, I'd think, since most of our time is spent seeking to the keyframe of a 2 hour movie.
We use a similar principle to generate dynamic thumbnails. Our VOD hosting customers can call a video URL with a query string specifying time offset and size and we generate a JPEG thumbnail on the fly from the closest keyframe of the H.264 file, storing the thumbnails in an intermediate cache layer. Works great, and beats keeping a bazillion thumbs managed when the source media is changed or deleted.
Generating an ad should be no harder than that. Easier, I'd think, since most of our time is spent seeking to the keyframe of a 2 hour movie.