..or at least some advice, I can see quite a lot of people involved with Sonic submissions.
As some of you may have noticed, I'm currently working on Genesis console verifications. There are games that work right away, there are others that desync even before menus, and there are some that work after some input tweaking. Sonic games are in that third category.
I've started with Sonic1, and it was not syncing, but was quite easy to fix. The reason for those desyncs seems to be that Gens does poor job emulating latencies caused by loading graphics into VRAM, so things go a bit faster in Gens then in the real thing. This could be fixed by inserting some no-input frames in level transitions; main symptom was that Sonic would not do his initial jump at the start of some level (all movement is started with jump in S1 to gain speed, as there is no spindash). So the process was to just insert a frame, play and see how it goes, which was a bit time consuming at the end of the game as there is no easy way to speed up real hardware or load a savestate (had to play the same thing full length each time), but I did it in background while doing other stuff at the PC, so it was ok and worked out in the end.
Now with later Sonic games starting from 2, things become more complicated. The games tend to load stuff mid-level a lot more, and that is causing desyncs, but they can be solved the same old way. However those extra frames seem to affect some objects in the game, like moving platforms, which end up in different positions. See screenshots below:
GhostSonic had the same issue with Sonic2, I'm also getting desync at the same place, haven't checked in detail but it's probably also the same issue.
http://tasvideos.org/forum/viewtopic.php?p=366845#366845
So the question is, if parts of the movie with different object phases would be redone, would remaining levels of the game sync? To put it differently, are Sonic games sensitive to early input changes so much that later levels would desync?
If later levels can be synced, would anyone be willing to rework sections of the movie with different object placements? I think it should be possible to recreate object phases in the emulator by keeping Sonic idle for some frames at the start of the level. I'd just need some TASer to re-run those sections in an optimal way (I have no experience in that area to do it myself), while I could provide a gmv (or bkm) which runs upto the object so it's in hardware-compatible phase.
So the first time score counter shows it's 7 lag + 2 mine, meaning others come from level transition. Can't check other points using this method as the score counter doesn't update anywhere else.
So the difference seems to be 31.
(also it seems my camera scans bottom-to-top, what's up with that?)
