Hi
I've searched long and hard for either a hardware or software video player capable of outputting midi information and haven't yet come across one, so would be very interested to learn of one if one exists that anyone knows of. The 3D view examples in the link you provided though again all seem to be created from an audio file and not a video file. Synching to an audio file isn't so much of a problem, it's the video element of SX that causes the issue.
I totally understand your reluctance to create a more accurate timeline option given the size of the job and also the technicalities involved in doing so. However, I think there are a few options worth considering in answer to your comments -
design and embed our own media player in the software
There are several open source media players available without usage restrictions that could possibly be utilised, for example this one
https://www.videolan.org/ It exposes a very usable API (details here
https://www.videolan.org/developers/vlc/doc/doxygen/html/modules.html) and although it wouldn't be a small task to embed and use it in SX, I'd imagine it would be a lot easier than writing your own from scratch
include Codecs to read compressed formats (nightmare because so many different existing formats)
The media player linked to above includes all popular codecs, but for any other the excellent K-Lite codec pack
http://www.codecguide.com/download_kl.htm covers just about all of them
load the media file in RAM (not suitable for "slow" computers)
Totally understand, however even the most basic PC's these days are spec'd high enough to handle the job I'd have thought. Another option would be to make it a user definable choice as to whether to load into RAM or not, and if they were having problems loading media into RAM due to a slower or underspec'd machine, use your existing method of letting the operating system deal with the media.
Yet another option might be to release two versions of ShowXpress, Pro and Lite where Lite would be the existing free version and Pro would be paid for version that included more accurate video synch, and other options not available in the Lite version. I know I for one would be more than happy to pay for the software, either as standalone or bundled into a deal with Chauvet when buying the interface if it did what we needed re video synch. At least that way you'd get some return for the amazing amount of time and effort you clearly put into the software
I've mentioned a couple of times in this thread (I think) that I truly believe ShowXpress has the potential to be world beating software with a few additions and tweaks and I'm in no way criticizing what you've already created, and I really hope that coming up with a solution to the synching issue could be considered something of a priority as it's definitely one area of a very useable system that lets it down in my opinion