[blimey]

Yes, I was able to get that session (timewarp-2012/marcel-fengler, recording 001196) in sync.

This session has 463 beat files (0000-0462). After processing them all with the BeatConvert.php script, you may notice that if you play any one individual flv file, the ending time of each individual file tracks along respective to the whole session time.

For example 0462.flv has an ending time of 132:27 (the end time of the whole session).
0461.flv has an ending time of 132:24 (where it ends relative to the whole).
And so on, for all the earlier files.

The flv containers for all of these pieces are encoded in such a way that the collection "appears" as one big individually encoded flv file to the flash player. This is due to the way they split up the original flv file. I'll spare the details about that.

Anyway, you can simply reconstruct the original flv file from all the pieces using simple binary file operations.

To put it as simply as possible, you leave 0000.flv as-is, then cut the first 32 bytes from each of the remaining files (0001.flv through 0462.flv), and then join them all together (in order) and you have the original flv in one file.

When I say join them, I mean in terms of binary file operations, not video operations.

I used "replace pioneer 2.73" to quickly do these binary file operations in a GUI, but a script could easily be constructed.

Once you have the original flv file in one piece, you can copy it to another container like mkv using ffmpeg (the best way).

Flvextract won't work on the original flv because of some anomalies in the 264 bitstream they used. And if using mp4box, some special commands are needed for the same reason. But if you just stream copy the original flv to mp4 or mkv container using ffmpeg it will work straight away. Or you can just leave the original flv alone if you can use it that way.