I made a live musical film and I want to transcode it onto DVD.
I used FCPX and I exported it to a .mov file (166Gb) - put it into Encore, set my markers ...and everything went fine.
But after checking the video quality on a TV screen, I decided to try to improve it, so I sent the .mov file into Compressor 4 and got a m2v file.
Back into Encore, I cannot set my markers precisely, it leaves a gap between timeline bars and I cannot set it precisely where I want, which is annoying because I need markers to start right a the beginning of a song.
m2v files are long GOP files, with (depending on your settings, but the default is) an i-frame every 15 frames. That means twice a second. The rest of the frames are interpretive, either forwards or backwards. They do not contain all the information like the i-frames do.
After encoding, Encore does not let you put a marker on anything other than an i-frame, so you can't do frame accurate marking anymore.
That's one reason why markers can not be put where you want it.
Hope this helps,