Hi, I would like to ask a question.
I'm currently modding PVZ, including music. I had a lot of Mp3 music files, so how to turn all those files into one mo3 file as PVZ music (1 mo3 file that has a lot of songs compressed in it)?
It'll be a dirty trick.
And I suggest you start with lossless or high quality compressed music to start with.
Basically, you want your music in 16 bit PCM WAV format, stereo if you want simple, mono pairs if you want to assemble them into the tracker.
What you'll be doing is loading these PCM files as samples into Open Modplug Tracker.
You'll want to make note of the original order list of the original MO3, just in case the game uses raw orders for song numbers.
You'll be recreating that order list with empty patterns, with your songs loaded as samples. Then you'll be using note on commands at the start of each subsong's order list (first pattern there) to start each song from its sample numbers, then use a combination of break to order in channel 0 and break to row in channel 1 to jump back to that exact order/row, while your music sample will either play out completely, or loop according to whatever loop settings you have applied to it.
Once you are satisfied that you have a working .XM or .IT with all of your PCM songs shoved into it, you'll be packing this with the MO3 compressor, and using Vorbis for the samples you supplied. (This is why you should start off with uncompressed high quality music.)
I would say use existing MP3 or Ogg Vorbis files, but I do not know of any way to insert existing compressed samples into an MO3.
Even if that were possible, it still doesn't handle the need to create a module template that is nearly identical in order structure to the file you'll be replacing.
We are talking about Plants vs. Zombies here, right?