NEGIMAN4'S PROFILE

author=Jude
I figured this out as soon as I noticed the RTP's BGMs loop and started inspecting the files. Use WinVorbis or the audio editor of your choice (that supports metatag editing, of course) to add custom metadata tags to the OGG file (the "other tags" tab). The custom tags you'll want to add are called loopstart and looplength. The value is expressed in samples rather than seconds, so take the starting point of the loop in seconds and multiply it by the sample rate (32.98 seconds * 44100 Hz, for example, but your sampling rate might be different). Looplength is the same, but it is a duration. Take the end point of the loop and subtract the starting point (again, in seconds), then multiply that difference by the sampling rate.

This will work in anything configured to read these metadata tags, though your standard media players usually aren't.

As an example, here is what Battle2.ogg and its metadata tags look like inside of WinVorbis:

In this example, the loopstart is at 7.84 seconds (345544 / 44100 = 7.84)
The loop duration, or loop length is 69.57 seconds, such that the BGM repeats between 7.84 and 77.41 seconds.

Finding the precise times might be difficult. It's fairly easy for me because I can just grab those points in FL Studio when I'm creating the music. But if you're trying to loop something that's already been encoded, you'll probably have to approximate or look closely at the raw waveform to identify a particular drum beat/amplitude spike.

Make sense?