DPCM sample editor
There is a simple DPCM sample editor available from
the DPCM instrument editor,
it's intended mainly for trimming silent parts from the beginning and end of samples.
Other types of edits should be done preferably before the sample is
converted to DPCM.

Use the sample area to select a part of the sample and to set the
start position (for preview).
- Delete
Removes a part of the sample, select the part you wish to remove and press delete. This works best on the
beginning and end of a sample; if you need to remove something in the middle
then it's usually better to do this on the sample before you convert it to DPCM.
- Tilt
Inserts zero-value samples
inside a selected area, causing the sample to tilt toward zero. The idea is to
restore the delta counter back to zero when the sample
has finished, in order to restore volume for the triangle and noise channels.
- Center wave
Draws the sample with an initial delta counter value of 64 in order to center the start of the wave.
This is another method to keep the triangle and noise volume consistent, make
sure all samples starts and ends at 64.
The sample itself is not affected by this option, the equal operation in the
tracker is to use the effect Z40 when playing the sample.
- Play
Previews the sample at the selected pitch.
The offset value tells the start position (as used internally by
the DPCM channel), this value can be used with the
Yxx command.
The pos value is the position in size units as used by the DPCM channel.