Hi there!
I'm newbie with OpenMPT and with a low English skill :o
Let's try to explain my problem...
By default, if you play different notes (C5, D5, E5), both Pitch and Time of a sample are altered.
Are there options / params that could avoid time modifications?
My goal is to have all samples with the same duration and only pitch modifications while playing notes.
Thanks.
No, this is not possible. This would require time-stretching and although OpenMPT has had this in the past (don't know for sure if its still there but I don't think I saw it last time) the time-stretching is low quality as there's a lot to calculate.
(correct me if I'm wrong Saga_Musix)
It is technically impossible to create perfect pitch shifting. And the pitch shifting library for offline processing that is used by OpenMPT is not exactly of high quality - but it doesn't matter, even the higher quality ones like Rubberband are still not perfect and are released under incompatibile licenses. So basically, if you need pitch shifting, do it offline, either using the built-in tools or using something like Rubberband for even higher quality.
Edit: Oh, and of course this is a big patent minefield too that I'm not going to touch.