0001830: If "Use Amiga resampler for Amiga modules" is set, new .MODs use Amiga Resampler but have Amiga Frequency Limits disabled - OpenMPT Issue Tracker

ID	Project	Category	View Status	Date Submitted	Last Update

0001830	OpenMPT	General	public	2024-10-16 03:06	2024-11-10 15:26

Reporter	Wibi	Assigned To	Saga Musix
Priority	normal	Severity	minor	Reproducibility	always
Status	resolved	Resolution	fixed
Platform	x64	OS	Windows	OS Version	10
Product Version	OpenMPT 1.31.10.00 / libopenmpt 0.7.10 (upgrade first)
Target Version	OpenMPT 1.32 / libopenmpt 0.8 (goals)	Fixed in Version	OpenMPT 1.32 / libopenmpt 0.8 (goals)

Summary	0001830: If "Use Amiga resampler for Amiga modules" is set, new .MODs use Amiga Resampler but have Amiga Frequency Limits disabled
Description	Per https://forum.openmpt.org/index.php?msg=49821 , the Amiga resampler is only meant to work with a limited frequency range, and anything else produces inconsistent results and should not be expected to remain the same in future versions or different programs. However, if "Use Amiga resampler for Amiga modules" is enabled in View->Setup->Mixer, then the default settings for a new .MOD file have the resampling set to Amiga Resampler, but have Amiga Frequency Limits disabled in the song properties. This is a bad default, as every time you make a new .MOD, you have to open the song properties and enable Amiga Frequency Limits before doing anything else if you want to ensure the sound remains consistent. (Suppose you carelessly put a Portamento Up that, unbeknownst to you, ends up too high; if you didn't think to manually enable Amiga Frequency Limits, the note you hear when you play back your song now in OpenMPT will be different to the note you hear when playing it back later with foo_openmpt54 or pt2-clone.) When "Use Amiga resampler for Amiga modules" is not enabled, then new .MOD files default to Sinc + LP resampling instead, so Amiga Frequency Limits being off by default is understandable in that case. Now, maybe this is really a user error because I click "New->MOD" instead of always opening a template with Amiga Frequency Limits enabled, or because I'm not careful enough while making songs to avoid going outside the Amiga limits in the first place, but having Amiga Frequency Limits be enabled by default when "Use Amiga resampler for Amiga modules" is enabled (and new .MOD files always count as "Amiga modules") seems like a sensible change in any case.
Steps To Reproduce	Open the setup window, then go to Mixer. In the "Resampling" section, make sure "Use Amiga resampler for Amiga modules" is on. Click File, hover over New, then click MOD. Observe that the default resampler is Amiga Resampler. Open the song properties and observe that Amiga Frequency Limits is disabled.
Tags	No tags attached.

Has the bug occurred in previous versions?	Yes
Tested code revision (in case you know it)

Wibi 2024-10-16 03:09 reporter ~0006095	Wasn't sure whether to tag this "Accessibility" or "User interface" since it is technically circumventable but inconvenient.

Saga Musix 2024-10-16 20:30 administrator ~0006096	Accessibility refers to issues with screen readers and other assistive technology so that's the incorrect category. I'm aware of this problem, and it's a bit of a chicken-and-egg problem amplified by the fact that none of these settings can be stored in a MOD file. However, the example you mention has nothing to do with the Amiga resampler: No matter if the Amiga resampler is active or not, OpenMPT will not assume Amiga frequency limits when creating a new MOD (because you may, in fact, want to create a new module for playback on PC and not care about those limits). You can always enter a pitch slide that goes too high or too low, and reopen the file and if no notes outside of the C-4...B-6 range are found, OpenMPT will always assume Amiga frequency limits - completely independent of whether the Amiga resampler is enabled or not. I guess the core question here is actually more along the lines of how we can make the choice of writing modules conforming or not confirming to Amiga limits easier to the user so it's not hidden two dialogs deep. Maybe a checkbox or "playback style" dropdown on the General tab which automatically configures a couple of compatibility flags. This would also potentially allow for enforcing FT2-like MOD playback, which is something people occasionally ask for.

Saga Musix 2024-11-10 15:26 administrator ~0006165	Okay, I think I found a good way to address this: As of r22141, there are now two options in the File -> New menu, and also in the selection for the default module format: MOD (Amiga) and MOD (PC). The two options do pretty much what it says on the tin: MOD (Amiga) creates a 4-channel module, enables all ProTracker quirks and the Amiga resampler (if enabled by the user). MOD (PC) creates an 8-channel module, disables ProTracker quirks, allows a great octave range and disables the Amiga resampler. Of course this cannot influence what happens when the file is re-opened, but at least it allows for a clean start in either of the two format variants.

Date Modified	Username	Field	Change
2024-10-16 03:06	Wibi	New Issue
2024-10-16 03:08	Wibi	Description Updated
2024-10-16 03:08	Wibi	Description Updated
2024-10-16 03:09	Wibi	Note Added: 0006095
2024-10-16 20:26	Saga Musix	Category	Accessibility => General
2024-10-16 20:30	Saga Musix	Note Added: 0006096
2024-11-10 15:24	Saga Musix	Assigned To	=> Saga Musix
2024-11-10 15:24	Saga Musix	Status	new => assigned
2024-11-10 15:26	Saga Musix	Note Added: 0006165
2024-11-10 15:26	Saga Musix	Status	assigned => resolved
2024-11-10 15:26	Saga Musix	Resolution	open => fixed
2024-11-10 15:26	Saga Musix	Fixed in Version	=> OpenMPT 1.32 / libopenmpt 0.8 (goals)
2024-11-10 15:26	Saga Musix	Target Version	=> OpenMPT 1.32 / libopenmpt 0.8 (goals)