View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0001666||OpenMPT||Playback Compatibility||public||2023-02-14 17:57||2023-02-15 21:01|
|Reporter||mrbumpy409||Assigned To||Saga Musix|
|Platform||x86 / x64||OS||Wine||OS Version||(version plz)|
|Product Version||OpenMPT 1.30.10.00 / libopenmpt 0.6.8 (upgrade first)|
|Target Version||OpenMPT 1.31 / libopenmpt 0.7 (goals)||Fixed in Version||OpenMPT 1.31 / libopenmpt 0.7 (goals)|
|Summary||0001666: volume slide ramping too smooth in Interference demo soundtrack|
In the famous soundtrack for Sanity's Interference demo, Virgill uses the volume slide command to essentially create a sawtooth-wave amplitude LFO over the samples. On the Amiga, the return to full volume happens quickly, creating a percussive sound. In OpenMPT, however, this return to full volume is ramped, creating a notably softer effect.
You can download the MOD from here: https://modarchive.org/index.php?request=view_by_moduleid&query=68804
The issue takes place in pattern 30, all channels. Virgill is using the technique described in this video, starting at the 4-minute mark: https://www.youtube.com/watch?v=Sz6s0kP-nt4
I have attached audio of pattern 30 played in both OpenMPT and Amiga for comparison.
|Tags||No tags attached.|
|Has the bug occurred in previous versions?||yes|
|Tested code revision (in case you know it)|
audio files for comparison
Interference pattern 30.zip (397,058 bytes)
The same technique is used at the beginning of Fury Forest by Moby (https://modarchive.org/index.php?request=view_by_moduleid&query=40814). I have attached audio comparisons for this one as well. The effect on Amiga is once again much more percussive. IMO, OpenMPT should still have a tiny amount of ramping to avoid the clicks you hear here, but I would argue that OpenMPT's current amount of ramping in this context is too smooth.
Note that on-the-fly sample swapping needs to be enabled in compatibility settings for proper playback of this module.
Moby - Fury Forest audio comparison.zip (750,893 bytes)
Last edited: 2023-02-15 21:01
Indeed, when using instrument numbers + volume slides the volume was ramped over a whole tick. This didn't happen when instead using set volume + volume slide (a combination that's not possible in the MOD format but is for example possible in XM, S3M and IT). The behaviour has now been made consistent between those two possible ways of the gating effect. While it's a small change in code, it is a big change in practice affecting potentially many modules out there. Hence I'm not quite comfortable in backporting it to older OpenMPT or libopenmpt versions (yet), and will keep the fix from r18739 in the upcoming major update (OpenMPT 1.31) only.
|2023-02-14 17:57||mrbumpy409||New Issue|
|2023-02-14 17:59||mrbumpy409||Note Added: 0005553|
|2023-02-14 17:59||mrbumpy409||File Added: Interference pattern 30.zip|
|2023-02-14 18:20||mrbumpy409||Note Added: 0005554|
|2023-02-14 18:20||mrbumpy409||File Added: Moby - Fury Forest audio comparison.zip|
|2023-02-15 20:50||Saga Musix||Assigned To||=> Saga Musix|
|2023-02-15 20:50||Saga Musix||Status||new => assigned|
|2023-02-15 20:54||Saga Musix||Note Added: 0005555|
|2023-02-15 20:54||Saga Musix||Status||assigned => resolved|
|2023-02-15 20:54||Saga Musix||Resolution||open => fixed|
|2023-02-15 20:54||Saga Musix||Fixed in Version||=> OpenMPT 1.31 / libopenmpt 0.7 (goals)|
|2023-02-15 20:54||Saga Musix||Target Version||=> OpenMPT 1.31 / libopenmpt 0.7 (goals)|
|2023-02-15 21:01||Saga Musix||Note Edited: 0005555|