MIDI Soundfont-based rendering behaviour with note off without sustain? \ VOGONS

MIDI Soundfont-based rendering behaviour with note off without sustain?

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First post, by superfury

Posted on 2020-09-14, 00:06

superfury Offline

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What is the MIDI ADSR(actually DAHDSR in the format) behaviour when a note is released and not held using the sustain pedal during any of the pre-sustain phases(delay,attack,hold,decay)? Does it jump immediately to release phase from the current level of attenuation? That's what UniPCemu is currently doing. Is that correct behaviour?

Author of the UniPCemu emulator.
UniPCemu Git repository
UniPCemu for Android, Windows, PSP, Vita and Switch on itch.io

Reply 1 of 1, by superfury

Posted on 2020-09-14, 01:24

superfury Offline

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Rank: l33t++
Posts: 5840
Joined: 2014-03-08, 11:25
Location: Netherlands

I notice some interesting behaviour with the AweROMGM.sf2 "slow strings" instrument(preset number 49). When it's sounding a note-on key, it has a strange behaviour. Somehow, the attack phase seems to weirdly start later(by the same time the attack phase is supposed to last)?

Thus it's always about half a second late compared to what Viena is giving me as the supposed output speed of the envelope? According to the soundfont, it should have a 0.594 second attack phase, but it sounds like the attack phase starts at that time, lasting for 0.594 seconds for some reason?
Forcing said variable to become 0(thus instantaneous attack) causes the sounds to match Viena's results?

Or could it be that the issue is a different matter altogether? Just the volume slope being incorrect somehow (wrong formula)?

Author of the UniPCemu emulator.
UniPCemu Git repository
UniPCemu for Android, Windows, PSP, Vita and Switch on itch.io

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