Fade out: track silent until the end #2978

Is there an existing issue for this?

• I have searched the existing issues

I have read the contribution rules

• I have read CONTRIBUTING.md and, if any AI agent helped draft this issue, AGENTS.md.

AI authorship

AI-assisted (disclosure block included as described in AGENTS.md)

Current Behavior

• beat with fade out (or volume swell)
• after it: track silent until the end of the song
• changeTrackVolume(): no effect (volume × 0 = 0)

Expected Behavior

• fade out = only its beat
• next notes: normal track volume (like Guitar Pro)

Steps To Reproduce

1. Track with: fade in on a beat, fade out on a later beat, more notes after
2. Load the file
3. Play the track (solo)
4. Notes after the fade out: no sound

Link to jsFiddle, CodePen, Project

No response

Version and Environment

[AlphaTab][VersionInfo] alphaTab 1.8.4
[AlphaTab][VersionInfo] commit: 022a45c8e42370f9e12e68949d11eada370da83d
[AlphaTab][VersionInfo] build date: 2026-07-05T14:46:18.224Z
[AlphaTab][VersionInfo] High DPI: 1
[AlphaTab][VersionInfo] Platform: BrowserModule
[AlphaTab][VersionInfo] WebPack: false
[AlphaTab][VersionInfo] Vite: false
[AlphaTab][VersionInfo] Browser: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) HeadlessChrome/156.0.8078.4 Safari/537.36
[AlphaTab][VersionInfo] Window Size: 1400x1000
[AlphaTab][VersionInfo] Screen Size: 1400x1000
Also on: Chrome Android (same result) and Firefox Android (same result)
Same code in: 1.9.0-alpha.1963

Platform

Web

Anything else?

Cause:

• MidiFileGenerator._generateFade
• fade out → VolumeCoarse down to 0 (primary + secondary channel)
• no reset after

Fix idea:

• fade out + volume swell: add VolumeCoarse = track volume at beatStart + beatDuration
• track volume = playbackInfo.volume, or current volume automation if any