Prolonged Piano pedal causes crackling / distortion during playback

• Oct 27, 2020 - 22:39
Reported version
3.5
Type
Performance
Frequency
Once
Severity
S3 - Major
Reproducibility
Always
Status
active
Regression
No
Workaround
No
Project

I apologize if this has been reported; the closest I've been able to find on the forums are general playback issues on MacOS, nothing as specific as what I'm experiencing.

Steps to reproduce:
1) Open a new score for piano (A single staff will do, but the problem occurs more quickly with more notes/staves).
2) Populate ~30 measures of one or both staves with eighth-notes (note variety does not matter). Quarter notes will also cause the problem, albeit more slowly, and adding notes (quarter, half, whole) to the other staff will make it happen more quickly.
3) Add a pedal line and extend it to include all of the measures.
(only needs to be on one staff, regardless if both are populated).
4) Start playback from the beginning.

Expected behaviour: Musescore synthesizes score as written with no issues

Actual behaviour: Within ~12 measures (@120BPM) sputtering and distortion occur, and playback slows slightly. Issue is exacerbated by panning around the score during playback.

Discussion: Reducing the BPM reduces the problem, with issues reducing down at around 60-80, and disappearing almost entirely at around 30. Increasing BPM seems to cause it to occur more quickly, but only marginally. Stopping and starting mid-score resets the player and issues disappear entirely, only to begin again within 8-12 measures (@120BPM). On MacOS, the sputtering disappears when you swipe over to another workspace while the playback is occurring, and begins immediately again when you swipe back to Musescore. It also reduces slightly –but doesn't disappear– when Musescore loses focus but you stay on the same workspace. On occasion, bringing up the Play panel itself causes a moment of distortion as well.

OS: macOS 10.15, Arch.: x86_64, MuseScore version (64-bit): 3.5.2.312126096, revision: 465e7b6

I've also tested in the following versions of Musescore:

2.3.1 (barely reproducible, only achieved by massively speeding up BPM)
3.0.0.20139 ( barely reproducible, only achieved by massively speeding up BPM)
3.0.1.20442 ( barely reproducible, only achieved by massively speeding up BPM)
3.0.2.21004 (reproducible, but the effect is greatly reduced. Exacerbated by speeding up BPM)
3.0.3.21091 (reproducible, but the effect is greatly reduced. Exacerbated by speeding up BPM)
3.0.4.21119 (reproducible, but the effect is greatly reduced. Exacerbated by speeding up BPM)
3.0.5.21966 (completely reproducible)
3.1.0.22487 (completely reproducible)
3.4.2 (completely reproducible)

Attachment Size
TestScore_playbackBug.mscz 15.37 KB