| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000524 | OpenMPT | General | public | 2014-05-07 17:21 | 2014-05-07 17:56 |
| Reporter | boot-sector-viruz | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | sometimes |
| Status | closed | Resolution | not fixable | ||
| Platform | x64 | OS | Windows | OS Version | 7 |
| Product Version | OpenMPT 1.23.03.* (old testing) | ||||
| Summary | 0000524: Pitch Shift distorting sample waveform | ||||
| Description | When using the pitch shift feature, strange things happen to the sample waveform. Most of times, the sample gets somewhat overdriven/distorted. However, the result is not always the same. Problem occurs in x32 and x64 alike. | ||||
| Steps To Reproduce | Open a module In case you cannot reproduce the problem with the first pitch shift, repeatedly pitch shift the sample. At some point, you should see what I mean. | ||||
| Tags | No tags attached. | ||||
| Has the bug occurred in previous versions? | Not that I know of.... | ||||
| Tested code revision (in case you know it) | r4042 | ||||
 |
If you need high quality pitch shifting, OpenMPT's built-in pitch shift isn't for you. It introduces artefacts, yes, and if you experience that the waveform is "drifting" (which can lead to distortion), you will need to high-pass the sample before performing the pitch-shift (DC offset seems to multiply very quickly as far as I can tell). I cannot and won't touch the pitch shifting code itself since it's provided through an external library (which is the same library as in previous versions). |
