[Bug 20484] New: Audio distortion using Jack

http://bugs.winehq.org/show_bug.cgi?id=20484

Summary: Audio distortion using Jack
           Product: Wine
           Version: 1.0.0
          Platform: PC
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gdi32
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

When using Jack as the audio back end for wine low level but significant
distortion is heard and measurable on the output.

The level of distortion is sufficient to make wine jack unuseable for medium
quality audio applications (i.e. quality is rediced to equivelant of 32kbs -
mp3). This occurs on all signal levels and does not appear to be clipping.

This can be reproduced and identified most easily by recording the Jack output
with Audacity (also tested with other jack recording applications) and
comparing the spectrum of the original and recorded signals.

The spectrum indicates that the full bandwidth is present, but additional
frequency content has appeared. This also occurs when dithering is enabled in
jack.

Sounds like re-sampling aliasing issue - or perhaps an internal filter variable
scaling problem.