REGRESSION: parameter loading undefined behaviour - Severely distorted sound on changing volume of stream in pulseaudio

Submitted by Alain Kalker

Description

Created attachment 293666
Arch linux build script for building orc from git

Using Arch Linux x86_64 with pulseaudio 5.0-1, orc 0.4.23-1, I'm getting severely distorted audio after I change the volume of a stream, even by just a little.

Steps to reproduce

$ pulseaudio -k
$ # restart pulseaudio if it doesn't start automatically on first use
$ man man | espeak # Generate some audio, varying dynamics.

In pavucontrol, move the volume slider for the espeak application stream just a little.

Actual result: severely distorted audio (almost like white noise, barely discernible speech from espeak).
Expected result: clear audio for reasonable volume settings.

The problem does not occur for orc 0.4.22 .

Building an Arch linux package of orc from git[1], I was able to bisect the problem to this first bad commit:

http://cgit.freedesktop.org/gstreamer/orc/commit/?id=a62eefc1dc716046d99aacec208cfdfe42dadb34

Suspecting a breaking ABI change (because of the added struct members), I rebuilt and reinstalled pulseaudio[2], but to no avail, sound remains distorted.

[1]: See attached PKGBUILD.orc-git
[2]: See attached PKGBUILD.pulseaudio

Attachment 293666, "Arch linux build script for building orc from git":
PKGBUILD.orc-git

Edited Nov 10, 2018 by Tim-Philipp Müller