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

Submitted by Alain Kalker

Link to original bug (#742271)

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