Bug#799176: libspeexdsp1: Severe clipping of audio when libspeex resampler is used by ALSA or pulse audio

[Erik]

Package: libspeexdsp1
Version: 1.2~rc1.2-1
Severity: grave
Tags: fixed-upstream
Justification: causes non-serious data loss

On my armhf-systems (Raspberry Pi 2), the resampler library in libspeexdsp1 is introducing extreme 
distortion / clipping unless the input stream is strongly attenuated.

I've done some additional tests confirming that:
 - The bug also exists upstream
 - The bug is corrected in latest upstream (upstream change log mentions correcting a clipping/overflow error)

Additional tests:
- Rebuild of libspeexdsp.so.1.5.0 - Clipping/Distortion
- Rebuild of libspeexdsp.so.1.5.0, without debian patches in the resampler - Clipping/Distortion
- Rebuild of libspeexdsp.so.1.5.0, but resampler.c updated to match latest speex release - Clean audio!!

Some discussion also here:
https://discuss.mopidy.com/t/severe-clipping-of-audio-when-using-alsa/878

Note1: This is my first time writing a debian bug report. Please change fields as necessary
Note2: The libspeexdsp is default for both ALSA and pulse audio, this issue thus has a big impact on overall 
useability of the system for any multimedia or audio related tasks.

-- System Information:
Debian Release: 8.2
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: armhf

Kernel: Linux 4.1.3-2-osmc (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)