Enable support for libsoxr

[Lastique]

I'd like to ask to enable support for libsoxr-based resamplers in the official Ubuntu packages for pulseaudio. The upstream already supports libsoxr and automatically detects its availability, so the only change really needed is to add the build dependency to debian/control.

The resamplers based in libsoxr offer better quality and better performace while introducing more delay compared to the speex resamplers that are used by default. The resamplers are documented in the man pages of pulseaudio in Ubuntu 16.04 but unfortunately are not enabled at build time ('pulseaudio --dump-resample-methods' doesn't list them). I've built local packages with libsoxr and verified that the resampler works as expected.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Amr Ibrahim (amribrahim1987)]

I support building with libsoxr.

[Daniel van Vugt (vanvugt)]

As I understand it, pulseaudio is in "main" and so is only allowed to depend on other packages in "main". soxr on the other hand is in "universe", see:
https://launchpad.net/ubuntu/+source/libsoxr

So you may have to work through the process of getting libsoxr moved into main before we can update pulseaudio to explicitly depend on it:
https://wiki.ubuntu.com/MainInclusionProcess

[Lastique (andysem)]

I've created a MIR ticket for libsoxr: https://bugs.launchpad.net/ubuntu/+source/libsoxr/+bug/1702558

[Neo (rdstmc)]

Still not included in 18.04 delivery ...

[Daniel van Vugt (vanvugt)]

That's mostly because fixing bug 1702558 is a prerequisite.

[賴家亨 (laichiaheng)]

It is 2018-10-11, and it hasn't been done since 2016-04-25

[Daniel van Vugt (vanvugt)]

The required change to libsoxr is now in 18.10 (and only in 18.10). However 18.10 is about to be released so it's too late to change pulseaudio there. We would be aiming for 19.04 and later now. Please give me a reminder again in November if no further progress has been made by then.

[Daniel van Vugt (vanvugt)]

Good news: Comment #8 is wrong.

I forgot that I had already released a new PulseAudio (v12.x) into Ubuntu 18.10 with libsoxr support enabled. So the fix is already in Ubuntu 18.10.

[Lastique (andysem)]

Yay, finally! Thank you Daniel.

[Neo (rdstmc)]

Hi,
Thanks.
I test it and I feel that sound is better with this re-sampler, as well lower on CPU.
Regards

[Rijnhard Hessel (rijnhard)]

Is it possible to get this backported to 18.04?

[Daniel van Vugt (vanvugt)]

It's probably possible, but is not a priority. And probably difficult to justify any enhancement request like this being backported to a stable release. If anyone would like to try then go ahead:

https://wiki.ubuntu.com/StableReleaseUpdates