xrdp/sesman/chansrv/pulse

The latest version of this document can be found at wiki.

• https://github.com/neutrinolabs/xrdp/wiki/How-to-set-up-audio-redirection

Overview

xrdp supports audio redirection using PulseAudio, which is a sound system for POSIX operating systems. Server to client redirection is compliant to Remote Desktop Procol standard [MS-RDPEA] but client to server redirection implementation is proprietary. Accordingly, server to client redirection is available with many of RDP clients including Microsoft client but client to server redirection requires NeutrinoRDP client, not available with other clients.

Here is how to build pulseaudio modules for your distro, so you can have audio support through xrdp.

Prerequisites

Prepare xrdp source in your home directory. Of course, you can choose another directory.

cd ~
git clone https://github.com/neutrinolabs/xrdp.git

In this instruction, pulseaudio version is 10.0. Replace the version number in this instruction if your environment has different versions. You can find out your pulseaudio version executing the following command:

pulseaudio --version

How to build

Debian 9 / Ubuntu

This instruction also should be applicable to Ubuntu family.

Prerequisites

Some build tools and package development tools are required. Make sure install the tools.

apt install build-essential dpkg-dev

Prepare & build

Install pulseaudio and requisite packages to build pulseaudio.

apt install pulseaudio
apt build-dep pulseaudio

Fetch the pulseaudio source . You'll see pulseaudio-10.0 directory in your current directory.

apt source pulseaudio

Enter into the directory and build the pulseaudio package.

cd pulseaudio-10.0
dpkg-buildpackage -rfakeroot -uc -b

Enter into pulse directory in xrdp source.

cd ~/xrdp/sesman/chansrv/pulse
nano Makefile

Edit the Makefile. Replace /tmp/pulseaudio-10.0 with your pulseaudio source directory.

diff --git a/sesman/chansrv/pulse/Makefile b/sesman/chansrv/pulse/Makefile
index 74977221..395ef0a0 100644
--- a/sesman/chansrv/pulse/Makefile
+++ b/sesman/chansrv/pulse/Makefile
@@ -3,7 +3,7 @@
 #

 # change this to your pulseaudio source directory
-PULSE_DIR = /tmp/pulseaudio-10.0
+PULSE_DIR = /home/debian/pulseaudio-10.0
 CFLAGS    = -Wall -O2 -I$(PULSE_DIR) -I$(PULSE_DIR)/src -DHAVE_CONFIG_H -fPIC

 all: module-xrdp-sink.so module-xrdp-source.so

Finally, let's make. You'll have two .so files module-xrdp-sink.so and module-xrdp-source.so.

make

Other distro

First off, find out your pulseaudio version using pulseaudio --version command. Download the tarball of the pulseaudio version that you have.

• https://freedesktop.org/software/pulseaudio/releases/

After downloading the tarball, extact the tarball and cd into the source directory, then run ./configure.

wget https://freedesktop.org/software/pulseaudio/releases/pulseaudio-10.0.tar.xz
tar xf pulseaudio-10.0.tar.gz
cd pulseaudio-10.0
./configure

If additional packages are required to run ./configure, install requisite packages depending on your environment.

Next, enter into pulse directory in xrdp source and replace /tmp/pulseaudio-10.0 in Makefile with your pulseaudio source directory.

cd ~/xrdp/sesman/chansrv/pulse
nano Makefile

Finally, let's make. You'll have two .so files module-xrdp-sink.so and module-xrdp-source.so.

make

Install

Install process is not distro specific except for install destination. Install built two .so files into the pulseaudio modules directory. Typically, /usr/lib/pulse-10.0/modules for Debian, /usr/lib64/pulse-10.0/modules for CentOS 7. Other distro might have different path. Find out the right path for your distro.

Look into the directory with ls command. You'll see lots of module-*.so files. There's the place!

cd ~/xrdp/sesman/chansrv/pulse
for f in *.so; do install -s -m 644 $f /usr/lib/pulse-10.0/modules; done

This command is equivalent to following:

install -s -m 644 module-xrdp-sink.so /usr/lib/pulse-10.0/modules
install -s -m 644 module-xrdp-source.so /usr/lib/pulse-10.0/modules

Well done! Pulseaudio modules should be properly built and installed.

See if it works

To see if it works, run pavumeter in the xrdp session. Playback any YouTube video in Firefox. You'll see "Showing signal levels of xrdp sink" and volume meter moving.