Ubuntu – Flash Breaking Pulseaudio

flashmpdpulseaudio

Since posting this question, it has been revealed that the problem was with mpd — not Flash. Here is the question I posted in an attempt to find a fix.

Every time a Flash object with sound (such as a video) loads in my browser (Chromium or Firefox), it seems to break Pulseaudio. Further Flash content will play just fine, but other software, such as MPD, will not be heard. I can reset this problem by ensuring that no instance of Flash are running in my browser and running pulseaudio -k, but the problem just comes back as soon as another Flash object initialises.

In being a little more specific, if I have sound playing (such as with MPD) and load a Flash object, sound continues to play but Flash doesn't output any sound. If I stop playing sound and then load the Flash object, Flash gets sound and seemingly takes control of Pulseaudio until pulseaudio -k.

May or may not be related: When Flash doesn't get to output sound it tends to crash Chromium. I can't say if this is only when Flash gets control of Pulseaudio or not, as it doesn't always crash.

I'm running the latest version of Flash, just downloaded and installed from Adobe's site using their 32-bit deb. I have tried flashplugin-installer but the problem is the same. Running Ubuntu 10.10.

Any idea how I can fix this, or why it's happening? Does it matter that I'm running mpd as root?

Best Answer

The problem to solve is to get the Music player Daemon to play properly with pulseaudio

You can check that your copy of MPD includes PulseAudio support by running mpd --version and making sure "pulse" is in the list of supported outputs. this is the case on Ubuntu now so it is just a matter of getting mpd to work well with pulseAudio.

Related Solutions

Ubuntu – mpd conflicting with other applications — taking control of pulse

I had this problem when I first started using mpd, but it was quite some time ago, so I can't exactly remember what I did to fix it!

Do you have PulseAudio preferences installed? I found this tip on a forum: sudo apt-get install paprefs

Then open PulseAudio prefrences from the menu: System->Preferences->PulseAudio Preferences Click the Network Server tab, then check the "Enable network access to local sound devices" box, and finally check the "Don't require authentication" box. After that, restart mpd: sudo /etc/init.d/mpd restart

However... I just realized that mpd works fine for me and I don't have "network access to local sound devices" enabled.

I think you might be right about needing to run mpd as the current user, which is what I'm doing. (I have no clue as to why this is though!)

A simple guide to setting up mpd to be run as a user can be found here: http://gmpc.wikia.com/wiki/MPD_INSTALL_USER_SERVICE_UBUNTU

To sum things up, since you already have mpd installed:

1.) Stop it: sudo update-rc.d mpd disable

2.) Copy your mpdconf to your home directiory (as .mpdconf), and change the following entries to places where your user can access and write to:

music_directory
playlist_directory
db_file
log_file
error_file
pid_file
state_file

The page I'm taking this from suggests just creating a .mpd folder in your home directory for this stuff, save for your actual music directory.

3.) Comment out the user line in .mpdconf: #user "mpd"

4.) Now you can run mpd and update the database.

5.) To make mpd start up automatically as a user when logging in, go to Startup Applications and add an entry for mpd, then create an autostart file in ~/.config/autostart/.

[Desktop Entry]
Type=Application
Exec=mpd
Hidden=false
NoDisplay=false
Terminal=false
X-GNOME-Autostart-enabled=true
Name[en_US]=Music Player Daemon
Name=Music Player Daemon
Comment[en_US]=plays the music
Comment=plays the music

There are probably downsides to running as a user, so maybe this won't suit your needs.

Ubuntu – Flash in browsers does not play sound accurately using Pulse network audio

Preface

I was able to replicate Dave's issue in experiments, and they lead me to believe that Flash is somehow sending the sound to PulseAudio in such a way that it creates a lot of network traffic (think lots of tiny packets, not bandwidth); this overwhelms the network "tunnel" PulseAudio has created, i.e. you have

Youtube => [PA-client => network => PA-server] => speakers

I could solve the issue by putting both the client and server on their own virtual network, giving them effectively infinitely fast connectivity (10 Gbits/sec) between them; obviously, that doesn't work for real-world networks :)

So, a bit of googling and this post and this one gave me the idea of dropping the tunnel (middleman, as Dave aptly put it), and having the client talk directly to the server, i.e.

Youtube => network => PA-server => speakers

And that worked for me; Flash videos/sound play flawlessly.

Let's try it!

This assumes your client-server are on a local network (router, etc.)

Preliminary: On the client machine, if you have an existing setup, open paprefs and uncheck everything; then kill PulseAudio to be sure.
On the server machine (i.e., the one with the speakers), start PA Preferences (paprefs) and set it up as follows:
- Then close it, and kill PulseAudio in a terminal as shown, wait, and check that it is now listening on port 4713:
- If you don't see it, open paprefs again and check the remaining boxes in the Network Access and Network Server tabs (they don't hurt)
- Make sure you know the server's IP address - use ifconfig, etc. We'll use 192.168.0.4 in our example.
On the client machine, open a terminal, and test our direct connection first, with a speech sample WAV (replace 192.168... with your server IP!)
```
wget http://www.signalogic.com/melp/EngSamples/Orig/female.wav
paplay --server=192.168.0.4:4713 female.wav
```
- Abort with Ctrl-C if it works, it can get boring ;)

Now, close all running browser instances, and then start it (assuming Firefox here with the following syntax):

PULSE_SERVER=192.168.0.4:4713 firefox &

Replace 192... with the appropriate IP for your server!
In that Firefox instance, open up Youtube (or whichever Flash video site), and try playing videos back --- fingers crossed, it should work without stuttering/pausing!

Make it stick

If you want to make this fix apply to all programs instead of having to put PULSE_SERVER=192.168.0.4:4713 in front of every command, edit /etc/environment on the client and add PULSE_SERVER=192.168.0.4:4713 on a new line at the end of the file. Also add a line break at the end.

This will make all sound on the client go to the Pulseaudio server, so be sure that's what you want before making this edit to your /etc/environment file.

Reboot, and enjoy a smooooooth audio experience. ;)