Updated: February 25, 2013
As you already know, Steam requires the Flash Player plugin to be installed on your Linux box in order to play videos, which are encoded as Flash. Moreover, Steam requires the 32-bit version of the plugin for you to be able to watch the movies. And if you're running a 64-bit version of Linux, you will encounter a problem. We have discussed and resolved this problem in my first tutorial on this subject, using manual downloads from the Adobe site.
Several people emailed me asking for additional methods, possible audio problems and how to work around the fact you must manually manage the plugin, which can be considered a hassle and maybe even a security risk. Not to worry, in this guide, I will provide answers for all these questions.
You can also do this. Instead of doing manual downloads, you can tell the Ubuntu Software Center, or its command-line counterpart, to download the 32-bit version. Do not that this will uninstall your 64-bit version of the plugin. This is done by running the apt-get command with the i386 identifier, like this:
sudo apt-get install adobe-flashplugin:i386
And that's it. Your system will have the 32-bit version of Flash; and this means your Web browsers will also be using it. If you do not mind, then this is all you need to have full Steam support with automatic updates, as well as resolve possible audio problems.
However, you might not want this solution. You do want to keep the native 64-bit version of the plugin and make Steam only use the 32-bit version. In that regard, you will have to resort to manual updates. But can you make them automatic? The answer is yes. You can create a wrapper for the system updates script.
This is true for systems managed by apt-get, including Ubuntu, Mint and family. For Fuduntu, which is based on Fedora, although an earlier version, and which uses yum, you can specify an alternate installation path, which is really dandy.
So your script might look something like this:
apt-get -y dist-upgrade
apt-get -y install adobe-flashplugin:i386
cp /usr/lib/flashplugin-installer/libflashplayer.so /usr/lib/firefox/plugins
apt-get -y install flashplugin-installer
Do note the fourth command - in order to know where the package manager places the 32-bit version of the Flash Player plugin, please run updatedb and locate commands. Or you can perform a live search with find, but this will be slower. You can use different target directories, including the Steam folder inside your home, which does not require sudo or root. The Steam default directory is: ~/.local/share/Steam/ubuntu12_32/plugins.
Now, notice the first screenshot - the 64-bit version in placed in the flashplugin-installer directory. It's a bit confusing, because both objects have identical names, and you will need to use the file command to differentiate between them. Then, in the second image, you can see that after the installation of the 32-bit version, the plugin will be placed in the adobe-flashplugin directory.
You can copy the plugin anywhere you want, and then create a symbolic link to the Firefox plugin directory:
sudo ln -sf <location of your file> /usr/lib/firefox/plugins/<file placeholder>
Once again, you can use other locations, like /usr/lib/firefox-addons/plugins,
/usr/lib/mozilla/plugins, as well as directory inside your home, where you do not
need to have sudo or root permissions to use and manipulate the files.
This is an alternative method without messing up with system installs. You pull the tar file from Adobe using wget command, extract it somewhere, then copy the libflashplayer.so shared object into the Firefox plugins directory or anywhere you want, with the relevant symbolic link. In both cases, this script and the previous one, you will have to run it as root or sudo, and make it executable.
apt-get -y dist-upgrade
wget -O - "<adobe site link> | tar xz -C <preferred location> libflashplayer.so
Since the Adobe site location might change now and then, you might want to pass the exact URL for the tar archive as an input parameter to your script. This way you can keep maintaining both the 32-bit and 64-bit versions together.
Anyhow, Reddit guys have discussed this in a thread that links to my first Flash tutorial, and provided several alternative automated solutions. There's even a script hosted on Github. However, the script hardcodes a very specific version of Flash Player, so you will need to adapt it, by passing an input parameter. Moreover, the script does not address the overall system upgrade, which you can resolve using my method by running a system-wide update first. There's also the matter of input validation, checking for existence of directories before creating them and suchlike, but it's a nice effort, nonetheless.
If you are facing possible audio playback problems with the Flash Player in Steam, there are several possible workarounds and fixes you might want to check. The first and most obvious one is, do run all of the above and see what resolves it. Placing the 32-bit version of the plugin elsewhere, or obtaining the software through the package manager might get you around your trouble.
Moreover, please check the file permissions for the plugin. It should be readable to non-root users, so the file permissions need to be 644. And that is all that comes to mind right now.
You might also be interested in the following articles:
Steam Linux official version install guide
Steam Linux first impressions
Team Fortress review
Linux Flash Player setup
Flash Player privacy settings
Flash Player protected mode thingie
Google Chrome Flash issues
This is a fairly lengthy tutorial, but it comes with a lot of goodies. In addition to the obvious Linux lessons on how to manage packages, search for files and write scripts, it teaches us a handsome deal on the Steam internals, from a completely new angle. Now we have the full control of the software and we can do as we please.
Specifically, regarding the Flash Player, which is the reason why you came here, you have several automated and manual methods for managing the plugin, while remaining safe and whatnot. You can create wrapper scripts that install the desired version, or even pull the tar archive from the official site. Either method allows you to stay current any time you update your system, which is quite convenient. We also have a short discussion on audio problems. All in all, enough for one article, and now it's time for you to test all this and play.