SCALE 8x: Gnash, the free Flash player

Rob Savoye of Open Media Now! (OMN) gave an overview of the work OMN has been doing on making free versions of various Adobe products available for use on free platforms. He concentrated mostly on Gnash, the GNU Flash player, but also touched on the Cygnal media server, and the Ming ActionScript compiler. Gnash has been one of the Free Software Foundation's priority projects for several years, which has resulted in more developers as well as raising the profile of the project.

Flash is important because it is used for web site navigation, video web sites, and, perhaps most importantly to Savoye, for educational applications. There are an enormous number of educational programs written in Flash and free software couldn't support running them. Because he is a "fanatic" about freedom, Savoye never installed the Flash plugin, which made him and others like him into "second-class citizens on the internet".

There are a number of reasons to implement a free replacement for the Flash plugin, beyond just being able to view YouTube. The Adobe plugin is full of security problems and doesn't integrate well with Linux. There is no 64-bit support and it is essentially only available for the x86 architecture. In addition, some day archeologists may want to play Flash content and the Adobe plugin may have long faded away.

Though he likes working on Gnash, Savoye is no fan of Flash. In answer to a question at the end of his talk, he said: "I hope Flash falls over dead", and that is something he is starting to see happen. In the meantime, though, he recommends against using Flash for web sites, and to use HTML 5 instead. He also suggested encouraging sites that do use Flash to at least test against Gnash so that the site will work for those on other platforms.

Some history

Gnash was started in 2004 because Savoye wanted a user interface for his stereo system. That was Gnash's first platform and he still runs his stereo that way today. In 2005, John Gilmore asked him to turn it into a browser plugin, and he delivered plugins for Firefox and Konqueror in 2006. YouTube support came in 2007.

The development community that formed after the FSF high-priority rating decided that it "would be really nice to have funding", so they started OMN, which has been funded by Bob Young, Mark Shuttleworth, John Gilmore, and others. They have continued to reverse-engineer the Adobe formats and protocols, while also getting Gnash running on "all sorts of weird hardware".

Weird devices

He put up a slide with a picture of Gnash running on various embedded devices: OLPC, Sharp Zaurus, Pepper Pad, Classmate PC, OpenMoko, Playstation 3, etc. He noted that Adobe Flash didn't run on any of them. The OLPC isn't able to redistribute the Adobe Flash player, so they turned to Gnash. As part of getting better Gnash performance on the OLPC, Savoye wrote some GCC and Glibc optimizations for the Geode processor.

Gnash is a clean-room re-implementation of Flash, which means that none of its developers have ever used Adobe's Flash. The EULA that comes with the Flash plugin restricts users from being able to create a competing Flash implementation. So, all of the development was done using publicly available documentation, which is important because if it wasn't done legally, the distributions won't include it. Though they were worried about legal action in the first few years, Adobe recently announced that Gnash is a "legal re-implementation" of Flash.

Gnash features

Gnash can be run either standalone or as a browser plugin for Firefox and Konqueror, with Safari support coming soon. It got OpenGL support for desktop graphics rendering before Adobe did, and has added Anti-Grain Geometry (AGG) support for embedded framebuffer-only devices.

One of the areas that Gnash has concentrated on is security. Adobe's Flash is "really insecure", Savoye said, and if you use a banking site with a Flash interface, you should "be worried". It also has better privacy protection because, by default, Gnash deletes all Flash cookies whenever it exits.

Gnash allows users to extend ActionScript with their own code, or by writing a wrapper around an existing development library. It also supports patent-free codecs, he said, in addition to the standard proprietary ones.

Compatibility, portability, and performance

Gnash can read SWF ("Shockwave Flash") version 9 and earlier files, but primarily supports SWF version 8. Version 9 is under active development, though. Roughly 80% of the ActionScript v2.0 library has been implemented, and the rest of it he has "never seen in the real world". SWF version 10 support is underway as well, but "it's pretty nasty". The ActionScript v3.0 library can reuse many of the v2.0 classes, but version 10 requires support for all of the previous versions, each running in different virtual machines, so there is a lot of work to be done.

Savoye said that they rarely port Gnash any more as it is just a matter of reconfiguring and recompiling it for new hardware. It will run on any system that is POSIX conforming and has ANSI C++ support. It also supports some non-POSIX environments; he noted that he had never heard of Haiku, which is a BeOS clone, but saw it and Gnash running on it down on the SCALE Expo floor. Gnash supports many different architectures, with big or little-endian processors of 32 or 64-bits. It also supports many different GUIs and desktop environments, as well as several back-end renderers (AGG, OpenGL, and Cairo).

For performance, Gnash can use the X11 Xvideo extension for high-resolution full-screen video. Xvideo also reduces the memory footprint. Support is also being added for hardware video decoding on Intel, ATI, and NVIDIA hardware using libvaapi.

It is written in C++ and uses the Boost libraries. Gnash uses either Gstreamer or FFmpeg for media handling. He noted that most distributions use Gstreamer to avoid the codec issues, but that FFmpeg is much faster and Gstreamer can use that as well. For HTTP and HTTPS, Gnash uses libcurl. It supports either GNOME or KDE desktops, or no desktop at all, he said.

Much like Perl or Python, Gnash can wrap any development library so that they can be used from ActionScript. Currently, there are extensions available for things like direct filesystem access, MySQL, GTK2, D-Bus, and so on. The extensions are added directly into ActionScript and can be accessed just like any other ActionScript class.

Current focus

The Gnash team is currently concentrating on supporting SWF 9 and 10, as well as ActionScript 3. "Chasing Adobe" is what they will be doing "for the rest of our lives, at least in this project", Savoye said. There is also ongoing work on the RTMP protocols for Gnash and Cygnal, getting better performance from low-end hardware, and better support for hardware acceleration. They are also working on Flash-based video conferencing so that there will be free solutions in that area.

There is also a lot of work going into Cygnal because there isn't a good rich media server in the free software world. Various groupware and video conferencing applications are written in Flash, but they need server-side support. By implementing a free media server, they can concentrate on better security and privacy than Adobe or another proprietary company is likely to provide, he said.

How to help

Savoye was not shy about suggesting "free beer" as one of the best aids for helping Gnash development, but there are others as well. "Good bug reports" are crucial. The usual suspects for a free software projects: translations, documentation, web site development and maintenance, build farm help, and so forth, are areas where people could help out. Also, donations are always appreciated, he said.

While it is sometimes galling to think that the "open web" requires some way to play Flash content, it is an unfortunate reality today. In six years or so, Gnash has come a long way towards replacing Adobe's closed plugin on x86 desktops, and is the only solution for many other devices and architectures. When one considers that Savoye and the rest of the Gnash team have never actually installed Flash for themselves, that feat is even more amazing. If the adoption of the newer versions of Flash can be slowed—or stopped—there is even hope that Gnash can catch up and we can get rid of one more non-free blob on our desktops.