About one year ago, Sam Hocevar posted some results on tests with his fuzzing tool zzuf, which showed a large number of crashes in various applications, especially multimedia apps.
Crash bugs on invalid input very often lead to security issues, thus this should be taken seriously.

Now, I took the freedom to have a look how many of the issues found back then were fixed. I used the most current versions in gentoo linux (testing/~x86-system), which tend to be quite up-to-date. I also cross-checked the crashes for other apps, as they often use the same or similar code.
Seems only vlc devs did their homework (Sam Hocevar is part of the vlc team). Interesting enough, even firefox seems to have a gif-crasher since a year.

gstreamer crash by lol-ffplay.mpg lol-gstreamer.m2v lol-mplayer.m2v lol-mplayer.mpg lol-vlc.m2v lol-vlc.mpg
endless loop by lol-ffplay.m2v lol-xine.mpg

mplayer hang by lol-mplayer.wmv,
crash by lol-ffplay.flac lol-mplayer.aac lol-mplayer.mpg lol-mplayer.ogg lol-ogg123.flac lol-vlc.aac lol-xine.aac

xine crash by lol-mplayer.wmv lol-ffplay.m2v lol-ffplay.ogg lol-ffplay.wmv lol-gstreamer.avi lol-ogg123.flac lol-vlc.aac lol-xine.mpg

firefox crash by lol-firefox.gif

Thanks to Kostya, ffmpeg now supports the VC-1 codec, which is also used in Microsofts WMV9-format.

In the past, for Linux-users it was only possible to play those videos with win32codecs, which use proprietary windows-dlls and don't work on non-x86-platforms. With this improvement, one of the most common multimedia-formats unsupported by free software can now be played with all major free players (as ffmpeg is used by vlc, xine, mplayer, totem and many others).

Congrats to the ffmpeg-guys. The easiest way to get stuff playing is getting mplayer from svn (I used the mplayer-svn-ebuild from this Multimedia Overlay with some small modifications).

(via Breaking Eggs and making Omelettes)