Hi,
I noticed this issue and am currently preparing release 1.4.6 of haikuwebkit to fix it. I don't know if the build will be done before I leave for BeGeistert, however.
There is a recipe for the latest version of ffmpeg which works with gcc4, but gcc2 will need to stay at 0.10 for now. I did more testing with 0.11 and there are still problems with h263 and h264 decoding. I tried disabling various things (MMX, SSE, use of asm code, etc) but it still crashes. Later versions are even harder to get to compile with gcc2.
There is no problem with updating the gcc4 version of ffmpeg, but the media add-on must be made to work with either version (or maybe we need an ffmpeg_legacy one for gcc2 and an ffmpeg one for gcc4). This allows the gcc4 world to move on but doesn't solve our issue with legacy apps.
