gst-av is a GStreamer plug-in to provide support for libav (fork of
FFmpeg), it is similar to gst-ffmpeg, but without GStreamer politics,
which means all libav plugins are supported, even if there are native
GStreamer alternatives; VP8, MP3, Ogg, Vorbis, AAC, etc. and only the
important stuff for now: encoders and decoders.
In addition, it is much simpler (2654 vs 16575 LOC), has better
performance, uses the system's libav, has a bit of extra features
(such as less latency), and doesn’t use deprecated API’s. At some
point I measured exactly how much improvement compared to gst-ffmpeg
there is; it’s not much, but it’s some.
IOW; it’s possible that gst-av is the only GStreamer codec plug-in you
would ever need :)
Currently the supported codecs are:
audio decoding: Vorbis, FLAC, MP3
video decoding: H.263, H.264, MPEG-4, WMV, VP8
video encoding: H.263, H.264
But it should be easy to add support for more formats.
Currently the ogg-support package for Nokia N900 is in the process of
using gst-av, and all the identified issues have been fixed, so at
least there's a certain amount of people that have tested the audio