Create a sandboxed playback element

Submitted by Johan Dahlin

Link to original bug (#607932)

Description

GStreamer should provide a playback element that separates the network IO and decoding from rendering. Demuxers and decoders are more likely to contain security bugs and should be separated as much as possible from the rest of the playback pipeline.

Source/demuxing/decoding should ideally be done in one process and communicate and send the data over shmem/pipe etc to another process which is only sending the decoded data to the audio and videosink.

See also:
http://code.google.com/p/chromium/issues/detail?id=32861#c23