Hi Brian, Brian Cameron wrote: > Alfred: >>> Is there any relationship between Coherence and gstreamer ? >> Thanks for pointing this out. Currently, Coherence implements a >> transcoder for local audio files (audio/mpeg, audio/ogg, audio/x-wav, >> audio/x-m4a etc.). Transcoding is done with a GStreamer pipeline and a >> custom sink that writes to a http request. So Coherence requires the >> GStreamer FFmpeg plug-in to do so. > > What is the specific requirement that Coherence has on FFmpeg? Please > explain. Coherence can do transcoding when it acts as a media server as this link points out: http://coherence.beebits.net/wiki/TransCoding. Please note that this document is out-of-date. I just did a search to the source code and the ChangeLog. Coherence has a gstreamer-based transcoder (untested) to do passthrough to MP4 (H264/aac). This can be used by AppleTrailers backend to transcode the movie trailers (video/mov?) to video/mp4.
The output of gst-inspect on my box shows that ffmpeg has the MPEG-4 compatible video encoder/decoder. So I think GStreamer ffmpeg plugin could be one of the choices to do the transcoding for Coherence. Fluendo plugins might be another choice, but I can't confirm as I don't have the codecs on my box. > Are you sure that this requirement can't be met via a non-FFmpeg > solution. If coherence needs MPEG-2 or MPEG-4 support, or other > non-free media support, then I would think that the Fluendo plugins > would also work. Someone who has the fluendo codecs could help confirm this. > I wouldn't think there would be any special relationship between > coherence and GStreamer. Aside from the fact that some media > programs like totem, rhythmbox and elisa pull data from UPnP > servers and play them via a GStreamer pipeline. The Coherence transcoder depends on GStreamer as I can tell from the source code. And Coherence implements the transcoding via gst-python. Guess we'll have to include the ARC case gst-python (PSARC/2008/105) in the "Imported Interface" table. Best Regards, -Alfred
