[Ffmpeg-devel] Adding a file type, and VIC codecs

[Derek Piper]

	Hi,

	I have a question about VIC codecs, and I've not been able to find an 
answer. As I understand it, ffmpeg (libavcodec) and VIC have different 
implementations of H261 and H263. Is anyone trying / has anyone tried to 
add the VIC implementations of the codecs to ffmpeg and libavcodec so 
that it is possible to decode frames from VIC into something ffmpeg can 
understand and from there convert to another target format?
	I am interested in this as I have written an application that captures 
audio and video data from an AccessGrid conference. AccessGrid uses the 
MBone tools VIC and RAT for videoconferencing. My program is called 
AGVCR and has been released for nearly a year now and has improved 
considerably in that time. AGVCR can record almost unlimited video and 
audio sources from effectively any number of RTP/RTCP connections. One 
of the features I am interested in adding is being able to convert an 
AGVCR recorded file (reduced down to only one video and audio source) to 
an MPEG or similar file for ease of distribution.
	In conjunction with the work from another individual, I would like to 
add the AGVCR file specification to libavformat. Is that something that 
might be possible to do?. At present, that reader works for the files, 
the only problem is the H261 frames cannot be decoded by the standard 
H261 decoder that ffmpeg has.
	If it were possible (and it's certainly not a small job) to add the VIC 
codecs to libavcodec, would that be something welcomed by the ffmpeg 
maintainers? I want to ask this before any work starts on it so that if 
it's not acceptable for certain reasons that I understand this and work 
on an alternative solution and not waste time on it.
	If anyone is interested in learning more about AGVCR, you can simply 
email me directly off-list. I won't spam this list with adverts for my 
own program :)
	Please let me know what the view is on adding VIC codecs. Obviously 
they would be differentiated from the ffmpeg versions, e.g. 'vich261', 
'vich263'.

	Thanks,

	Derek

-- 
Derek Piper - dcpiper at indiana.edu - (812) 856 0111
IRI 323, School of Informatics
Indiana University, Bloomington, Indiana