[Libav-user] re-encoding and transcode (codec copy) on same file.
I'm investigating if it's possible to do editing and transcode on same file.
I mean use -vcodec copy, we can readout packets and write them directly into output file without re-encoding. But if it's possible, for example if I have a 2 mins video, re-encode 1st min because there're some effects applied to that region but copy 2nd part?
My concern is, for example we know H.264 has extradata, if I re-encode first part but keep 2nd part, how if new extradata is different from old extradta?
Anyone have suggestion on this? and any other possible problems doing this?