Andrea Giuliano wrote: > Hi! > > I've been using for a while a simple BASH script I wrote to get Xvid > files out of MJPEG edit lists. It just works for me, but it uses the > same options for both passes. > > I guess some options are useless in the first pass, that could be faster > if those options are avoided. For example, does it make sense, during > the first pass, an option like "-J smartyuv", or like "-J fields=shift"? > I would say it doesn't. > > I'm also in doubt for Z, Y and other clip/zoom options, and -E or other > audio related options. Could they be used just in the second pass, or > are they mandatory in the first pass, too?
Well, some things will totally screw you if you omit them from the first pass... But I have omitted the cmp and subcmp options from the ffmpeg.cfg for the first pass with no visible effect on the result, but a huge speedup on the first pass. You can also safely use the null audio decoder/encoder and pick up about 10% speed. Cropping should NOT be omitted, since you are HOPEFULLY using it to crop out things that would steal bandwidth otherwise, like sideband cruft and black borders.
