I can accept that as an alternative. Instead of changing FPS, change the rate of keyframe appearance.
-- Bill C. BillCammack.com --- In videoblogging@yahoogroups.com, "Steve Watkins" <[EMAIL PROTECTED]> wrote: > > The effect of changing framerate isnt quite that straightforward, as > most web formats use temporal compression. Instead of each frame being > compressed in full, only keyframes contain the full image info. The > frames that arent keyframes, just contain info about what has changed > since the previous frame. This can be a highly effective technique, > and means that how often you have keyframes will likely determine the > necessary bitrate more than your frames per second will. > > This is one reason why I have always suggested people try > experimenting with higher framerates in their vlogs, dont assume that > it will make the compression articfacts twice as bad if you double the > framerate, or that you need to make the bitrate twice as high to > compensate for having twice as many frames. Nor should twice the > framerate automatically be assumed to require twice as much CPU power, > battery power etc to decode. > > Its also another example of Apples advice differing from the > historical advice given by most in this group. Apple have never > recommended using 15fps but thats often been the advice here. > > Certainly I couldnt declare 'everyone should use 25 or 29.97 or 30 > fps' because 15fps is going to work better for some under certain > circumstances, there is no 'right answer' although I expect higher > framerates will become the norm eventally, as most portable devices > can handle them ok there is no hardware barrier to this, more > perception than anything else) > > Cheers > > Steve Elbows > > --- In videoblogging@yahoogroups.com, "Bill Cammack" <BillCammack@> > wrote:Your only way > > around that is to encode at a lower FPS so that you retain quality at > > the expense of smooth, fluid motion, say, coming down from 30 fps or > > 29.97 to 15fps. That way, you could get twice as much data per frame > > because you're outputting half the number of total frames in the same > > amount of time. >
