The difference in framerate was HUGE for our show. We do a lot of high energy, high velocity action footage.
I thought it looked good on 15fps, but then someone here said that moving to 29.97 wouldn't double the file size, or double the bitrate (I think it was you Elbows...). I did and our footage was much more appealing. I think we got a 25% or so file size increase, but it's more than worth it. Of course, if you're sitting in front of your camera, or otherwise not moving a lot, it shouldn't matter. See for yourself: 15FPS: http://blip.tv/file/get/K9disc-theArtOfK9DiscRememberTheSun514.mov http://blip.tv/file/get/K9disc-theArtOfK9DiscRememberTheSun514.flv 29.97FPS: http://blip.tv/file/get/K9disc-RememberTheSun2997Fps973.mov http://blip.tv/file/get/K9disc-RememberTheSun2997Fps973.flv I don't know if the FLV versions pick up the same quality change. I have not checked them. Cheers, Ron Watson On the Web: http://pawsitivevybe.com http://k9disc.com http://k9disc.blip.tv On Apr 24, 2007, at 12:57 PM, Steve Watkins 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 [email protected], "Bill Cammack" <[EMAIL PROTECTED]> > 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. > > > [Non-text portions of this message have been removed]
