The definition of rate and distortion is not conditional of lambda being

fixed (at least the current text sounded odd to me).

Originally committed as revision 18244 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2009-03-30 10:39:20 +00:00
parent 767e14c380
commit 52760ed76e
1 changed files with 4 additions and 2 deletions

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@ -21,8 +21,10 @@ Let's consider the problem of minimizing:
distortion + lambda*rate
For a fixed lambda, rate would represent the filesize, while distortion is
the quality. Is this equivalent to finding the best quality for a given max
rate is the filesize
distortion is the quality
lambda is a fixed value choosen as a tradeoff between quality and filesize
Is this equivalent to finding the best quality for a given max
filesize? The answer is yes. For each filesize limit there is some lambda
factor for which minimizing above will get you the best quality (using your
chosen quality measurement) at the desired (or lower) filesize.