[FFmpeg-devel] [PATCH] RoQ video encoder (take 4)
Fri Jun 15 00:09:56 CEST 2007
On Thu, 14 Jun 2007, Eric Lasota wrote:
> By the way, why does the rate control target rate lambda instead of
> total distortion, since base distortion can vary and cause quality to
> shift while lambda remains the same?
Lambda (or equivalently, quantizer) is the only thing that a ratecontrol
algorithm can decide. Distortion isn't known until after you encode the
frame. Now, a ratecontrol algorithm could use some heuristic to guess a
lambda that might provide a given distortion, rather than guess a lambda
that might provide a given bitrate. The reason no such mode exists is
that you haven't written it.
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