Quote:
Originally posted by h9903209
just come up a question, if I use 450 to encode, the resulting file average bitrate becomes say 550, I suppose it's because it "feels" needs that extra bitrate for better quality, right? so comparing with this new rate control, which the resulting file bitrate must be close to 450, then the qualitity would be lower (compare to the previous one with average bitrate 550) though filesize would be smaller, right?
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I am not sure I understand your question, but yes, an encoded clip at a bitrate of 450 kbps will have a smaller filesize and lower quality than 550 kbps
If you are not very concerned about filesize, and you have a short clip, then perhaps the old rate control is just what you need. If you would like very accurate filesize and/or achieve constant quality for the whole clip, low and high action, then this new rate control is just right.
I used the new rate control to encode an important demo, 15 minutes or so of high and low action, categorized as very hard material. The requested parameters were 352x152 @ 800 kbps
Someone else first used the old rate control, and even at 480x208 the high action scenes looked rather blurry with the old rate control. With the curve compression method the whole clip looked great throughout at 640x272. So it has already gotten some useful mileage.
Oh, while I remember, on another topic:
Previous B frame parameters
Generally these are not needed, especially not with this update, However:
patternAdaptivity: still works, but locks the B frame pattern, i.e. turns off adaptivity. Allow values are 0,1,2,3.
scalingFactor: Works only with previous rate control. Turns off adaptive quant scaling for B frames, and locks the scaling factor.