Xvid Quantizer Codecs

[theninger]

A slight problem. Recently I've been converting h264 to xvid using the quantizer with the ultra setting in conjunction with h263 matrix. However the output video size is unpredictable despite using the same quantizer value and I pretty much had to trial and error to get it to a specific file size (so it can fit on a dvd). There is a number of videos by the way. Just wondering whether there is a program or something that can predict the output size of video using quantizer value. I know of the fact that there are numerous one that can calculate bitrate but I have never found one for quantizer. Thanx for your help and input.

[45tripp]

However the output video size is unpredictable despite using the same quantizer

unpredictable because of using the same quant.

Just wondering whether there is a program or something that can predict the output size of video using quantizer value.

there's an old program called enc which'll give you size prediction based on a sample constant quant encode.
but i can't think of something right now which will run a series of q encodes to estimate a q value for a given target.


tripp

[theninger]

However the output video size is unpredictable despite using the same quantizer

unpredictable because of using the same quant.

Just wondering whether there is a program or something that can predict the output size of video using quantizer value.

there's an old program called enc which'll give you size prediction based on a sample constant quant encode.
but i can't think of something right now which will run a series of q encodes to estimate a q value for a given target.


tripp

Despite is rught. I meant the quantizer value. Nevertheless thanx.

[jagabo]

That's the whole point of constant quantizer encoding. It's a constant quality mode. The video comes out whatever size is necessary to maintain the quality you specify (via the quantizer).