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View Full Version : The crappy world of 1-pass VBR VP6


veryhappyjk
16th September 2004, 11:17
I've been using VP6 for some months, after which I've switched to XVID.

However, I'll writing some notes about VP6.

I've always used one-pass VBR with all codecs, however it seems On2 didn't care a f*ck about this mode and put up only a mess.
Or they cared, in that case the programmer is simply an i**ot.

Here are various options and results.

They demonstrate many options are totally useless in one-pass VBR, though they are ENABLED, and how there isn't a REAL quality selector.
Just a totally confusing interface.

The sample is a precise-bicubic resampled 360x288 took from Brazil (T.Gillian), VTS_01_4.VOB first 4501 frames.

Constant options are:
Mode = 1 pass/best qual; End usage = VBR, Material = Progressive, Noise r. = Off, Keyframe on 300 max, Sharpness = 7
Advanced: Adjust quantizer = Yes.

bitrate,undersh,quant./min/max,temp.res.,spat.res.,size
300 90 4/56 N N 6884
3000 90 4/56 N N 58720
300 90 56/56 N N 1752
300 90 4/4 N N 44170
300 90 4/56 Y/20 N 6884
300 90 4/56 N Y/35/45 6884
300 50 4/56 Y/20 Y/35/45 6884

"Bitrate" influences bitrate in 1-pass VBR, but it really doesn't make any sense [in 1-p VBR]
"Min" and "Max quantizer" also influence bitrate, and it also doesn't make any sense if we're using 1-pass with constant quality.

Undershoot, Temporal resampling, Spatial Resampling are useless in [1-p VBR].



Bye bye (VP6!!!)
Saverio M.

stephanV
16th September 2004, 12:01
you are misunderstanding the 1 pass VBR mode in VP6 completely

it *is* a bit rate based mode therefor temporal and spatial resampling dont influence the result, it will always try to achieve the bit rate and can only be prevented from doing so by limiting the quantizers. 1-pass Best Quality is *not* the same as XviDs single pass constant quality/quantizer.

before you make an idiot out of yourself by calling others just that, you might actually try to do some reading on the codec you are using. there comes a rather simple document with it.

this was just a dumb troll.