Doom9's Forum - View Single Post - telecide question

wotef · 13th December 2002, 05:58

hi neuron2, i'll answer this one -

let's look at the default script first and make things easier to see:

avisource("testhuff02.avi")
telecide(guide=1,chroma=true,blend=false,threshold=57,dthreshold=10,debug=true)
decimate(cycle=5,quality=3)
crop(8,100,-0,-104)
lanczosresize(720,552)

i look at (what becomes after decimation) frame 157 (i believe this originally frame number 195 or so)

if i look at the planet, i get this:

i pop the debug output / field choices into here:
http://www.zenadsl5618.zen.co.uk/w00tage/normal.csv

next, i run this script
avisource("testhuff02.avi")
tweak(sat=0,cont=11)
telecide(guide=1,chroma=true,blend=false,threshold=57,dthreshold=10,debug=true)
decimate(cycle=5,quality=3)
crop(8,100,-0,-104)
lanczosresize(720,552)

and i pop the tweaked debug field choices into here:
http://www.zenadsl5618.zen.co.uk/w00tage/tweaked.csv

if i compare a random row, there ARE differences, perhaps due to the noise threshold as you said, but i would interpret it as follows - in (low contrast/slow moving/albeit noisy frames) default telecide lace detection will consider certain frames as equivalent in terms of combing and be prone to choosing field patterns sub-optimally when compared to tweaking the same frame (desaturating, with high contrast); in the case of a low contrast tweaked frame, it would appear that the tweak can tip the balance and reveal resultant combing better such that telecide can make a more precise choice later about field patterns (edit - although i'm a bit confused now cause my example debug output shows telecide doesn't choose the lowest combed frame!! but it does change from a varying pattern to a cccnn cadence)

e.g.
normal:
Telecide: frame 194: p=5 c=4 n=10 using c
tweaked:
Telecide: frame 194: p=2502 c=2527 n=2601 using n

so, proof in the pudding, i now use the debug output from the tweaked job as an override file for the final run here:
avisource("testhuff02.avi")
telecide(guide=1,chroma=true,blend=false,threshold=57,dthreshold=10,ovr="tweaked.ovr")
decimate(cycle=5,quality=3)
crop(8,100,-0,-104)
lanczosresize(720,552)

and with frame 157 i'll now get:

should this not work? the frame choices are clearly influenced by the saturation and contrast tweak and the resultant file is visually much better

for now, my previous ideas still seem to produce beneficial results, even if my explanation as to why it works is not correct (didn't know about a noise detection threshold in telecide)...also never seen the mouth clip

...if there is benefit, then i still think the (contrast cap and floor) enhancement approach would work, too

eagerly awaiting your thoughts

13th December 2002, 05:58	#6 \| Link
wotef Registered User Join Date: Apr 2002 Posts: 272	hi neuron2, i'll answer this one - let's look at the default script first and make things easier to see: avisource("testhuff02.avi") telecide(guide=1,chroma=true,blend=false,threshold=57,dthreshold=10,debug=true) decimate(cycle=5,quality=3) crop(8,100,-0,-104) lanczosresize(720,552) i look at (what becomes after decimation) frame 157 (i believe this originally frame number 195 or so) if i look at the planet, i get this: i pop the debug output / field choices into here: http://www.zenadsl5618.zen.co.uk/w00tage/normal.csv next, i run this script avisource("testhuff02.avi") tweak(sat=0,cont=11) telecide(guide=1,chroma=true,blend=false,threshold=57,dthreshold=10,debug=true) decimate(cycle=5,quality=3) crop(8,100,-0,-104) lanczosresize(720,552) and i pop the tweaked debug field choices into here: http://www.zenadsl5618.zen.co.uk/w00tage/tweaked.csv if i compare a random row, there ARE differences, perhaps due to the noise threshold as you said, but i would interpret it as follows - in (low contrast/slow moving/albeit noisy frames) default telecide lace detection will consider certain frames as equivalent in terms of combing and be prone to choosing field patterns sub-optimally when compared to tweaking the same frame (desaturating, with high contrast); in the case of a low contrast tweaked frame, it would appear that the tweak can tip the balance and reveal resultant combing better such that telecide can make a more precise choice later about field patterns (edit - although i'm a bit confused now cause my example debug output shows telecide doesn't choose the lowest combed frame!! but it does change from a varying pattern to a cccnn cadence) e.g. normal: Telecide: frame 194: p=5 c=4 n=10 using c tweaked: Telecide: frame 194: p=2502 c=2527 n=2601 using n so, proof in the pudding, i now use the debug output from the tweaked job as an override file for the final run here: avisource("testhuff02.avi") telecide(guide=1,chroma=true,blend=false,threshold=57,dthreshold=10,ovr="tweaked.ovr") decimate(cycle=5,quality=3) crop(8,100,-0,-104) lanczosresize(720,552) and with frame 157 i'll now get: should this not work? the frame choices are clearly influenced by the saturation and contrast tweak and the resultant file is visually much better for now, my previous ideas still seem to produce beneficial results, even if my explanation as to why it works is not correct (didn't know about a noise detection threshold in telecide)...also never seen the mouth clip ...if there is benefit, then i still think the (contrast cap and floor) enhancement approach would work, too eagerly awaiting your thoughts Last edited by wotef; 13th December 2002 at 06:07.