Resolution & bit/pixel...whats the right?

[hippoth]

I have read a post from DJ Bobo...he wrote: "never go under 0,2 bit/pixel
For example: 640x480 25fps
-> Min Bitrate: 1536kbps (640 x 480 x 25 x 0,2)
So if GKnot calculates 1400kbps, choose a lower resolution, 576x432 for example." ...

... I thought every time the more higher the resolution so higher the quality?
What is right or what should be the max or the min resolution?
I´am a bit confused :confused:
Can you help me out?

[Got Milk?]

The higher the resolution the less blurry the film will look when you play it back fullscreen. But if the bits/pixel is too low (most people think 0.2) then there will be a lot of compression blocks which will obviously make the film look bad.

[llemor]

You can decide the best resolution based on the result of compressibility test. Of course, you don't have yet this compressibility test result initially, so you just choose resolution in which bits/pixel/frame is nearly equal to 0.20. Then run comp. test and notice the percentage of quality ratio. You may adjust the resolution to meet 50~60% quality ratio.

For me, I never go below 352xnnn. If quality ratio is still less than 50% with this value, I opt for 2 CDs. If quality ratio falls above 70%, I choose higher resolution than my initial setting.

[guirlle]

More resolution = less bits per pixel, you must search the middle point (Compressibility Check), if you think that having the higher resolution you get the higher quality, you are in a mistake. Becouse the pixels are less defined and when you go to the full screem you´ll notice it. This dont mean that you can have better results with a little higher resolution and a bits per pixel around 0.18 (In DivX5 0.20 I think is more than the needed, if you go to 0.19 even 0.18 you´ll have a good looking film)

SALUDOS

[DJ Bobo]

@ llemor
352x240 is a wrong resolution for DivX, so you may go to 320x240 or 384x288 (to have correct 4:3 ratio)

[llemor]

Oh, yeah, yeah. I suppose to write 352xnnn.:(

Thanks for the correction.:D

[hippoth]

hello people :cool:
i tried to encode my movie again in another resolution...my first encode was about 704x384 (0,227 bit/pixel) and the second has a resolution of 576x304 (0,351 bit/pixel)...both 2 cd rips!
They look both very nice (ok the second has more sharpness) but the second encode is about 150 mb to small...is it normal? My most rips I did with the resolution of 704x... and my calculation of the bitrate was always perfect!

What can I do to calculate it right?

AND:

Whats your primary favorite resoltion for your rips?

[Got Milk?]

The second file came out too small because there was too much bitrate allocated for the film. I.e. the film was encoded at maximum quality but there was still some spare bitrate. That wasn't at all grammiticly correct, but hopefully you get the idea :)

[hippoth]

are 1500 kbps to much for a about 100 minutes movie?

[Acaila]

It's definately more than needed (usually), but there's no law prohibiting you from using it :D

[hippoth]

Originally posted by Acaila
It's definately more than needed (usually), but there's no law prohibiting you from using it :D

Is there a way to use more? (don´t say 1-pass quality based!) because I have the impression the movie could be sharper...or what filter would you recommend? (but not for gk...it doesn´t wan´t my *.d2v :devil: )

[Acaila]

Neutral Bicubic resizing should do the trick, if you're not using it already. There's also some sharpen filters for VDub, but I never use those, because it's artificial sharpening anyway. Using the highest possible resolution also keeps the movie very sharp (if you've got the space you can go for whatever resolution lets you keep the full vertical information).

Check my sticky at the top of the page for things to increase the quality if you've got excessive space available.

[hippoth]

Originally posted by Acaila
Check my sticky at the top of the page for things to increase the quality if you've got excessive space available.
uuups...I don´t know what you mean?? :confused:



I have checked the two movie files (with the different resolutions)with a video codec id utility and found out that the file with the resolution of 576x304 has just an average bitrate of 1200 kbps...the file with the bigger resolution of 704x384 has an average bitrate of 1480 kbps (as it should be!!) ... how can I force the bitrate of 1500 kbps for the 576x304 file...it´s a damn when I have enough space :devil:

[DJ Bobo]

@ hippoth
Anta baka?! (it's an impolite question :D, check the japanese version of evangelion, especially what Asuka says all the time, if you don't know what it means -- hey, no offense, I just felt that it suits the situation :D)

There is a thread on top of this DivX5 forum called "Sticky: Undersized Files bla bla bla". You can't miss it!

[EDIT]
@ Acaila: I was faster ;)

[Acaila]

You should have guessed (if you'd read this (http://forum.doom9.org/showthread.php?s=&threadid=24584) thread) that a file at a resolution as low as 576x304 would be saturated at 1500 kbps. The lower the resolution the sooner it gets maxed out.
Increasing the resolution will increase the bitrate needed for max quality, and that's why the same movie at a higher resolution uses all the bitrate you give it.

@DJ Bobo:
Indeed you were :D

[hippoth]

@Dj Bobo & Acaila:

fast, faster...you are both ----:::<<< G R E A T >>> :::----!!! :D

i love it :cool:

@DJ Bobo: anta baka?...isasakamo nai :sly:

[DJ Bobo]

@ hippoth
nani?! :D

[HeSh]

anta? :rolleyes:
isn't the right word anata?

[llemor]

Yes, anata is the correct word.

But "anata baka" is really not a nice word, dame desu.:D

It's against the forum rule.:D :D :D

[hippoth]

shinnpaishinaide!!! :p