i made my own nnedi comparisons tests with avisynth,

spline36 in nnedi cshift worked even better than lanczos3 or 4 on its own or in cshift,

will only need to test spline64 in cshift now…

yeah well. at least, the dvd was cheap.

Oh…btw…as far as I know, during the first weekend the movie was in the US cinemas people paid enough money for the tickets to pay for the whole production. This either means that the US citizens have a very bad taste or that the production was cheap.

Well…bad decision to buy this DVD. You should have asked me beforehand and I would have warned you. Maybe you can sell it on Ebay…or use it as a coaster. ;D

wow, nice Work Jean

interessantes Hobby hast du!

Gruß Dominik

Thanks for the pingback…always surprises me when people find that article.

I’ve been reading your article…and I’ve got a few things I’d like to add to it (although I haven’t read the previous one).

For starters, 5.1 sound is far from perfect as far as our ears are concerned. The human ear picks up sound from a full 360 degrees…and the entire deal of processing that sound is huge. The human hearing is really quite advanced and does all sorts of stuff you may not realize. For example…sound direction isn’t determined by exactly what ear obtains the information. What you said about the Haas effect is somewhat true….however the Haas effect is often incorrectly used to describe the underlying process of the precedence effect, and it basically says when similar sounds are coming from different locations, our ears localize it to the first one heard. But that relies on the delay being very small…but it largely has use with sound reinforcement systems..in which you don’t want to disturb the original ‘soundstage’ but want to make sure people can hear it..so generally they’ll delay the audio to distant speakers by 20ms and amplify it a bit….meaning people closer to those speakers still have the whole illusion of the sound coming from the original source..rather than from a speaker. This doesn’t apply to the stereo in your living room…but rather…is more of use in say a concert hall when you’re using sound reinforcement. The further away from the stage you are, the harder it is to hear…so the speakers further from the stage have processing applied so that, to the people near them…the sound isn’t coming from the speakers behind them…but from the stage.

The other aspect that’s interesting about sound…at least in a natural environment is the way we perceive it. I had an ear infection the other year and my right ear was 98% blocked. I couldn’t hear anything out of it except muffled voices (since the ear canal naturally amplifies those sounds) and anything cranked WAY up. But one thing I noticed is that if a sound came from the right side of my head…despite not being able to hear it from the right ear, i could still tell it was coming from the right side. The best I could figure out from studying the inner ear is that there are additonal bone structures that detect vibrations and help with directional sound….but the other kicker is for sounds below 1000hz. Below 1000hz the waveform is long enough that it actually wraps around the head the same way a low-frequency RF signal follows the curvature of the earth. So our brains developed a way of doing phase discrimination…and this may play in to the precendnce effect as well. If a sound is coming from the right…then it would hit the right ear, curve around the head and hit the left ear…however, it’s phase would be changed…it’s this change in phase that helps the brain determine where the sound is coming from. This is actually why the higher the frequency…the more difficult it is for our brains to determine what direction it’s comming from.

5.1 is a different game. The amount of delay you’re dealing with in your home stereo is rather small. Some systems will allow you to adjust the delay of the rear speakers…somewhat enhancing the effect….however, I still say phasing plays a lot in to it. Take a 4.0 system for example. You can still get the effect of having a center speaker by mixing audio evenly in to both channels and maintaining it’s phase.

When you stated that you opened a DVD that was mixed in 5.1 and the left/right contained no vocals…that’s perfectly normal. In most movies..the dialog is pretty much the center of the action and therefore goes to the CENTER channel. The front left and front right only basically containing directional sounds. It’s not proper to say it would contain all the sound in front of you….that would create a pretty false confusing sense of surround. They do..sometimes…contain some of the rear audio information…but delayed or with a different phase. When the sound from the rear hits your ears…likely due to the precdence effect (which I stated didn’t apply as much to home theater but I’m kind of brainstorming as I write this)…you percieve it from the rear. It also allows you to get a more accurate surround stage…say something is comming from DIRECTLY left of you…well…if you were sitting in an ideal surround setup…if you evenly mix the audio between the front and rear left’s….you’ll get this effect that it’s coming from the side. It’s like in my truck, which has speakers in the door and speakers behind the seat it sounds like the sound is coming from a location that has no speaker. If you had a vocal coming from the left AND center…it would sound like it was coming from just left of center….again..possibly due to hass-like effects…but again..i’m not that kind of audio engineer and since I don’t do sound reenforcement…I’ve never studied it…but i’ve likely encountered the same thing in mixing.

What you’ve done is quite simple…and while i’m not knocking it…I don’t think it’s how I would of done things. For starters…LFE is not just the “subwoofer” channel…it’s far from it. LFE is actually designed for effects that contain a lot of sub-sonic components that are routed to a subwoofer which gives the extra punch…almost the physical punch of the sound. AC3 assumes you have full-range speakers on each channel and if, for example, you have something bassy in the left…then it might be solely left and have no LFE. But…with the way modern systems are designed…we use rather frequency limited drivers and make up for it with a subwoofer…so MOST systems have the ability to redirect the bass from EVERY channel to a subwoofer. Bose was pretty much the first to popularize this. I will admit…you can get away with it…possibly because the aforementioned effects will allow the bass to come from somewhere else but with a slight bit of direction…come from the proper location…but…you don’t need to route all the low-end to the subwoofer. The stereo will do that if needed…otherwise…you’re creating a mix that sounds good on YOUR system…but someone who has full range speakers on thier home theater (like..for example…I do happen to have full-range speakers on all channels and when i’m doing something like playing music…the subwoofer is..surprise…mostly silent).

but I think you’ll find that if you actually get in to some of the channel seperation techniques out there that use FFT phasing…like the stuff I mentioned or the even better Center Channel Extration which is in Adobe audition which you don’t use since (I assume) you’re a linux guy….even just doing slight gentle stuff yields amazing results…and even if say your center channel sounds slightly distorted…you could use un-seperated left/right audio with your seperated center at half-amplitude and GREATLY enhance the whole 5.1 effect.

I can’t help you much on what to do for rear channels. Most 5.1 content…even music…is a true 5.1 mix and taking the left/right only content and throwing it in the rear just…it kind of sounds funky.