Whats up with x264 development?

[futurex]

There must have been about 5 or 6 builds in the past 24 hours! just curious as to what's going on with this sudden developing frenzy. lmao the nex 2 builds will be out by the time i finish this encode. definitely a good thing! :D

[ChronoCross]

There must have been about 5 or 6 builds in the past 24 hours! just curious as to what's going on with this sudden developing frenzy. lmao the nex 2 builds will be out by the time i finish this encode. definitely a good thing! :D

why did you make this thread it's pointless. Perhaps they got some free time, or a sudden idea spurt happen, or they just decided to do it. who knows. sheesh

[futurex]

who knows. sheesh

obviously you dont. your reply in this pointless thread is also pointless

[ChronoCross]

obviously you dont. your reply in this pointless thread is also pointless

I enjoy replying to threads no one else will. Entertains me. Your asking a stupid question. Almost as bad as "why is the sky blue"

Seriously some days will be lots of commits, other days will be none. no sense arguing the reasoning behind it.

[soresu]

Sounds to me like pengvado got the urge to do some major optimisations :D

Keep up the good work !!

[Doom9]

Almost as bad as "why is the sky blue"Actually, that's quite a good question if the answer gets into the scientific details. Ask 10 people on the street, I'm sure 9 can't give the right answer to this question.
But it's pretty pointless to ask about open source projects, any free projects really.. they live and breathe by the people participating.. you know as well as the next guy that motivation can fluctuate and so can available time.

[DarkZell666]

Why is the sky blue ?

Probably because the sea below is blue ...

But why is the sea blue (well, green in some places ... xD) ?

Reminds me of the egg and the chicken thing really ^^'

[akupenguin]

Almost as bad as "why is the sky blue"
Why do people use that as an example of what not to ask? It's a perfectly valid question.
The sky is blue because short wavelengths of light (blue) are more likely to scatter when they hit an air molecule, while long wavelengths (red) are much bigger than air molecules, and are less likely to scatter. If you're looking at a piece of the sky that's not occupied by the sun, then any light coming from that direction is not coming directly from the sun, thus what you see is what has been scattered.
:D

[DarkZell666]

ROFL :D

Nice Physics lesson ;)

[GodofaGap]

And when there are bigger particles in the air (like smog or dust), it gets a more whitish color because light of longer wavelengths (red, orange) is more likely to be scattered too then. For the same reason the sun turns orange/red at sunset, because the light has to travel a longer way through the atmosphere than during daytime, which causes all wavelengths to be almost completely scattered but the longest. So the only light from the sun directly reaching your eye is red and orange then. :)

[MeteorRain]

Then why do you discuss about the blue sky in x264 development forum? just curious about this

[Doom9]

@aku: thanks.. I only recalled half of that. I would've had to take out my high school physics notes.

[nurbs]

The sky is blue because short wavelengths of light (blue) are more likely to scatter when they hit an air molecule, while long wavelengths (red) are much bigger than air molecules, and are less likely to scatter.

Small correction. In both cases the wavelenght is much larger than the size of the particles. In such a case Rayleigh scattering occurs and the light is scattered proportional to lambda^(-4). Accordingly blue light is scattered ~10 times more efficiently than red light.:)

If particles were indeed much larger than the wavelenght of the light the scattering would be independant of wavelenght, like when there is fog.

[kopavel]

Why the light with shortest wave is blue (violet... ultraviolet... :D) and with longest wave is red(infrared...)? :D :D :D

[DarkZell666]

Because the light-sensitive cones in our eyes have different sizes ? Might they work like a radio antenna, reacting only to a predefined frequency ?

[lexor]

Why the light with shortest wave is blue (violet... ultraviolet... :D) and with longest wave is red(infrared...)? :D :D :D
arbitrary choice by random people who came up with names. it's just like Fahrenheit 0 degress is defined to be the room temperature in the lab where the guy studied the temperature and came up with the scale, it seemed like a good place to defines 0 to him. Our eyes differentiate colours, and we arbitrarily chose to call them the names we have now, there really is no good reason for the names other then people felt like it.

as for x264, you don't know they coded it that fast, there was a somewhat longish break with no updates, I think they just commited the code in a batch.

[CruNcher]

Nice explanations but are those still valid in Quantum Space ? ;)

[Sharktooth]

no... but are valid in codec development... expecially in HVS tunings.
the number and type of receptors inside the eye are not the same for all frequencies.
also there are zones that does not have receptors at all. in those zones the human eye is completely "blind" but the image is compensated while processed by the brain, so you have the "illusion" you see everything.
also the receptors in peripheral view are more sensible...
well... there are indeed a lot of things to know...

[ChronoCross]

Why do people use that as an example of what not to ask? It's a perfectly valid question.
The sky is blue because short wavelengths of light (blue) are more likely to scatter when they hit an air molecule, while long wavelengths (red) are much bigger than air molecules, and are less likely to scatter. If you're looking at a piece of the sky that's not occupied by the sun, then any light coming from that direction is not coming directly from the sun, thus what you see is what has been scattered.
:D

Or you could go the theological route. The sky is blue because god made it taht way. Both being valid answers depending on what ebliefs you subscribe. heh

[Niddhogg]

Or the Flying Spaghetti Monster (http://www.venganza.org/) for that matter.

The interesting thing is that we might all see 'green', 'red', 'pink' or whatever as a completely different colour as others do.
Makes 'my favourite colour is ...' rather useless of course... :rolleyes:

[siddharthagandhi]

The sky is blue to signify the alien invasion.

9 years, 4 days, 6 hours, 44 minutes, 30 seconds.

They Are Coming.

You can run, but you can't hide.

No one is safe.

Armagadeon is inevitable.


_

[DarkZell666]

Or you could go the theological route. The sky is blue because god made it taht way. Both being valid answers depending on what ebliefs you subscribe. heh

I believe that you need a new pair of fingers xD

[akupenguin]

The interesting thing is that we might all see 'green', 'red', 'pink' or whatever as a completely different colour as others do.
Might? I know I see colors differently than other people. Colors in the real world consist of a continuous distribution of light intensities across the spectrum, and the human eye samples just 3 points on the spectrum. You can think of the points as red, green, and blue, though actually the red and green sensors are close in frequency, while the blue is farther removed. Also, each one isn't a single point, but has some response curve over a range of the spectrum, and they overlap. Anyway, the mapping of a real-world color into an RGB (or YUV, whatever) triple that's supposed to look the same, depends on that response function in the human eye. But not all eyes are the identical.
There was this neat experiment in my local science museum, whereby they show you a pure color (e.g. some setting on a variable frequency laser), and you dial up the RGB values that look the same to you. Then you compare it with what other people dialed for the same laser. Of course, that's only a lower-bound on the differences between peoples' perceptions; it doesn't answer the philosophical question about what we "really" see that we've all just learned to call "chartreuse".

[Avish]

Is this the "Official Off Topic Thread"?? :rolleyes: :D :p

[sasam]

Sky isn't blue anymore, it used to be before the industrial revolution, now it is gray or maybe evolution has changed our perception of colours. Who knows http://img142.imageshack.us/img142/7364/crazy2zd.gif

[bob0r]

So..... has anyone seen MacGyver last night?

[Sirber]

I have troubles with installing ATI driver in Ubuntu. X always say "failed to load module", but it's there. Any clue?

[celtic_druid]

I almost missed it because my TV was broken, but I managed to make a new one out of a ruber band, a straw and a paper clip.


PS. The straw was blue.

[sade]

According to one theory, the number of colors you can distinguish depends on the number of words you have for them. I probably couldn't distinguish between normal green and chartreuse because I neither heard nor used the latter before.

[*.mp4 guy]

According to one theory, the number of colors you can distinguish depends on the number of words you have for them. I probably couldn't distinguish between normal green and chartreuse because I neither heard nor used the latter before.

Thats just an urban legend and isn't chartreuse red. Distinguishing between colors is tricky, try looking at a gradient where you can easily distinguish between two very similar colors, then seperate them and look at them individually, it should be much harder when they are separate.

[emmel]

I'm colour-blind, and I have developed my own colour space. I call it Y.

[foxyshadis]

Or the Flying Spaghetti Monster (http://www.venganza.org/) for that matter.

The interesting thing is that we might all see 'green', 'red', 'pink' or whatever as a completely different colour as others do.
Makes 'my favourite colour is ...' rather useless of course... :rolleyes:
Apparently yes. @_@

[Audionut]

I enjoy replying to threads no one else will.


LMAO.:stupid:

[rushin_911]

I have troubles with installing ATI driver in Ubuntu. X always say "failed to load module", but it's there. Any clue?

I have some problems with that too. It installs for me however if calls the rendering to be done by mesa instead of ATI's making the whole point behind it worthless (and making me not able to use the nice Xgl eye candy :( )

[mod]

The sky isn't really only blue, it's a lot white and blue noisy because of limited spatial resolution of human eye.
When D/λ << 0.01, automatic postprocessing makes it seem blue
Of course for D/λ ~ 1 postprocessing is off, or we would miss the stars. :D

[Sirber]

I have some problems with that too. It installs for me however if calls the rendering to be done by mesa instead of ATI's making the whole point behind it worthless (and making me not able to use the nice Xgl eye candy :( )Well, those drivers are usefull for OpenGL acceleration. Normal "ati" drivers are software only.

[lexor]

The sky isn't really only blue, it's a lot white and blue noisy because of limited spatial resolution of human eye.
When D/λ << 0.01, automatic postprocessing makes it seem blue
Of course for D/λ ~ 1 postprocessing is off, or we would miss the stars. :D
you can see stars durring the day? wow you good!

[Niddhogg]

I'm colour-blind, and I have developed my own colour space. I call it Y.
Wow.
1. Total or partial colour-blind ?
2. And always been or later acquired ?

Regardless, is nice excuse for me to read more Wiki's :
http://en.wikipedia.org/wiki/Colour-blind
http://en.wikipedia.org/wiki/Monochromat

Now an attempt to get back on topic (somewhat) :
3. Does encoding a film noir in 4:2:0 take up more space than in 4:0:0 or does the (x264) codec take that possibility actually into account ?

Some of the world's best movies (a disproportionate part at that, imho) are B/W (or coloured in), so... :o

[emmel]

No, I just hate red, coz its the colour for girls. Then, I studied things a bit more and discovered that Y is so widely used that I decided to call my new thing "Why".

[Sirber]

Isn't "pink" the girl's color (and the girly men)?

[LordRPI]

There was this neat experiment in my local science museum, whereby they show you a pure color (e.g. some setting on a variable frequency laser), and you dial up the RGB values that look the same to you. Then you compare it with what other people dialed for the same laser. Of course, that's only a lower-bound on the differences between peoples' perceptions; it doesn't answer the philosophical question about what we "really" see that we've all just learned to call "chartreuse".


Close one of your eyes and look at a colored object. Switch eyes and see if you can see even the slightest difference in that color perception. It works better if you've been laying down on one side of your face shortly before.

[soresu]

Surely thats just due to limiting the bloodflow to retina and optic nerve, not an actual difference in perception. The perception of each different colour is determined by the photosensitive reactions of the three different colour pigments in the 'cone' areas of the retina, and the brains interpretation of the nerve impulses that are transmitted back to the brain by the optic nerve. Without sufficient bloodflow, the nerves cannot function optimally, and therefore an incomplete interpretation of the colour is made. As such, in colour-blindness - the brain has formed a visual recognition area in a different configuration, and the nerve impulses are interpreted in a different order.

[LordRPI]

Who said perception due to physical differences in the eyes wasn't a difference in perception...

[Kopernikus]

Another interesting thing to do with a blue sky and human perception:

Look at the blue sky (it works best if its really blue and no clouds are there) and you can see the blood cells flowing through the blood vessels on your retina as small dark dots.

[*.mp4 guy]

Surely thats just due to limiting the bloodflow to retina and optic nerve, not an actual difference in perception. The perception of each different colour is determined by the photosensitive reactions of the three different colour pigments in the 'cone' areas of the retina, and the brains interpretation of the nerve impulses that are transmitted back to the brain by the optic nerve. Without sufficient bloodflow, the nerves cannot function optimally, and therefore an incomplete interpretation of the colour is made. As such, in colour-blindness - the brain has formed a visual recognition area in a different configuration, and the nerve impulses are interpreted in a different order.

Its a hell of a lot more complicated then that. for instance on a sunny day close one eye and keep it closed for a few minutes, before you open it look at a brightly colored object, then swith eyes, It should look different (most likely it will look like its tinted blue). Or if you have tinted sunglasses (yellow works very well) keep one eye closed and look through the sunglasses with the other eye, when you take the sunglasses off the eye that was open will percieve everything as being tinted the opposite color of the sunglasses.

[Edit] And color blindness is caused by malformed cones or missing cones in the eye (or atleast some color blindness is, I don't know if this accounts for all color blindness).

[Audionut]

Jesus. You guy's should become optometrists.

When I look at a blue sky, I see a blue sky. Or is it yellow.
After reading this thread, I'm soooo confused.

[GodofaGap]

Actually it's pink with polka dots. Or did I just stare at the sun for too long?

[Niddhogg]

Think this should 'clear up vision' :p :
Rod cells (http://en.wikipedia.org/wiki/Rod_cell)
Cone cells (http://en.wikipedia.org/wiki/Cone_cell)

Spectral range of the rods & cones :

http://upload.wikimedia.org/wikipedia/en/c/c2/Cone-response.png

Rod
Long wavelength cone
Medium wavelength cone
Short wavelength cone

Notice how close 'red' and 'green' cones sensitivies are...