YouTube HowTo: Lossless/unchanged color??

[Random1776]

Okay people, this is a major problem!

(first: i just want to make it clear here that this concerns videos that we *know* for sure are supposed to be Rec.601)



When you upload a video to YT, that you know is Rec.601, the color seems to always change to Rec.709 when YT converts the file.

I know this is an extremely common problem. In fact, it seems like it happens to everyone. It's just that (most) people seem to not care.

I know this because I've tested this thoroughly with a particular anime series in which it's VERY easy to see the change from Rec.601 (the correct color) to Rec.709. It seems to have happened to everyone else who has uploaded videos from that same series. What I mean is, to make it more clear; the way I can tell for sure (although I usually spot it anyway), is simply by comparing the YT video to how it looks in MPC. If I change the color in MPC from 601 (or from auto) - the correct mode - to 709, then it looks the same as on YT.

One other strange thing is that if I request the very low quality &fmt=5 version (which is not an H.264 stream) the color looks normal - it looks like Rec.601 again!

Ok, so here's the thing:

I upload in FFV1 (ffdshowtryouts) - which is lossless and YT accepts it, which is very nice...

But regardless of what colorspace settings I use (YV12, RGB32, etc) when encoding the FFV1 file, when YT converts it the color is always messed up and looks like Rec.709. If YT isn't really converting it to Rec.709, then it's at least doing *something* to change the color so that it appears to be just like as if it was changed to Rec.709.

I just wish to be able to upload videos and have them be the same color as the original source.

Is there any settings on the users/uploaders side that can be used within ffdshow to solve this? Or... is there nothing we can do and YT always make the videos Rec.709 regardless...?

And, what would be the best colorspace to use in FFV1 for achieving an as lossless a color as possible on YT?

[titigrom]

This is very interesting !
Maybe you can find more infos about how colorspace and compression are tied (h.264 as we know performs high compression rate).
I remarked that too but I didn't look for any details about that. I thought the player in YT makes the picture smoother. MPC plays the same video I downloaded within ffdshow a little bit different.

[hech54]

It's just that (most) people seem to not care.

You're right....nobody cares. It's YouTube....not the national Archives.
NEXT

[Bonie81]

Random1776

nice research for which you owe YT or YT should pay high bucks to you. LOL!

infact, It's YouTube....nobody or who cares!
i already stop uploaded high quality videos to YT.

[themaster1]

It's a very valid question because i'm trying to figure this out at the moment.
My guess is unless you don't pay youtube (be a youtube partner for instance) then you haven't the option to send a file losslessly and have it not reencoded. No matter what, YT reencode and it seems clear to me that the rec.709 is used.It make sense in a way because computer color space is RGB 0-255 (or Rec.709 if you will).Videos are supposed to be seen on computer.
Also add the fact that YT compress the video a lot and dark scenes on the original file 9/10 times appear to be even darker as a result.

My guess is if you play with the luma (make it brighter to begin with) on your original file then maybe there is a chance to get a Rec-601-like (it'll never be true rec.601) but you might have something close to it. It's risky though but worth a try.

[Gavino]

It make sense in a way because computer color space is RGB 0-255 (or Rec.709 if you will). ... My guess is if you play with the luma (make it brighter to begin with) on your original file then maybe there is a chance to get a Rec-601-like

Both Rec.709 and Rec.601 use the same range of values - luma 16-235 and chroma 16-240, corresponding to RGB 0-255. The difference is in the mapping between RGB<->YUV. The two use different matrix coefficients, causing slight differences in color when converting YUV to RGB (as it must be for display, whether on a computer or a TV).

[themaster1]

My bad you're right, it's 16-235 rgb for both Rec 601&709