AVS HD 709 - Blu-ray & MP4 Calibration - Page 51

anyone know how to get the mp4 files over to windows media center? i want to get these up on the 360 so i can calibrate for my console. i downloaded the file but all i get is a bunch of spread out files once extracted. thanks in advance.

I have found a tool called vc1_info to check the REC709 flag on VC-1 titles. Of the 34 VC-1 HD discs I have checked, 26 are not flagged, including the new Spears and Munsil Blu-ray as well as both versions of DVE HD Basics. So, I think you're in good company in terms of flag setting.

They don't really say that in so many words. See below.

I believe the VC-1 specification states that if the Color Format Indicator Flag (COLOR_FORMAT_FLAG) is not set, then the color primaries, transfer characteristics and matrix coefficients are set to the default values. The default values are:

color primaries = BT.709
transfer characteristics = BT.709
matrix coefficients = BT.601

MPEG-2 and H.264 are much more wishy washy:

MPEG-2:

In the case that sequence_display_extension() is not present in the bitstream or colour_description is zero, the chromaticity is assumed to be implicitly defined by the application.

H.264:

When the colour_primaries syntax element is not present, the value of colour_primaries shall be inferred to be equal to 2 (the chromaticity is unspecified or is determined by the application).

I don't think there's any specification that explicitly says "if it's HD, REC709 should be used". It's more like "tribal knowledge".

Ron

Ron,

I am referring to the decoding standards for HDMI. They are quite explicit and based solely on resolution in the absence of a flag. See CEA-861-D for the HDMI 1.3 version.

I think the CEA folks were not satisfied with the tribal knowledge idea and decided to set the standard in stone (at least for HDMI).

For 480p, 480i, 576p, 576i, 240p, and 288p, "ITU-R BT.601-5 Section 3.5 (or CEA-770.2-C Section 3.3) shall be used for any color space conversion needed in the course of processing unless a different colorimetry is specified in the Auxiliary Video Information InfoFrame."

For 1080i, 1080p, and 720p, "ITU-R BT.709-5 Part 1, Section 4 (or CEA-770.3-C Sections 5.4-5.7) shall be used for any color space conversion needed in the course of processing unless a different colorimetry is specified in the AVI."

It think it may be better to just make one pattern that isn't flagged. That way, you can use that pattern to see what your device is doing with decoding and still decode the rest of the disc accurately (hopefully) for calibration purposes. If all of the patterns are decoded incorrectly because the flag is not set, then it pretty much renders the disc useless except as a way to check decoding.

Agreed. But you should also have a pattern with an unexpected matrix value to see if the decoder is even passing on the information at all.

Ron

Sure, but it's two different "flags". There's no direct way that the MPEG-2/H.264/VC-1 video bitstream matrix information can be sent to an HDMI controller. It has to go through a 3rd party, which is usually some host general purpose CPU (could be on the same SoC). And on that CPU is some software that has to read the matrix from the MPEG-2/H.264/VC-1 decoder, decide what the correct scheme is and then send that to the HDMI controller.

So if everything follows the specifications to the letter, then all those HD VC-1 titles you have should use the BT.601 matrix. That is, the host CPU should know that there's no matrix information in the bitstream, select BT.601 (as the VC-1 specification instructs) and then tell the HDMI controller to send a BT-601 AVI.

Ron

Ron,

Are you saying that the standards, even though they exist, are purposely ignored sometimes? I believe, for instance, that all HD-DVD players use REC709 coefficients for HD content, even for unflagged VC-1. Of the 26 VC-1 discs I have that are unflagged, 24 of them are HD-DVDs.

No, I'm saying it's implementation and application dependent. HD-DVD and Blu-ray over-ride the VC-1 specification and define that the HD matrix will be BT.709. It's probably pretty safe to say hardware Blu-ray and HD-DVD players will output BT.709 for HD content.

But the Popcorn Hour media player is not really a Blu-ray or HD-DVD player, is it? If you feed it some VC-1 Transport Stream or VC-1 in some other container, what "application" rule should it follow?

So in the end, you have to test the implementation on each player to make sure it's doing what you expect. Of course, that the role of test disks like AVS 709 (at least for the MP4 version).

Ron

In any case, the Popcorn Hour's behavior doesn't seem to follow tribal knowledge or any standard. I think the best solution for them would be to have its behavior controllable by the end user. This can be accomplished with a software switch or by sending YCrCb out of its HDMI port, after which you can set the conversion coefficients, gamma response, and color gamut in your display. All of the displays I work on have these controls.

What display lets the user choose either Rec601 or Rec709 as the conversion coefficients for HDMI?

Every projector I've ever worked on that has an HDMI port. These include:

InFocus IN72, IN74, IN76, IN78
Planar PD7010, PD7060, PD7170, PD8130, PD8150
Vidikron Vision Model 15
Runco RS440, VX8D

Eventually, all of the displays I have any say in will have this ability. Now that digital sources have become pretty good at moving the bits, one of the most annoying problems left is getting the color space right. If you use REC601 to convert content created using REC709 then you destroy the color balance of the display (no matter how well you've calibrated it), and it's not completely recoverable using any display side controls since some of the data is clipped in the color space conversion itself.

By the way, in addition to the manual control, all of the displays listed above have an auto setting that first looks at the AVI Infoframe, but then chooses based on resolution. REC601 is used for SDTV/EDTV resolutions, and REC709 is used for everything else.

I understand at one time there was a Calibration program listed here for people who didn't have a HD or BluRay DVD player. I would love to get my hands on it so I could burn it onto a DVD for our "Standard" DVD player. Anyone know where I can find it, we don't have a BluRay player yet and I would love to Calibrate our A850 LCD TV.
Thank You in advance..

Google GetGray

Like D-Nice, I have been quite happy using the GetGray disk.

Although I have not yet tried it, Tom Huffman offers a simple calibration disk with his article Basic Guide to Color Calibration using a CMS. You can find the links in the middle of the article.

Ahh, darn it's not free though, not a cheapskate but I plan on getting a BluRay player soon and will need a different calibrator then... Oh well, thanks D-Nice

When will we have test patterns for the wider color gamut standard?

Hello to all,

Any suggestions how to calibrate a new UE40B6000 LED LCD Samsung TV?

I can use a PS3 and I PC with an HD4870x2 via DVI/HDMI.

Just wanna know what shall I do, some simple steps will be much appreciated.

Kind regards.

THX Optimizer is included for free on many commercial titles. See http://thx.com/home/dvd/search.html

-Bill

See the Patterns document at the bottom of the first post.

-Bill

I found when using the THX optimizer on a DVD with composite video cabling that the color and tint test pattern was both blurry and very hard to use when compared to the AVSHD disc. Has anyone else noticed this or does using component video or hdmi make it much easier to use?

You mean standard definition is not as sharp as high definition, and HDMI is better than composite? I think other people have noticed that.

-Bill

Yes, but I'm asking if anyone else has found the color and tint pattern provided by THX not very easy to use, especially when compared to the flashing color bars on the AVSHD disc.

See:

http://www.avsforum.com/avs-vb/showt...5#post16309335

Ron

Thanks wmcclain but I realized my DVD is connected via Component cables which would do nothing for calibrating my Digtital box which is HDMI. No sense in calibrating DVD player since it will be replaced by a bluray player in the near future.

Hi everyone!
I'm a owner of a Samsung BR 2500 (european version).
With the new firmware 2.5 the AVSHD disc (many compliments to the authors) the 1.2 version doesn't works. Also with 24fps and so on...
The 1.0 version one can be read also with the newest firmware, so I ask you gently if it is possible to found and download (and where) this previous version.

Thanks a lot!

This may sound like a silly question...

but instead of using a color meter to measure the light coming from your HDTV, does anyone think it would be possible to use a digital camera in RAW mode or a webcam to take snap-shots of the test patterns displayed on an HDTV, convert the raw data into the format used by the HCFR color meter software, save it to a .chc file and then open the file in the HCFR color meter software?

I realize that a digital camera is made up of light sensitive cells (pixels) and that each one would probably receive a different amount of light, but if you only considered data coming from the center pixel? or the average color values of a group of pixels near the center?

I just thought that a digital camera works in much the same manner as a color meter, but a camera has lots of tiny light sensors (pixels) rather than just one like an actual color meter.

Anyway im probably missing something here so your comments would be much appreciated.

You would need a perfectly calibrated camera to do this.

OK, may be this has been asked but a quick search through didn't give me the answer. Anyway, with my PJ and BD player I have pretty much most of the bars flashing in the 'Contrast' setting, except may be four or five to the very right not visible, is this mornal, if not, what else shoudl I be aiming at? Many thanks.