AVS HD 709 - Blu-ray & MP4 Calibration - Page 77

HD Nation did a 4-segment HDTV Calibration series that demonstrates how to set basic user controls. The first segment is in http://revision3.com/hdnation/hdcalibration#rev3Player and it continues in episodes 57-59. On an upcoming revision the video segments will be included for new users in the AVCHD and HDMV downloads, but the same video can be currently viewed at HD Nation.

There is an item in Misc Patterns for a general 2.35:1 screen height check. I think I used 818 pixels, but the movies I looked at that were marked 2.35:1 did not appear to use the same number of vertical pixels. The version in http://www.avsforum.com/avs-vb/showt...1#post19224071 has more items to check geometry.

The Xbox only played HD DVD with an extra accessory, so it will not work.

I'll expect the newest Xbox model works similar to the prior models and requires an online update to play the MP4 encode. Did you have the Xbox connected to the internet when you tried to play the DVD with the MP4 video fies? I'll assume that you decompressed the download before buring to the dvd.

http://www.avsforum.com/avs-vb/showt...1#post19224071 is a newer and hopefully more useful mp4 encode, but it also requires decompression and will likely also need the player to be connected to the internet to play the first time.

Generally the newer MP4 version makes more sense for most applications.

I know it's possible to share internet from a laptop, but most laptop do not have connections to display an external source. Most likely you will need some other display.

When you play the video and use the meter, you are measuring how your electronics deal with HD MP4 video from that source. So in the example, you would know how your Xbox performs with HD MP4 video on that TV input. There are basically three variables in the example: the source (Xbox), the display (TV), and the input (Component?). If you change any of the three variables you may possibly change how your electronics deal with the HD MP4 video. So if you swapped out the source, changing the Xbox for a Blu-ray player, that could possibly change the measurements even if the TV and input remained the same. The main idea here is that the measurements are specific to the source and input, and changing the source (video player) or input (component, HDMI, VGA) could possibly affect the measurements.

Generally the simplest thing to do is to start by calibrating for a source that you will be watching most often. Personally I mainly watch Blu-rays, so I measure either the HDMV or AVCHD from my Blu-ray player. That way I have a good idea how my Blu-ray player and TV deal with HD video on that HDMI input. From the measurements I know how my most often used source (Blu-ray player) works with HD MP4 video on the display (TV) for that input (HDMI). By using the HDMV or AVCHD on my Blu-ray player I don't necessarily know how another source, like an Xbox, would play HD MP4 video.

Note: When I have calibrated for each of my sources it happens that they are all very similar and can use the same display settings, but there are too many variables to simply expect this sort of behavior.

I could change the current border to 9 pixels and label the inside 2.4:1, but I don't know how "cross hatch pattern with diagonals" is different than the linked mp4 version. I am not familiar with front projection setup, so any comments in that direction have to be very specific. Attached is an image of the current pattern that could be modified to indicate any changes besides the 2.4:1 note. I am almost done with the new menu layout, and once that happens I don't have any plans for any further revisions.

 

cinema5.zip 129.080078125k . file

The first three patterns from http://www.pbase.com/jackcnd/convergence will be included in the non-MP4 versions. Between those patterns and the two grids that are included in v1.3, I think that should be enough items for convergence. From my own convergence adjustments I'm not sure diagonal lines would be any help. I did a modification of the current image to see what white on black would look like, and I'm not sure it would be any improvement over the current version if the primary idea is aligning two images.

Someone can correct me if I'm wrong, but mediainfo reported all the movies I looked at as 1920x1080 regardless of how the video is noted on the back of the box. Based on information such as http://forum.doom9.org/showthread.php?t=154533 I'm not sure how the video would be encoded any other way for Blu-ray. Currently I don't know of any issue with using 1080p video for the pattern.

Here is the same pattern with some modifications. If white lines will work better then it's a reasonable change. If this works I'd probably just note the image heights in the PDF rather than placing text on the image.

 

cinema6.zip 134.298828125k . file

The outside of the line is 818 pixels and the inside is 800 pixels.

I haven't found a reliable way to estimate disk and download sizes, but it's looking like the next version may get close to filling a single-layer DVD. Currently the plan is to only include the last pattern named cinema6 in the final release.

The numbers shown on the Black Clipping Pattern are the luma values that are really used for the video encoding. The percentages shown are just an approximation of those luma values. This item has been changed for the next release scheduled for the end of the month. The note for the future release is below.

Grayscale from 5% to 50% was moved one digital level lower to match with Digital Video Essentials HD Basics. This makes the grayscale steps equal, in terms of the digital luma values, except for the first step above black. Previously the uncommon step had been near the middle of the grayscale, instead of above black. This item is primarily related to rounding from the digital luma values to the percentages shown on-screen, but more details from the previous known issue can be found in this comparison or these measurements.


There are a few dark-gray levels that DVE doesn't show. I think the first luma level above black on the DVE pattern is 20, and I think AVIA uses 19. If you are trying to get black as dark as possible in a dim room the DVE pattern may allow for clipping a few levels above black (17-19 if 20 is correct). The PDF description for APL Clipping Pattern is intended to take room lighting more into account than the PDF description for Black Clipping Pattern. Again the PDF description may change for the next release. For most digital displays, I would suggest the following:

1) Find where 17 clips by using the Black Clipping Pattern. You can do this in a dark room right up next to the display to negate room lighting. I would suggest not setting brightness darker than this setting.

2) In typical room lighting at a usual viewing location find if you need to increase brightness with the APL Clipping Pattern. As long as you can see 19 to 20 flash in these conditions the setting should generally match with the commercial patterns.