AVS HD 709 - Blu-ray & MP4 Calibration - Page 67

The video clips are intended to be standard video levels. Generally this is stated as 16-235, but the levels actually range from 1-254. In video 16 is intended as black and with a computer signal 0 is black.


If you want to be able to see 235-254 is debatable, but generally you don't want to be able to see 1-16 with your final settings. If the display is set based on the input signal there is usually more than enough range to set brightness too low, but I'm not familiar with the projector to comment further.


I'm again not familiar with either the Nvidia or CoreAVC settings, but I'll assume that you are preserving the video (16-235) levels within the computer output. In such a case the display should probably be set to expect video levels (if possible), rather than computer levels. Setting the display to expect video levels will cause the loss of the computer information for 1-16, meaning that normal computer levels will be too dark. On the other hand setting the display to expect computer levels will probably mean that you might not be able to lower brightness enough for video black to be the darkest level on-screen, which seemed to be what you said previously. Another way to handle things would be to expand the video so that it is output as computer levels.

I'm not familiar with the program. I think the AVCHD has 44 playlists to match the number of video clips. The title numbers are in the PDF, but the AVCHD has a rather simple order. For example basic settings, title 1, should be clip 0. I believe everything on the AVCHD is arranged like that, so that the clips and playlist numbers are just the title number minus 1.

For a more complex layout like the HDMV, the navigation can be followed with BDedit from http://forum.doom9.org/showthread.php?t=125903 In BDedit the title numbers listed in the PDF are the numbers that appear under index.bdmv. Say for example you wanted to know which clip was played by title 44. You would choose 44 in the index.bdmv list. Then you would look for "Play PL #" under MovieObject.bdmv at the right. When you click on the Play PL line it would take you to the playlist for that title number, and the video name is listed in the playlist area.

In the flat screen area there is probably a thread for your display. If you don't have the means to measure the display yourself, you could see if there is an average setting reported from people that have measured the display. I'm somewhat assuming here that the displays don't vary too much, which may or may not be the case depending on brand and model.

I am not familiar with the display, and you don't list the player. The player or display could cause clipping of the near blacks.

The primary purpose of the brightness control is to set where the image begins increasing in brightness. You want black from the video to be the absolute darkest part of the image, and that's mainly what brightness is meant to set. If you adjust the brightness control too high then video black is lighter than it could be. The main downside of setting brightness too high is that you reduce the TV's available contrast, and dark scenes will not be as dark as they could be.

On many LCDs there are more controls than just brightness and contrast that will affect the light output of the TV. Some LCDs offer backlight controls that allow for a brighter image, but I don't know what the LED TVs offer in this area. A few TVs offer an adjustable gamma, and by altering gamma that could also affect light output in the middle-grayscale somewhat similar to increasing brightness. In the CNET review they do mention gamma increasing near black, but still I would think the TV could generally have brightness set no higher than maybe the sort of range the APL Clipping Pattern might suggest.

It's also possible that levels could be changing somewhere, but without anything else to go on I have to assume the above quote is just a subjective impression. The easiest way to check HD video levels is probably by comparison against known levels, for example comparing a very dark video against say RGB 0 or 16. I checked my computer and I didn't see see any variation between the Patched version and DVE Basics on TMT3. Of course on my setup I can't see below black or above white without changing Avivo Video settings, or possibly TMT3 settings. As far as what your video card and drivers are doing, http://www.avsforum.com/avs-vb/showthread.php?t=1179134 would have far better feedback than I could.

When my ATI card was still fairly new the drivers had some issues, and it took a number of months before they were sorted out. Assuming levels do match between Windows Media Center and TMT, you could try setting brightness by playing the MP4 version in WMC. So far I have not yet ran across a clear example of a player that displayed the versions here much differently than commercial Blu-rays, but if you have happened to run across one then Digital Video Essentials HD Basics would be a better reference for setting brightness. If you use Netflix they should have the disc.