Tyler Pruitt (Technical Evangelist for CalMAN) suggest that you will still need a calibration disk, as he posted to : Setting Contrast, Brightness and checking for Color Clipping, are considered as the initial and very important steps for any calibration. This means that you can't check your Dynamic Range with only AppleTV and MobileForge, you will need to AirPlay from iPhone or network of ATV some video patterns (no still pictures, no stuff from applications, no youtube) and then verify your Dynamic range, as the standard for Grade-1 say, you need to leave 'headroom' up to maximum bit level, so when you will look a Contrast Pattern (and a color clipping pattern) the bars should flash above 235 (it to 109% Super White) and not clip to 235 (so to flash only below 100% Reference White).įor example when you adjust for Brightness, the 1-16 Flashing Bars need to be invisible, if the user will add +5 to his TV Brightness control to be able to see 17 level (0.5% Gray) Flashing Bar, this adjustment may have lift his TV native black level, when a Brightness Pattern will be generated from an AppleTV, which will clip to 16 all 1-16 levels due to compression of levels) the user can apply an incorrect adjustment because 1-15 Flashing Bars will always be invisible.įor that reason, Contrast pattern generated from AppleTV (MobileForge) will not able to display 235-235 Flashing Bars which is required when you want to check for clipping and headroom (109% Super White) since after the compression all bars 235-254 will become 235. ![]() ![]() This automatically means that you can't check for Clipping with Peak White (which will require to generate patches for above 235, until 255 patterns) For that reason you see 1, because its already clipped due to conversion the ATV will do to output as I describe above. On the Apple TV menu, go to Settings > Audio & Video > HDMI Output > YCbCr.ĪppleTV has additional colorspace video output options, RGB-High and RGB-Low, but using any RGB selection, the incorrect conversion math of internal processing will increase even more the digital errors to the device video output.Īpple TV devices with proper settings can generate any combination for TV Video Legal (16-235), but they can't generate for TV Video Legal Extended (16-255). So while you send PC Level RGB triplets (0-255) at the output of AppleTV will be 16-235.īefore enabling the AirPlay Mirroring, the AppleTV video output must be set to YCbCr colorspace. When CalMAN will send command to generate 100% White 235.235.235 RGB Triplet to MobileForge App of iPhone, the iPhone will render it as 255.255.255 (RGB-Triplet) and AppleTV (with YCbCr output selected) will be compress to video levels 235.235.235 (RGB-Triplet) or 235.128.128 (YCbCr-Triplet). Whatever iPhone/iPad device which CalMAN's MobileForge is driving works in PC Levels, then each device converts to Video Levels when it pipes the generated pattern through the HDMI output. Since you are using CalMAN's MobileForge to generate patterns for a TV, you will need to setup CalMAN to work in Video Levels (16-235), then in the MobileForge tab (Middle Tab at the top of CalMAN) the 'Expand to PC Levels' box needs to be checked, because the video output will get compressed at the end. ![]() I will reply to some of your questions to clear up some stuff for better end calibration results for your setup.Ībout your AppleTV, to be able to output correctly the required patches, it will be required some settings from CalMAN and AppleTV.
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