It only allows a TV to tell an AV receiver two delay values: one for progressive video and one for interlaced video. The HDMI automatic lip-sync correction feature(TM) you mentioned is widely misunderstood. Mine have varied over 100 ms from one TV program to another!īut I still think there would be demand for a device to measure the delay even if it only gets you close. And it won't help at all for broadcasts since they vary so much from program to program. Preferably within 1/3 ms if possible.īut as a practical matter measuring and calibrating an AV receiver's delay (or Felston delay) to match a test disc (DVD or Blu Ray) that has perfect sync will be perfect for "that disc" but only get you in the ballpark for other discs unless they alos have perfect sync (and most don't). However, it would need to be acurate within + or - one ms at least. Is that the device discussed here? (An evolved version perhaps?) I watched the YouTube video that linked to this post and that device seemed to be watching a mid screen black to white transition and numerical delays were being displayed on screen. But even as it is, you can get it to work. The issues with the prototype are small - the adjustment pots are a bit sensitive, the mic is facing the wrong way and you need a quiet room with the volume up loud. Red, red/green, green (sync within 5 ms), green/yellow, yellow. Then you put it into test mode, and it tells you which way you need to adjust your audio delay (on your amp or processor or Felstron). Interestingly, you can calibrate quite accurately just by looking at 2 flashing LEDs. You put it into calibrate mode, and adjust it until the "light" LED flashes with the pulses on screen, and the "sound" LED flashes with the beep. The device has a light sensor, and microphone. Put on a beep and flash test DVD or transmission. If this is the heaven sent device you have been waiting for for years, please could you post here. Would anyone else be interested in this, or am I on my own here? He is trying to decide whether to open-source, or supply as a kit. The end result is spot-on lip sync (and I know HDMI is meant to fix all of this, but it doesn't!). A lot simpler and cheaper than buying a 2 channel oscilloscope and building the test probe. But watching video material, any inaccuracy is easy to see and annoying.Īfter explaining this to a friend, he built me a prototype a/v delay tester. I find that the ear/eye connection in the brain is not that good at determining before/after when the delay is getting close to correct. Mark HodgkinsonTHX & ISF Level II Certified Calibrator,24 Hatton Street,Macclesfield,Cheshire,SK11 6RZ.One thing that frustrates me is how to accurately measure lip sync, to set the audio delay in my amp.
The Spears and Munsil calibration disc (and if you have not got it yet, you should be getting the second edition, which has recently been released - I have the first edition) is certainly helpful in setting brightness, contrast and colour, but without a calibration meter and software you cannot set the greyscale and colour management systems correctly, which is where a professional calibrator comes in!
You may also want to consider a gentleman named Gordon Fraser of Convergent (I'm afraid I have no link for him) and a colleague of Stephen Withers's, Mark Hodgkinson, details below. Julian Scott of Display Calibration and Stephen Withers of StormFront have done most of the calibrations of people on this forum recently, including mine. Paddyfin, bigboss has done well to give you those links, but I seem to remember somebody saying on the Calibration thread that they had tried to contact chromapure, and got little or no response, but maybe you will have better luck. MODERATORS - perhaps you could please move this thread from the Home cinema section to the "TVs and Projectors" section, please?