I didn't want to hijack the thread at [Link: remotecentral.com], but it motivated me to ask these questions. Adjustments of this type always seem to be by the seat of the pants, which is not the way for us to do things!

I'd like someone who knows to describe types of lack of sync and even come out and state what is delayed and why. I've thought that audio might be delayed in an AVR, but video might be delayed if it enters an AVR as component and exits via HDMI; or processing in the TV might delay the video.

That all came up when I was asking myself "if you adjust sync using a test disc, does that mean it will be correct for all sources?" Heck, I've found it hard to perceive, when adjusting a receiver, whether it's the audio or the video that comes first when tings are out of sync.

What do you guys know about it?

If they provided a SMPTE track, it would be easier for us to see, but I suspect they basically do a purely electronic version of this for auto-synching AV receivers.

If you use a test disc, it wouldn't necessarily be correct for the rest, but I think each input can be adjusted, separately.

Use a video of a single drummer- it's easy to see and hear which comes first.

Typically the video processing of the display adds delay, meaning the sound comes before the matching picture. How much processing the display does can impact this too, for example some screens have a "game" mode specifically designed to reduce latency.

However, some sources and even content can have their own delays that might require permanent or temporary adjustment. So, while a "one adjustment should fix most" for between the receiver and screen (which is what the whole HDMI lipsync tech is supposed to do), you might still need adjustment between the source and receiver, and then if you get some poorly mastered content (this happens a fair bit with television) the user might desire access to a one-off adjustment.

As an example of a source issue, I've noticed that playing 23.976fps material from my XBMC Frodo system requires a -210ms delay to re-synchronize audio. My Dune player required a similar amount of delay, also only on 23.976fps material. So you might think that's an issue with running that framerate through my screen... but no! Because no delay is required when doing the same, through the same equipment, from a PS3!

Then there is DirecTV, with sync issues just on certain channels...