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[Nyal Mellor]

I have around 120ms of delay between audio and video. I set the AV sync setting to 120 and things seem aligned.

I wonder though where this delay is coming in? It doesn't appear when I play back via TMT.

I do have a test pattern for AV sync on blu-ray but I don't know how I can get it to play on JRiver as it's buried in a calibration discs menu tree. Any idea?

[Matt]

Your audio hardware could add latency that isn't accounted for (USB buffers, for example) or your display could have lag.

If you describe your hardware in a little more detail, we might be able to venture some guesses or even figure out ways to reduce the latency a little.

To calibrate, this test clip works pretty well:
http://files.jriver.com/accessories/test_clips/audio_sync_test_25hz.vob

[Nyal Mellor]

The video chain is HTPC Mobo integrated HDMI (Intel) --> Lumagen --> Projector

The audio chain is Lynx AES16e --> Metric Halo LIO8

The Lynx has a buffer, at present it is set to 1024 samples...as far as I know this means about 20ms with 48K content (1/48000 * 1024).

As to what is adding the other delay I don't know.

I played back a Disney AV sync test via TMT and as far as I could interpret it said there was no delay (!). Maybe TMT is not using ASIO, I am not sure of the inner workings of these things. In any event the Lynx AES16e buffer doesn't seem as much as the delay I'm getting which is basically equivalent to 3 video frames.

[Matt]

It's not too surprising if the A/V sync in TMT is different -- it probably doesn't use ASIO, madVR, etc.

The Lynx AES16e won't have much delay.  The Lynx USB products have a second USB buffer size you can set to reduce latency, but I don't think that applies to internal cards.

The Lumagen and projector both probably add a little lag.  For example, my Epson projector adds like 3 frames by itself

As a side note, it would be interesting to test the quality you get using madVR and no Lumagen.  In other words, do all the processing with a computer, like you're doing for audio.

[Nyal Mellor]

What processing does MadVR do? I know with the Lumagen I can do greyscale adjustments and have full control of color points and even color point luminance.

The AV sync is definitely strange. Sometimes if I pause a movie and then restart the sync changes. I guess something is filling a buffer. I will experiment with the Lynx settings and report back.

I don't believe it's to do with the video chain post HTPC as like I said I don't have it with TMT and I also don't have it with Red October standard.

[Matt]

madVR does high-quality scaling, optional color correction, exclusive output to reduce jitter, nicer VideoClock integration, etc.

Lots more details (maybe more than you want!) here:
http://forum.doom9.org/showthread.php?t=146228