AJA Video Systems Forum
AJA IO Express Downconvert delays video 1 frame
AJA IO Express Downconvert delays video 1 frame
by Trevor Asquerthian on Nov 24, 2010 at 11:55:07 am

Testing out a new IO Express (although it looks like it was on the shelf for a while judging by the date of the firmware) - updated to latest firmware and running v8 drivers.

Outputting SDI (with embedded audio) to Decklink SD card.

Output of 625 10 bit uncompressed captures in sync.

Output of 1080i (DVCProHD and ProRes422) downconverted to 625i result in audio that is consistenly 1 frame in advance of the pictures. I presume this is the downconvert process taking place within the IO Express box?

Any way of delaying audio to match (other than sliding it on timeline)?


Re: AJA IO Express Downconvert delays video 1 frame
by Donal O Kane on Nov 24, 2010 at 12:36:13 pm

It is annoying and must be because of the downconvert but I have found that the most reliable way to sort this out is to copy the sequence and slide the timeline 1 frame.

I have delivered about HD 20 programs on Digi this way and it gets them frame accurate every time when I slide on the timeline.

It's not pretty or how it should work but it works.
If you do find a way you post it up!


Re: AJA IO Express Downconvert delays video 1 frame
by Trevor Asquerthian on Nov 24, 2010 at 12:49:08 pm

I've also discovered that I get green flashes when downconverting a ProRes422 timeline.







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