Blackmagic capture sync problems at DVinfo.net

Ian Lewis · November 5th, 2010, 02:12 PM

I haven't done this for a while but it used to work before...

Capturing HDCAM via BM Decklink to CF Neo4K, sound and picture drift out of sync very quickly - picture ahead. When I've done this in the past I had no trouble, but that was over a year ago and there've been software updates and changes since. Capturing uncompressed to BM avi is absolutely fine.

HDCAM 1080/25p from a JH3 deck via HD/SDI to Win7 64 using Cineform HDlink. Neo 5.1.4.273 - I had the latest Beta installed and had the problem so rolled back but no difference...

anyone have any ideas? I have a lot of rushes to get on disk, so capturing uncompressed and converting isn't an option.

Thanks

David Newman · November 5th, 2010, 06:44 PM

Reinstall the beta, as it has been revised twice, and is likely done. Then capture a sequence with good sync markers and smooth motion (like a metronome if you have one.) Then you can determine what your issue is. What I reject is it is "drifting" out of sync (it is hardware clock locked,) but it might be dropping frames or marking the headers with the wrong speeds. With a known source you can look for missing frames, and calculate the percent difference, which can be to determine which is happening on your system. Picture ahead likely means drop frames, but you need to confirm. Once we know what the issue is as we should be able to work out the issue.

November 5th, 2010, 02:12 PM	#1
Ian Lewis Regular Crew Join Date: Mar 2008 Location: Farnham, UK Posts: 87	Blackmagic capture sync problems I haven't done this for a while but it used to work before... Capturing HDCAM via BM Decklink to CF Neo4K, sound and picture drift out of sync very quickly - picture ahead. When I've done this in the past I had no trouble, but that was over a year ago and there've been software updates and changes since. Capturing uncompressed to BM avi is absolutely fine. HDCAM 1080/25p from a JH3 deck via HD/SDI to Win7 64 using Cineform HDlink. Neo 5.1.4.273 - I had the latest Beta installed and had the problem so rolled back but no difference... anyone have any ideas? I have a lot of rushes to get on disk, so capturing uncompressed and converting isn't an option. Thanks

November 5th, 2010, 06:44 PM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Reinstall the beta, as it has been revised twice, and is likely done. Then capture a sequence with good sync markers and smooth motion (like a metronome if you have one.) Then you can determine what your issue is. What I reject is it is "drifting" out of sync (it is hardware clock locked,) but it might be dropping frames or marking the headers with the wrong speeds. With a known source you can look for missing frames, and calculate the percent difference, which can be to determine which is happening on your system. Picture ahead likely means drop frames, but you need to confirm. Once we know what the issue is as we should be able to work out the issue. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman