odd 4:4:4 output AVI > mpg audio sync probs at DVinfo.net

Stephen Armour · September 3rd, 2008, 08:07 AM

David, I'm trying to understand a strange behavior.

Outputting full 1920x1080p with 4:4:4 turned on, from Prospect 4K (latest), produces a lovely AVI. When viewed in Premiere CS3, the audio is dead-on synced.

However...if that same AVI is then converted with any program we've tried so far to a normal 16x9 progressive mpg for burning to a DVD, there are odd segments with 2-3 frames of video behind the audio. It is consistently in the same odd places, yet when viewed in Premiere, the original 4:4:4 AVI is absolutely dead-sync on!

When burned to a progressive 16x9 DVD, it is even worse and very noticable and absolutely not acceptable.

Very odd. I'm outputting right now as 4:2:2, as that is your recommendation (which I forgot when outputting the master AVI ...), but wondered if you have reports of this behavior from others?

I'll check it again with the 4:2:2 master when it's re-output to see if it is still a prob, but wondered if others have noted this behavior?

David Newman · September 3rd, 2008, 04:30 PM

Never heard of that one. Check the audio is other AVI tools like VirtualDub.

Stephen Armour · September 3rd, 2008, 09:57 PM

Switched to the highest bitrate I could safely force on CBR (tried every type of VBR, but it can't cut it) and it seemed to help a good bit. Since these are 25-30 min productions, it's no problem spacewise with that steady high data rate and makes for much smoother transitions and eliminates any MPEG blocking.

Audio still is a wee bit off at the same oddball places, but the video output is as nice as progressive 16x9 DVD's made from 1920x1080p can possibly get! Thanks CF, you definitely make us little guys look pretty good!

Now if we could just get something better than BR's measly 40Mbps, to take advantage of those nice 100Mbps CF AVI's...(besides outputting from HDD's like now)...we could REALLY look nice!

(BTW, David, Virtual dub did NOT like those problem mpg's and would not open them under any circumstances. It opened our big CF master AVI's just fine, and they were perfect. Go figure.)

September 3rd, 2008, 08:07 AM	#1
Stephen Armour Major Player Join Date: Dec 2005 Location: Natal, RN, Brasil Posts: 900	odd 4:4:4 output AVI > mpg audio sync probs David, I'm trying to understand a strange behavior. Outputting full 1920x1080p with 4:4:4 turned on, from Prospect 4K (latest), produces a lovely AVI. When viewed in Premiere CS3, the audio is dead-on synced. However...if that same AVI is then converted with any program we've tried so far to a normal 16x9 progressive mpg for burning to a DVD, there are odd segments with 2-3 frames of video behind the audio. It is consistently in the same odd places, yet when viewed in Premiere, the original 4:4:4 AVI is absolutely dead-sync on! When burned to a progressive 16x9 DVD, it is even worse and very noticable and absolutely not acceptable. Very odd. I'm outputting right now as 4:2:2, as that is your recommendation (which I forgot when outputting the master AVI ...), but wondered if you have reports of this behavior from others? I'll check it again with the 4:2:2 master when it's re-output to see if it is still a prob, but wondered if others have noted this behavior? __________________ http://lightinaction.org "All in the view of the LION"

September 3rd, 2008, 04:30 PM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Never heard of that one. Check the audio is other AVI tools like VirtualDub. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

September 3rd, 2008, 09:57 PM	#3
Stephen Armour Major Player Join Date: Dec 2005 Location: Natal, RN, Brasil Posts: 900	Switched to the highest bitrate I could safely force on CBR (tried every type of VBR, but it can't cut it) and it seemed to help a good bit. Since these are 25-30 min productions, it's no problem spacewise with that steady high data rate and makes for much smoother transitions and eliminates any MPEG blocking. Audio still is a wee bit off at the same oddball places, but the video output is as nice as progressive 16x9 DVD's made from 1920x1080p can possibly get! Thanks CF, you definitely make us little guys look pretty good! Now if we could just get something better than BR's measly 40Mbps, to take advantage of those nice 100Mbps CF AVI's...(besides outputting from HDD's like now)...we could REALLY look nice! (BTW, David, Virtual dub did NOT like those problem mpg's and would not open them under any circumstances. It opened our big CF master AVI's just fine, and they were perfect. Go figure.) __________________ http://lightinaction.org "All in the view of the LION"