|
Avid Pro Audio CommunityHow to Join & Post • Community Terms of Use • Help Us Help YouKnowledge Base Search • Community Search • Learn & Support |
#1
|
|||
|
|||
VTR Jog Response & QC
Hi all,
Been doing a lot of layback to tape lately and have had some tapes rejected by QC for audio sync issues. QC claims 4-5 frames late across the board for the entire 90 minute feature. Everything looks great when you play at normal speed, but our QC folks don't seem to care about that. They pick a couple of spots and using the VTRs remote controller, jog the tape back and forth frame by frame. When I do it myself, it seems like the slower I jog, the worse the sync. Is this even a valid test? It seems like the deck would have a tough time keeping up with this in a frame accurate way. These are dubbed language versions so lip sync isn't really a good test so mostly sound effects are checked. To make matters worse, the QC'ers picked some spots where the actual visual event (that creates the sound) isn't even clearly visible! Any advice on dealing with this? I told them to trust their eyes & ears but was told "this is the way we do it"... Any advice would be greatly appredciated! Cheers, Tom
__________________
Yesterday, I cudn't evun spell injunear. Now I are one! |
#2
|
|||
|
|||
Re: VTR Jog Response & QC
Hi Tom
What tape format are you laying back to? Pete |
#3
|
|||
|
|||
Re: VTR Jog Response & QC
We're laying back to a variety of tape formats: Sony HDCAM SR, Digibeta (on DVW-500 & MVW-2000), D5, NTSC & PAL. Seems like the "problem" tapes are Digibeta, I don't remember having any SRs rejected.
I still feel that, regardless of the tape format or particular deck being used, jogging the deck to a still frame and listening to the audio stutter while the deck tries to play 1 frame of video and 1 frame of audio isn't a valid way to verify sync. I do think that the variety of tape formats and decks will make that process, however accurate or inaccurate it may be, return inconsistent results. Which, in my mind, makes the test invalid.
__________________
Yesterday, I cudn't evun spell injunear. Now I are one! |
#4
|
|||
|
|||
Re: VTR Jog Response & QC
Those decks are designed to scrub slowly IN SYNC. In other words, when the mode is set for audio to play continuously during scrub, and you scrub very slowly, you can clearly hear which frame an impact sound occurs on. The image will show the same frame as the one you are hearing (looped repeatedly in an annoying way, but you can hear it). This performance can usually be verified where bars/tone have been edited on. The tone will start on precisely the first visual frame. If a count down is included, you can have them check that.
|
#5
|
|||
|
|||
Re: VTR Jog Response & QC
If that's true for the SRW-5500 and the AJ-HD3700B, could you share how to configure that? I find scrubbing for purposes of checking sync with the AJ-HD3700B to be extremely difficult.
__________________
Jonathan S. Abrams, CEA, CEV, CBNT Apple Certified - Technical Coordinator (v10.5), Support Professional (v10.6 through v10.10) |
#6
|
|||
|
|||
Re: VTR Jog Response & QC
Quote:
I've really begun to mistrust scrubbing tape to confirm audio sync after a couple of recent experiences; In one case, a Digibeta tape was kicked back for a dropped in section at the end being one to two frames late. Later, the same tape was checked again, this time the same section was supposedly 10 frames late. The tape had not been modified! The only difference was the QC tech and that the first test was done on an SRW-5000 and the second on a DVW-A500. The other case was after I'd layed back a fix for one of these tapes, I was using the remote serial controller that the QC techs use to scrub the tape and check sync. I found that I could fairly easily get the sound to play up to a frame and a half early or late when jogging back and forth and then down to a still frame (with stuttering audio) as the QC techs do. On top of everything else, the QC techs are using a flat panel (supposedly delay compensated) while I'm using a CRT... Cheers, Tom
__________________
Yesterday, I cudn't evun spell injunear. Now I are one! |
#7
|
||||||
|
||||||
Re: VTR Jog Response & QC
Quote:
Ping me outside of the DUC with what the menu settings are on the DVW-A500 you are using. We have never had a problem with checking audio sync using the jog wheel on a DVW-A500. Quote:
Quote:
Quote:
Quote:
Quote:
__________________
Jonathan S. Abrams, CEA, CEV, CBNT Apple Certified - Technical Coordinator (v10.5), Support Professional (v10.6 through v10.10) |
#8
|
|||
|
|||
Re: VTR Jog Response & QC
Quote:
Quote:
added: The timecode reader display may not always be perfect. When I say near-perfect scrub, I mean that when scrubbing across a hard cut, like from black to first frame of bars/tone, there is no uncertainty that audio and video are scrubbing on the same frame at the same time. Last edited by Postman; 09-23-2008 at 05:53 AM. Reason: added thought |
#9
|
|||
|
|||
Re: VTR Jog Response & QC
Quote:
Anyway, like it or not, I've got to learn to deal with this since I'm sure the QC group will continue to do things the same way...
__________________
Yesterday, I cudn't evun spell injunear. Now I are one! |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
In Response to the Response to Pro Tools HD 10 Feedback... | Dism | Pro Tools 10 | 31 | 10-29-2011 06:11 AM |
slow response | tonwurm | Pro Tools TDM Systems (Mac) | 12 | 12-18-2008 05:56 PM |
No response | tgod | General Discussion | 6 | 02-06-2007 08:45 AM |
Flat response? | optymusblu | 003, Mbox 2, Digi 002, original Mbox, Digi 001 (Win) | 4 | 07-05-2003 10:59 PM |
HD & system response | Will Russell | Pro Tools TDM Systems (Mac) | 29 | 06-09-2002 07:25 PM |