I wonder if there is a simple solution for my problem:
I have a long theatre play recording, made with 2 cams.
I had already completed the multicam editing work, and when checking the result, I noticed that in the 2nd half of the sequence, one of the cams is slightly out of sync, probably because of 3 or 4 frames lost during recording or transcoding (AVCHD -> DNxHD). The source clips are 100% in sync at the IN point of the group clip.
Is there a simple way to shift all segments belonging to the offending cam by 3 or 4 frames, starting at the point where the problem is noticeable, without re-doing the complete edit work (hundreds of cuts...) ?
Hope I made myself clear :)
I don´t know of any way with the exception to relink to the origin ama linked media again and do a new transcode, what bothers me is that you are saying that he transcode process gets it out of sync, that should not happen, do you have any more specs to tell us .
Tomas
Looks like I was not clear enough sorry...
...when I said "transcode", I meant conversion from AVCHD to DNxHD using an external tool (FFMBC) - one of the source clips was fast imported (HDV), the other AMA-linked (MOV(DNxHD)), like I do very often - sorry for the confusion.....the problem may have been caused by the external transcoding or by one of the cameras - I haven't checked...(and not being in front of my editing PC, I can't check which source is missing frames (HDV or DnxHD)...anyway, trying to find the culprit may look useless at this point.)
So is relinking AMA a solution ?....the 3 or 4 frames lost somewhere in the middle of one of the source clips is a fact, I can't fix that; I'm just looking for a way to shift the segs belonging to the "faulty" source, now that editing is complete...
BenoitM: Looks like I was not clear enough sorry... ...when I said "transcode", I meant conversion from AVCHD to DNxHD using an external tool (FFMBC) -
...when I said "transcode", I meant conversion from AVCHD to DNxHD using an external tool (FFMBC) -
That might be one of your problems
BenoitM: Looks like I was not clear enough sorry... one of the source clips was fast imported (HDV)
one of the source clips was fast imported (HDV)
I am mixing avchd and hdv myself sometimes but I always use the capture tool to bring the media in
BenoitM: So is relinking AMA a solution ?
So is relinking AMA a solution ?
That is not possible with your current workflow, you should have started with ama linking initially and that to the origin media not using any middleman, sorry to be the one giving you bad news , I cannot see any way to fix this, maybe others have better ideas
mjolnarn: .... you should have started with ama linking initially and that to the origin media not using any middleman....
.... you should have started with ama linking initially and that to the origin media not using any middleman....
Wish I could do this; unfortunately, there is an open issue preventing me from using AMA with AVCHD in the first place: http://community.avid.com/forums/p/104606/636662.aspx#636662 ...waiting for a fix to streamline my workflow
Might be something with your cam or the ama drivers that your cams manufacturer are delivering, I am ama linking Sony media all the time without any level changes
edited .. and if you get level changes I think that this very easy could be fixed with either a CC adjustment in Avid or an adjustment in, for example Squeeze at a later stage , to experiment with third party encoders could be risky as you just have noticed
I've seen this too, and it has nothing to do with third party encoders, or AMA vs non AMA workflows, it's just that some cameras get quite hot (are You using a Canon by any chance?), when they reach a given temperature they begin dropping frames, resulting in progressively out of sync group clips (or autosync clips for that matter): the clip will be out of sync by 1-2 frames on the first drop, increasing the number of frames drop after drop, so I'm afraid that You will have to eye check every single cut and adjust as needed by parking the blue line over the offending clips and using the slip keys (soon after the M key if I recall), it's a monkey job, I know, but it's fast and easy...
peace luca
luca.mg:You will have to eye check every single cut and adjust as needed by parking the blue line over the offending clips and using the slip keys (soon after the M key if I recall), it's a monkey job, I know, but it's fast and easy...
Just tried another method, that looks complex, but may be faster than yours, Luca:
created a new group clip (say grp#2) with correct sync points for the part that has drifted camera clip (fortunately, for this live recording, I made a flash at the start AND at the end of the show, so I can easily make two versions of the group clip, one with the first flash, one with the ending one)
sent this grp#2 clip to a new sequence (seq#2) on V1/A1-2
create a new set of V and A tracks (V2/A3-4)
load the first sequence "seq"1" (the one that uses grp#1 and is correctly sync'ed to about the middle of the play) in the source monitor
mark the OUT point on both the source monitor (containing seq#1) and the timeline (containing seq#2 on V1/A1-2) at the ending flash, set the IN point for the timeline at a point where the drift becomes noticeable in the original edited T/L.
send (Overwrite) the source (seq#1) to the T/L using this 3-point edit using V2/A3-4; we now have on V1/A1-2 the corrected grp#2 source clip without any edits and on V2/A3-4 the grp#1 clip with "drifted segs", but with all the edits (camera cuts) already made.
Activate track V1 and deactivate V2 (and A1-4); turn on multicam mode
at this point, the monkey job is: park the blue line at each existing edit of V2 (CTRL-click makes exact alignment easy) then click on the desired frame in the quad-split monitor; this makes the same edit on V1: in a matter of minutes, I have "cloned" all the existing camera cuts on V2 to V1
Very good. As usual there's always more than one way to achieve a goal. Ganging the tail sync group and the sequence to be fixed could have been a third option for example, if I only knew that You had a end sync point, but I'm sure that others may come out with different solutions, whichever way, it's a monkey job, nice to have a trusty assistant to do it! Is the show shot on Canon?
Cam1 was CANON XH-A1s (no longer using tapes, HDV(m2t) recorded with external flash recorder, files successfully stitched together with simple binary joiner, then error-free fast-imported in Sy6), cam2 was CANON HF-G10 (AVCHD source files successfully stitched together with the Canon-provided tool, then 100% error-free transcoded to DNxHD120 using FFMBC 0.6)
I successfully used this workflow for tens of theatre plays in the past year...(often with a 3rd cam, a Sony Z5 also tapeless)
Actually, at the end of the recording, it is cam2 that was behind cam1, but since I use Cam1 as audio master, I doubt there were any lost frames there: 3 frames = 1/8 s, that doesn't happen unnoticed in audio, particularly when comparing this audio waveform to the one recorded separately in 4 track PCM from the mixing console to a PC using Steinberg: not the slightest drift there...And 3 added frames for the stream coming from cam2 looks pretty unlikely....Remains the possibility that the drift appeared gradually (due to camcorder clock differences), but again, such a "large" drift between my cameras (3 frames in 75 minutes), while possible (consumer grade camcorders, no genlock), never happened to me in the past...perhaps the temperature in the theatre was different that night, etc...who knows...So the cause of the "drift" remains a mystery, and since I worked around the problem now, I won't spend time making extensive research but jump to my next play to edit .
Thanks for all the suggestions !
Another possible method would have to go on the edited multicam timeline and place the blue line on the faulty clips, on at a time, and Slip Edit by pressing the < or > key 3 or 4 times.
Sylvain Primeau
Self-employed worker - Les productions Primeau Medias
primeaumedias.com
Radio-Canada/CBC news editor
cbc.ca / ici.radio-canada.ca
BenoitM: And 3 added frames for the stream coming from cam2 looks pretty unlikely....Remains the possibility that the drift appeared gradually (due to camcorder clock differences), but again, such a "large" drift between my cameras (3 frames in 75 minutes), while possible (consumer grade camcorders, no genlock), never happened to me in the past
And 3 added frames for the stream coming from cam2 looks pretty unlikely....Remains the possibility that the drift appeared gradually (due to camcorder clock differences), but again, such a "large" drift between my cameras (3 frames in 75 minutes), while possible (consumer grade camcorders, no genlock), never happened to me in the past
FWIW, I've noticed my cameras tend to drift about 1 frame every 20-30 minutes when doing unlocked separate-system audio, so maybe clocks just aren't yet as accurate as we'd like them to be.
NetHead:FWIW, I've noticed my cameras tend to drift about 1 frame every 20-30 minutes when doing unlocked separate-system audio, so maybe clocks just aren't yet as accurate as we'd like them to be.
True, especially when using consumer-grade camcorders....
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