This IS the Avid L2: Re: [Avid-L2] Exception: SMReturnTapeMobOffset: sourceMob editrate (24) does not match tc editrate (30). ?

Wednesday, February 4, 2015

Re: [Avid-L2] Exception: SMReturnTapeMobOffset: sourceMob editrate (24) does not match tc editrate (30). ?

I know when there are separate .thm files I see those appear in the QT change list. If there are not separate .thm files what is the indication that there is embedded .thm data? I haven't noticed that but I had been under the assumption that .thm data only came in the separate files.

---In avid-l2@yahoogroups.com, <bouke@...> wrote :

'some' Canon material has the THM embedded.

I know for sure this is the case on 60D material.

No worries, on loading the clips QTchange will tell you if THM is found, no matter if you see them or not.

hth

Bouke

VideoToolShed
van Oldenbarneveltstraat 33
6512 AS NIJMEGEN, the Netherlands
+31 24 3553311

----- Original Message -----
From: bigfish@... [Avid-L2]
To: Avid-L2@yahoogroups.com
Sent: Tuesday, February 03, 2015 7:57 PM
Subject: Re: [Avid-L2] Exception: SMReturnTapeMobOffset: sourceMob editrate (24) does not match tc editrate (30). ?

I got a chance to talk with the camera folks last night and I asked them why some of the Canon 5D Mark 2 media folders had .thm folders and some didn't. They weren't sure why they differed between the cameras they had used but they say they will research and get back to me. Now they are shooting with Canon 5D Mark 3 which has a form of time code based on the camera's time of day clock. That gets embedded in the .mov clips is what the camera operator said. From your post it sounds like sometimes even if I don't see .thm files in the folder with the .mov clips there still may be .thm data embedded in the .mov file itself. Can you elaborate on this as I was under the impression I had to actually see the .thm files for that function of QT change to work.

---In avid-l2@yahoogroups.com, <bigfish@...> wrote :

I checked the original clips vs. those processed in QT change and the originals don't show a TC track in QT Pro 7 or in Mediainfo. The QT change processed clips do show a TC track in QT 7 and Mediainfo. And both sets of clips are shown to be 23.976 in Mediainfo and 23.98 in QT 7. The mediainfo screen grabs show the comparison.

I'm beginning to wonder if there is any interaction with what project format is set to when the original ama link is done. If the project is in NTSC 23.976 project and you ama link to a 23.976 .mov I wonder if Avid starts to think of the .mov like it would a 29.97 tape source and decides under the hood the base time code TC 1 is 30 frame based? I've posted recently where we have speed ramp issues with 23.976 clips that get converted in the final uprez but get shifted from the original frames kind of like a 24 frame vs 30 frame time code recalculation in the motion effect. Today the AE is going to regroup the problem clip and see if it then plays nice in the group when scrubbing throu gh.

---In avid-l2@yahoogroups.com, <bouke@...> wrote :

John,
Mr.QTchange himself here.
Few points:
I suspect the faulty clip has indeed NTSC TC.
Do note, QTchange lets you do all kind of stuff, no matter if there is logic
or not! Perhaps those clips were also processed by QTchange?
(And further processed. Not sure what versions of Avid, but in my experience
Avid eats any TC FPS, just uses the first number as a start.)

Easy to check. Open in QT player 7, switch on TC (right click on the counter
display if it's not enabled in the setup, and select TC).
Now see if you have frame 25 and higher if you step by frame.
If so, use QTchange to alter the TC FPS rate. Just set QTchange to 23.976,
load clips and do a 'refresh TC'

Tape names:
AFAIK, Avid has NEVER honoured QT TC reelnames.
This is why QTchange has an ALE export function to do a merge with sources.
I take it the AE is doing the 'modify source' dance, and set a Reelname when
the error pops up?

Now for the THM files.
60D does have THM files, but they are embedded in the clips. If you have
QTchange set up to use THM, you still will see 'thm found' in the file
list.

As for the FPS confusion, Avids notation of 23.976 may be 24
Apple talks about 23.98. This is plain stupid IMHO. The math is easy: 24 *
1000 / 1001 = 23.9760
(If you ever need to do math on fps conversion, you want to calculate with
the right numbers.
On a one hour show, the difference between 23.98 and 23.976 IS siginficant.)

hth,

Bouke

VideoToolShed
van Oldenbarneveltstraat 33
6512 AS NIJMEGEN, the Netherlands
+31 24 3553311
----- Original Message -----
From: John Moore bigfish@... [Avid-L2]
To: Avid L2
Sent: Tuesday, February 03, 2015 2:51 AM
Subject: [Avid-L2] Exception: SMReturnTapeMobOffset: sourceMob editrate (24)
does not match tc editrate (30). ? [1 Attachment]

On of our AEs is having some problems with some Canon 5D footage.
Apparently production shot with varying models of 5D some with time code and
some without. I used QT change to add time code based on the .thm folders
from some of the cameras. Other cameras did not have a .thm folder with
their media. Is that typical of earlier Canon 5D models or other Canon
models or is that a setting in the camera to include .thm or not?

I didn't add time code to one camera that had already been transcoded in
Avid 5.5.x on a mac. According to the AE this camera once grouped behaved
strangely and while scrubbing through the group it would jump to video from
earlier in the clip etc... Also typically they have found that in order to
add a tape name to Canon 23.98 footage they have to ama link in HD 1080P
23.98 project and add the tape name then they can switch project format to
NTSC 23.98 project and transcode to offline media 14:1. For this particular
clip it works just the opposite and they have to toggle to SD mode to add a
tape name but still the clip gives the aforementioned weirdness when
grouped.

Because of the problem the AE was having I went back and also added time
code using QT change. There was no .thm so I just added 6:00:00:00 code to
the folder and all the clips were given ascending not overlapping time code.
Now those .movs with time code act like the others and the AE can add a Tape
name in the 1080P 23.98 format. So what is QT change doing to make this
possible? From the error message when adding a tape name to the pre QT
change clip it would seem that Avid thinks of the project edit rate as 30
even though the project is set to 10809 23.98. I set QT change to the 23.98
setup so is Avid perhaps balking because it thinks the Canon clip is a true
24 and not 23.98? According to QT pro the original .movs from the camera
are 23.98. I realize QT Pro isn't always the most reliable at determining
fps but given it showed 23.98 and not 24 could that be causing Avids odd
behavior regarding adding a tape name.

I realize adding a tape name is problematic with ama sources but I can't
seem to break the AEs of this workflow. Perhaps these current issues may
sway them to use a comment column to track the ama sources and not the Tape
Name.

John Moore
Barking Trout Productions
Studio City, CA
bigfish@...

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