Film-Tech Forum ARCHIVE: Sync audio problems when splicing trailers

This is topic Sync audio problems when splicing trailers in forum Large Format Forum at Film-Tech Forum ARCHIVE.

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Posted by Ivan Plamondon (Member # 7637) on 06-16-2013, 12:34 PM:

I seem to have failed at my first attempt to splice a trailer onto our current feature film. Followed the "splice here" directive of the trailer and attached it to the frame just before the single number 2 (47 frames before the start of the feature). The audio however is out of sync, coming in about two seconds too late! Do I need to use the "offset" procedure of our DDP-2 program to correct?

Posted by Tony Bandiera Jr (Member # 2365) on 06-17-2013, 12:28 PM:

If I understand how large format audio is sync'd up, wouldn't the trailer itself be the cause? Is there any kind of timecode on the film itself? (If the trailer plays out of sync but the feature plays with proper sync I would suspect this to be the case.)

If not, then the problem is the "cut here" mark was placed improperly. It has happened before even in standard 35mm (I had a premier of "Happy, Texas" get cancelled because the editors added a Miramax logo to reel one..and forgot to add blank mag track to the sound roll. Sync there was off a full 15 seconds.)

Posted by Cameron Glendinning (Member # 3516) on 06-18-2013, 07:23 PM:

No Timecode on the film Tony. Could it be the number of frames programmed into the projector presets? Maybe you should subtract 48? That way the DDP will start 2 seconds earlier.

I am no expert and would be able to ask one in a couple of weeks if you like.

Posted by Cameron Glendinning (Member # 3516) on 06-18-2013, 11:08 PM:

Just realized that the above post made some assumptions that have no basis. Is it just the trailer that's out of sync? Are you also running the feature on mag? or do you switch over to a digital audio source.

Posted by Adam Martin (Member # 641) on 06-18-2013, 11:38 PM:

"Splice Here" refers to the separation of the leader from the first frame of picture and should be 48 frames after the "2" frame. If you have attached the FFP to the 2-frame of the leader, then you have essentially removed 2 seconds of leader and the douser will open 2 seconds into the picture and the audio will be 2 seconds behind.

Also note that you will need to tell the DDP-2 where the audio transition between the trailer and feature should occur once you have the trailer audio in sync. This should be covered in the DDP manual, unless that manual is as useless as the DTAC manual was.

Posted by Ivan Plamondon (Member # 7637) on 06-22-2013, 07:35 AM:

My iniitial training had me splice the tail section of the trailer at the "Splice Here" area (duh!) and attach it to the 47th frame of black (just before the last number 2)of our Feature movie. The idac (DDP-2 software)has the ability to manipulate the smpte timing by adding an offset (in this case, at the end of the Trailer) to make up for the extra frames. My plan at this moment will be to stop the projector at the end of the trailer, and manually move the rotor until the spliced section is where "picture start" would normally be. Once there, I can note the projector time and make the required adjustment. FYI, no time code strip on the film. All audio sync'd via digital audio on the DDP-2.

Posted by Ivan Plamondon (Member # 7637) on 06-30-2013, 04:35 PM:

Here is how the math ends up working out for adding trailers to our Niagara Feature:

Iron Man 3 Trailer has 3758 frames from the first frame to the last frame of black (does NOT include the 192 frames of numbers after "picture Start".

3758 frames plus 47 frames of black (before the first frame of the Niagara Feature)

3758 + 47 = 3805 frames divided by 24 frames per second = 158.54 seconds

158.54 seconds divided by 60 = 2.642 minutes = 2 mins and 38.52 seconds

2 mins and 38.52 seconds = 00:02:38.13

And this becomes the Total Region Length of the IRON Man 3 Trailer

Registered Length = 00:02:40.00
Offset = 00:00:01.11
Total Region Length = 00:02:38.13