Scenarist SCC caption file timecode offset

[blyle504]

I have an MXF file on a Sony XDCam disc that has captioning embedded into the file.  I'm using AME to transcode the file and also create an scenarist scc file to send to a local TV station.

The file is being created without an issue, but the timecode on the scc file is off by about 45 seconds.  In watching the original file on a Sony XDCam disc, the first captioning on screen appears at approx timecode 09:46:54;00, but the scc file created through encoder has the first timecode as 09:47:28;25. Both source and scc file at drop frame.

Does anyone have an idea why the timecode is different?

Thanks,

Brad

[blyle504]

I ran the file through some old captioning software (CaptionMaker) from 2011 and can confirm that the time code issue is with Media Encoder.  Image below shows CaptionMaker's start time for CC text is 09:46:53;18.  I'd use this software, but the dongle doesn't work with Windows 8 or 10.

I exported an scc file and a subtitle file in AME and the same file open CaptionMaker.

[Stan Jones]

Is this correct?: You are importing a file that has an embedded closed caption stream. 608?

How are you placing it in a sequence?

What is the timecode in the sequence where the first caption starts?

Is your result the same if you "export" the file from PR rather than "queuing" to AME?

[blyle504]

The file has an embedded 608 closed caption stream.  It's a student newscast that records on campus and airs on a local TV station.  The station requires a sidecar file for captioning.  I'm not placing it in a sequence or using PR at all.  I'm using ME (CC2019) to export the original file (encoding from  MXF OP1a - XDCAM HD 35 60i to MXFOP1a - XDCAM HD 25 60i to lower the file size) and create the sidecar file. 

[Stan Jones]

Thanks. Do you have a short sample you can share?

[blyle504]

Sorry it took a couple of days...  here are links to two mxf test files

Link to original XDCam mxf file

Dropbox - Cap_test_orig.MXF

Link to AME MXF OP1a processed file

Dropbox - Cap_test_AME.mxf

Link to Scenarist scc file created with AME

Dropbox - Cap_test_AME.mxf.scc

The captions for the original file begin at 10:12:16;22

on the AME processed file, they start at 10:12:53;25

Thanks for your help,

Brad

[blyle504]

Here is the caption info I have comparing the two

[Stan Jones]

Got 'em. Unfortunately, I can't get to testing them today...

[blyle504]

Almost two years later to the date, but I wanted to provide an update... a resolution and warning for anyone else who may run into the same situation with the timing of a caption file off after running it through Media Encoder.

When I was using Media Encoder to process the files, I was setting in and out points in the render window to clip off the first part of the recording that the station didn't need.  So I would trim off anywhere from 30 to 45 seconds.  The time code for the SCC file appears to be married to the start of the clip that it is embedded and trimming the first part of the clip pushed all the captions back a corresponding amount.

In order to properly trim the file and keep the timing on the sidecar caption file, I had to use Premiere.

So bottom line for trimming any file with embedded caption, do not use Media Encoder but use Premiere to keep the timing accurate with captions.