I need some confirmation regarding the work-flow of a project I am about to output for local broadcast please ...

Deliveralbe is 1080i/59.94

- Source Footage / Avid Project Rate: 1080p/23.976

- I am using Avid's 30DF timeline timecode to bring the show to required time (22 mins.)

- Planning to use Avid's Crossconvert to achieve output to 1080i/59.94

- Closed Captioning is handled by an outside source.  I am thinking that the TC burn DVD for transcription should have the 30DF display for timing and that should then correctly sync to the 1080i/59.94 master on the layback.

Thoughts are appreciated.

Thank you!

I think you're correct in your assumptions. I don't know how Avid Crossconvert works because I typically use external standards converters but 30DF TC should match your 59.94i output timecode.

The important thing to remember is that your overall timing does not change regardless of the frame rate. If the show is 1 hour long it will stay that length 99% of the time (there are rare occurences when you actually change the speed like Slow PAL or applying and removing pulldown).

Captioning has a pretty wide margin of error. Even if you delivered a DVD with 24 base TC to the captioning house the file they create would still be within tolerance for encoding. For example, if a line of text comes in at:

01:10:25:15 in 24 base TC

01:10:25:19 is the 30 base TC equivalent

So it's a mere 4 frames offset in this case and 6 frames maximum offset which in my opinion is acceptable for closed captioning.

The workflow is fine.

Michael

Sweet. Thank you both!