708 captions with 608 compatibility bytes

The tech spec's for delivery to Public Broadcasting System says to "Please ensure your 708 captions contain 608 compatibility bytes." Is this possible with Resolve 19.1.4?

AFAIK, you can only embed CEA 608 with Resolve. At least with Quicktime / ProRes.

Which codec do they ask?

Speaking about CEA 608, it generates a weird error in Mediainfo. I think it can be ignored because it doesn't appear in every version of Mediainfo:

General
Complete name : D:\Timeline 1.mov
Format : MPEG-4
Format profile : QuickTime
Codec ID : qt 0000.02 (qt )
File size : 506 MiB
Duration : 30 s 0 ms
Overall bit rate mode : Variable
Overall bit rate : 142 Mb/s
Frame rate : 25.000 FPS
Encoded date : 2025-05-02 15:44:37 UTC
Tagged date : 2025-05-02 15:44:37 UTC
Writing application : Blackmagic Design DaVinci Resolve Studio
Writing library : Apple QuickTime
Conformance errors : 1
moov : Yes
trak : Yes
mdia : Yes
minf : Yes
stbl : Yes
stsd : Yes
c608 : Yes
0x01FF0000 : Yes
General compliance : Element size 2847 is more than maximal permitted size 44 (offset 0x1FA507D1)

I can't find any revelant information about this.

EDIT: It really seems like a Mediainfo issue.

"PREFERED FORMATS:
DNx145, 220 or 220x files
XDCam 422 files with a MXF OP1a wrapper

"ADDITIONAL ACCEPTED FORMATS (but not preferred):
Apple ProRes 422
Apple ProRes 422 HQ"

You can't do it in Resolve (maybe in v20 beta, but I don't think so).
This has been discussed in other thread.
Resolve has quite substantial limitations when it comes to broadcast delivery (specially this "old fashioned" broadcast with XDCAM as master, etc.)

Your best bet is to push this request to Mainconcept, so they add it to their plugin.

I know some softwares that can do it but they cost a fortune...

Premiere does it, ( unless this "compatibility bytes" is something different than adding both tracks).
CineXtools also do it. Can be rented per day for 44$.
DrasticTV use to have simple inject tool as well but it's EOL.

Actually:
CEA-708: 708 was developed to replace 608 for HD television transmissions. 708 actually includes the 608 bytes as a compatibility layer for older decoding equipment, but also provides a completely new, enhanced captioning system. 708 is transmitted digitally as part of the compressed HD DTV stream. It is allocated ten times as much space, 9600 bits per second, as 608. Like 608, the meaning of the captions is described in the Consumer Electronics Association docs. The transmission of the packets is described in SMPTE 334-1 (VANC video packet) and as an ancillary packet in SMPTE 334-2.

So it's not 2 tracks but single 708 track, but with 'proper' format. Maybe Resolve does it.

I read the opposite about Premiere. At least for 708 / MOV container. But I might be wrong.

Drastic always writes 4:3 aspect ratio with english language. There's no way to customize.

I delivered files from Premiere to USA and this had both 708/608 and no complain. It was most likely MXF.
If anything doesn't work in Drastic then you contact them- it's not Adobe or BM where simplest fix takes a year They are way more responsive.