Create a master with sub black et super white data

Hi,
I would like to export a master keeping the data video below data levels 1023. I am working with REC709 footages, my project is set to Davinci YRGB Color managed.
When I export, I chose Retain sub black and super white data, but it does not work. The format used is Avi Grassvally HQX, it tried other format, same problem. Maybe I have to change my color workspace, the best would be that it does not change the color of my REC709 footage.
The purpose is to be able to edit the color later without loosing data.
Thanks!

Try 16-bit float, ProRes 4444, ProRes 4444 XQ or DNxHR 444 and see if the data is retained. This is an issue with optimized media and caches (some codecs won't retain sub and super data).

Thanks for you answer, I tried DNxHR 444, but the same problem appear, all the data below 1023 is lost.

all the data below 1023 is lost.

Say what, now?

Sorry my english is not very good. I wanted to say over 1023. Maybe there is a normalize parameter somewhere I missed.

For data levels, there is no such thing as sub-black and super-white. Use video levels to retain those values.

Video levels will not preserve the sub and super data, if the codec doesn't. The manual makes this point several times, with respect to optimized media and caches. The same appears to be true of exports. Try it.

Video levels will not preserve the sub and super data, if the codec doesn't. The manual makes this point several times, with respect to optimized media and caches. The same appears to be true of exports. Try it.

Obviously, you need a codec that does.
ProRes does and so does H.264 and H.265.

Obviously, you haven't read the manual, if you think h.264/5 or Prores 422 does. Or if you don't believe the manual, try it for yourself.

Obviously, you haven't read the manual, if you think h.264/5 or Prores 422 does. Or if you don't believe the manual, try it for yourself.

I did; as long as you check the maintain super whites, it is fine.

The manual offers repeated warnings for not using your preferred codecs for generating optimized media and caching if data is to be preserved, and that was also my experience with exports, though before v19: the exports were not identical to the original. Super whites/sub blacks either weren't there or were significantly altered.

If they've managed to avoid or correct the issue on exports the OP apparently isn't seeing it, though to be fair, I'm not sure the matter was entirely resolved with their recommended formats either.

The manual offers repeated warnings for not using your preferred codecs for generating optimized media and caching if data is to be preserved, and that was also my experience with exports, though not with v19: the clips were not identical to the originals with respect to super whites/sub blacks.

If they've managed to avoid or correct the issue on exports the OP apparently isn't seeing it, though to be fair, I'm not sure the matter was entirely resolved with their recommended formats either.

I never use optimized media. When you deliver video levels and use ProRes or H.264/H.265 and maintain super whites, there is no problem.

For 4:4:4 exports I would use exclusively data levels.