DNxHD 444 versus DNxHD HQX

Report · Aug 07, 2017

Hi all,

I wonder if someone can help me? I recently upgraded my edit boxes and did a full reinstall of Win64 & Adobe CC Premiere Pro. Since doing that, I also decided to switch from using DNxHD HQX to DNxHD 444. I've come across something I don't understand and I can't find an explanation.

I shoot on Sony HDV cameras (Z5E & Z7E). In the past, I would use Adobe Media Encoder to transcode all my MTS files into DNxHD and then edit them. When I did this, I used the colour workspace in Premiere to pull down the highlights and there was always some information above the 100 line, so my shots would quite often go from a white / blown out looking sky to a natural blue sky.

When I transcode to DNxHD, this doesn't happen. Same thing again; I go to the colour workspace and I pull down the highlights. There is no information above the 100 line on the scope and therefore, I'm not bringing that missing information back into the image. The sky effectively stays white or blown out looking.

Why is this?

I would have thought that there would be even more information in the DNxHD 444 data than the HQX data. But it seems that AME simply throws away data during the transcode. I am at this very moment, transcoding my HDV files to DNxHD HQX so that I can continue my edit. Time is money and all that. But it sure would be interesting to figure out what's going on.

Any takers? Thanks in advance. 🙂

Kind regards, Andrew.

Report · Dec 04, 2017

There is a peculiar case about these 2 codecs, that I happened to test within Davinci Resolve.

It seems, that the "DNxHD 444" may be only 10-bit, versus the "DNxHD HQX" which is 12-bit.

These 2 bits of data are in fact, a lot of data. Maybe that is where you are loosing your detail.

Here is the original topic:

Blackmagic Forum • View topic - DNxHR 444 12-bit is only 10-bit

Report · Dec 04, 2017

I would be surprised if Emilian's explanation is correct.

My thinking is that one preset is treating the footage as Full level (0-255), and the other is treating it as Video level (16-235).