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4K H264 --> DNXHD 10 bit: improved quality?

PostPosted: Sat Mar 18, 2017 10:41 am
by Janis Lionel
Hi there,

I know this is kind of and old discussion, but it still confuses me. I have the following scenario:

We recorded UHD with the Phantom 4 Pro in D-Log (H.264 codec). Once we were back, I transcoded the footage to DNXHD 10bit. When I put the original and the transcoded above each other and put the blend mode
to 'difference' there seems to be less compression loss in the DNXHD*.

So is it safe to say, that when you transcode from 4K H.264 to a HD 10bit that there is a quality increase of some sort?

Thanks for clarifying.

Cheers

*though I'm not quite sure; maybe there's more compression in the DNXHD file, but that wouldn't make sense.

Re: 4K H264 --> DNXHD 10 bit: improved quality?

PostPosted: Sat Mar 18, 2017 12:50 pm
by Andrew Kolakowski
No, pure transcoding to better quality format doesn't make quality better at all. It can only make it worse (until you use uncompressed format)!
How DNxHD is better- has it fixed possible h264 blocking, increased sharpness etc?

When you comparing against source your best results is no difference. Any difference means your transcoded file is worse than the source. Your source is reference.

In theory you can try to do some clever things during transcoding, try to increase depth, sharpen it etc, but this is processing not pure transcoding.