[Cin] UPD: Re: DNxHR presets

[Andrea paz]

The advantage of using mezzanine codecs (also called Intermediate
codecs) is that it preserves all the information in the original file
throughout the editing process. In addition, they are uncompressed
codecs and therefore not stressful for the CPU. They are indispensable
for high level works of Color Correction; denoise; mask and Chroma
Key, where the compression artifacts do not allow good results. For
only editing they are not necessary, and in fact proxies are often
used.