DNxHR SQ file size vs ProRes SQ file size. what's Wrong?

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Hakim Craddock

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DNxHR SQ file size vs ProRes SQ file size. what's Wrong?

PostMon Apr 15, 2019 5:12 pm

So i did 2 renders same 3 files using ffmpeg.
Prores SQ ffmpeg commend below:
-c:v prores_ks -profile:v 2 -qscale:v 7 -vendor ap10 -pix_fmt yuv422p10le -acodec pcm_s16le

DNxHR SQ comman below:
-c:v dnxhd -profile:v dnxhr_hq -pix_fmt yuv422p -acodec pcm_s16le

I end up with DNxHR SQ files that are roughly 6x the size of what i thought was a comparable ProRes counterpart codec. What am i doing wrong? My Machine plays the outputted Prores files with ease but it struggles to play the outputted DNxHR SQ files. both saved to .mov container.
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Andrew Kolakowski

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Re: DNxHR SQ file size vs ProRes SQ file size. what's Wrong?

PostMon Apr 15, 2019 8:29 pm

When you use profile then don't use qscale as they have impact on the same thing which is quantisation scale.
Use just profile:v and ProRes will be bigger as it should.

Also your DNxHR is for HQ quality not SQ. Change to -profile:v dnxhr_sq and tighter with fixed ProRes command you will get files with similar size. Just remember that DNxHR SQ is 8bit.
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Hakim Craddock

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Re: DNxHR SQ file size vs ProRes SQ file size. what's Wrong?

PostMon Apr 15, 2019 10:56 pm

Andrew Kolakowski wrote:When you use profile then don't use qscale as they have impact on the same thing which is quantisation scale.
Use just profile:v and ProRes will be bigger as it should.

Also your DNxHR is for HQ quality not SQ. Change to -profile:v dnxhr_sq and tighter with fixed ProRes command you will get files with similar size. Just remember that DNxHR SQ is 8bit.

So all this time i have been downgrading the quality on my prores encodes by using the qscale. Which is why my renders to prores is smaller. that makes since. To be honest i visually cant tell the difference. Do you think qscale will work on DNxHR SQ? im going to give it a try. if it yields me similar results as it does with Prores i will be happy.

Also i just realized that i had dnxhr_hq instead of sq :? ... But the files are still 4x bigger with DNxHR SQ. Thanks for the help, i think i understand where i went wrong now.
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Andrew Kolakowski

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Re: DNxHR SQ file size vs ProRes SQ file size. what's Wrong?

PostTue Apr 16, 2019 8:09 am

Qscale won't work for DNxHR if I'm correct- it only has strict SQ/HQ etc modes.
Smaller files for DNxHR can be done with dnxhr_lb preset, but of course quality goes down.
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Hakim Craddock

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Re: DNxHR SQ file size vs ProRes SQ file size. what's Wrong?

PostTue Apr 16, 2019 10:52 pm

Andrew Kolakowski wrote:Qscale won't work for DNxHR if I'm correct- it only has strict SQ/HQ etc modes.
Smaller files for DNxHR can be done with dnxhr_lb preset, but of course quality goes down.


Yes it your correct. I gave it a try and the file size was the same. I will have to give DNxHR lb a try and see if its good enough. Whats crazy is that my PC struggles with DNxHR SQ using a media player (pot player) But when i play it in resolve its VERY smooth and responsive. :? go figure.

Thank you very much for your help.
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Andrew Kolakowski

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Re: DNxHR SQ file size vs ProRes SQ file size. what's Wrong?

PostWed Apr 17, 2019 8:15 am

It's down to the code behind DNxHR decoder- they will for sure use different one. Use MPC-HC- it should play DNxHR fine.

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