downsampling HDV to a good SD codec does work! at DVinfo.net

Michael Galvan · April 9th, 2006, 12:43 AM

So I've done my testing today on some HDV 24F to various SD codecs for higher chroma resolution in SD. My results ... downrezzing HDV 4:2:0 to a SD codec does retain the full color information the codec is capable of ...

I took the same clip and downconverted to DV, DVCPro50, and PhotoJPEG (at 100%). THen I brought it into Final Cut Pro (with each clip in their own respective timelines with the same properties as the clips themselves) and looked at the individual Cr and Cb channels of each clip in a side by side comparison. And sure enough, the PhotoJPEG had the same chroma res as its luma res. The DvcPro50 file was 4:2:2 and the DV 4:1:1. I did apply the same various filter sets to each of the clips and rendered ... the PhotoJPEG and DVCPro50 held up much cleaner than the DV clip.

And to finally confirm my tests, I took the DV compressed clip and bumped it up to DVCPro50 and dropped it side by side with my "native" DVCPro50 clip. After looking at the individual Cr and Cb channels again, the DV-to-DVCPro50 clip, showed the same chroma resolution of the DV clip, even though it was encoded up to DVCPro50, proving that your footage isn't any better than the highest compression scheme it has gone through.

This is great, as I never expected this kind of SD workflow from my H1. You really can get 4:2:2 or even 4:4:4 (or at least close to it) by downconverting HDV to the right SD codec. THis is great for any work I put out on DVD. Thanks for everyone's insight on this.

Kristian Indrehus · April 9th, 2006, 04:10 AM

And thanks to you for testing it. It really is good knews.

Steve Heise · May 26th, 2006, 05:27 PM

Can you direct me to how you did this??
I need to downrezz some of my HD video as well.

Ernesto Sanchez · May 27th, 2006, 11:17 AM

Thanks for posting this workflow.

April 9th, 2006, 12:43 AM	#1
Michael Galvan Major Player Join Date: Sep 2004 Location: New York, NY Posts: 775	downsampling HDV to a good SD codec does work! So I've done my testing today on some HDV 24F to various SD codecs for higher chroma resolution in SD. My results ... downrezzing HDV 4:2:0 to a SD codec does retain the full color information the codec is capable of ... I took the same clip and downconverted to DV, DVCPro50, and PhotoJPEG (at 100%). THen I brought it into Final Cut Pro (with each clip in their own respective timelines with the same properties as the clips themselves) and looked at the individual Cr and Cb channels of each clip in a side by side comparison. And sure enough, the PhotoJPEG had the same chroma res as its luma res. The DvcPro50 file was 4:2:2 and the DV 4:1:1. I did apply the same various filter sets to each of the clips and rendered ... the PhotoJPEG and DVCPro50 held up much cleaner than the DV clip. And to finally confirm my tests, I took the DV compressed clip and bumped it up to DVCPro50 and dropped it side by side with my "native" DVCPro50 clip. After looking at the individual Cr and Cb channels again, the DV-to-DVCPro50 clip, showed the same chroma resolution of the DV clip, even though it was encoded up to DVCPro50, proving that your footage isn't any better than the highest compression scheme it has gone through. This is great, as I never expected this kind of SD workflow from my H1. You really can get 4:2:2 or even 4:4:4 (or at least close to it) by downconverting HDV to the right SD codec. THis is great for any work I put out on DVD. Thanks for everyone's insight on this. __________________ www.michaelgalvan.com www.screenanthology.com

May 27th, 2006, 11:17 AM	#4
Ernesto Sanchez New Boot Join Date: Jan 2006 Location: Irvine CA Posts: 9	Great Info Thanks for posting this workflow.

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April 9th, 2006, 04:10 AM	#2
Kristian Indrehus Regular Crew Join Date: Sep 2005 Location: Norway Posts: 123	And thanks to you for testing it. It really is good knews.

May 26th, 2006, 05:27 PM	#3
Steve Heise Tourist Join Date: Mar 2006 Location: DC Area Posts: 1	Can you direct me to how you did this?? I need to downrezz some of my HD video as well.