1080i vs 1080p

[Greg Ondera]

So I am open. Tell me more, because I was going by Doug Jensen’s guidelines on using 60p. So it’s not so good for the web, eh?

Greg Ondera
http://www.Plexus.tv
http://www.SurgeonToday.org

[John Sharaf]

Greg,

Think about it; if every frame is different at 60p (mostly so with aggressive motion) then the compression engine has to recalculate every frame. If it’s 30p the math is half as hard, with much less chance of blocking up.

Furthermore when you shoot 60p and author to DVD you’ll be converting to 30p anyway as this is the native frame rate in order to fit twice as much material (and to write twice as fast). The hardware within the DVD playback converts it to 60i for display, or you can choose to stay progressive and it simply repeats each frame to maintain the proper timing.

JS

[Chris Babbitt]

If we apply this same logic to frame size, doesn’t the compressor workless hard when downrezing from 720 to 480 than it would when going from 1080 to 480?

[John Sharaf]

Actually not, there’s more “interrelation” required from 720 to 525/480 than from 1080.

JS

[John Sharaf]

Damn that spellchecker! Interpolation.

JS

[Ron Pestes]

Why does it matter how hard Compressor has to work? The final “look” is what we are after not giving Compressor a break. Personally I have had the best luck shooting in 60i for both the web and DVD. Shooting in 720 does not give me as sharp a look and 1080p can be too strobe like.

Apple Certified Master Pro FCS 2
Sony EX-3
MacBook Pro

[Chris Babbitt]

Ron,

Would you mind sharing your Compressor settings for encoding a 1080i file for DVD? I cannot get acceptable results. I get far better results with 720p.

[Craig Seeman]

Basically the problem people have with downconverting from 1080 especially from the high resolving of the EX cameras are issues around line twitter and related to fine detail. As a result 720p tends to be easier to get good results. It does depends on content though. Shoot talking heads and you may not see much difference. Shoot thin moving tree branches and you may get lots have line twitter going to 480.

[Ron Pestes]

OK, first I did not get good results with FCS2 but when I upgraded to FCS3 things changed. Not sure why. Anyway here are my settings.
For an HD file converted to SD for DVD I set the following:

In compressor under the “encoder” section “Quality” tab set Mode to “Two Pass VBR Best”,
Average bit rate to 6.7
Max bit rate to 7.9
Motion estimation to “best”

In the Frame Controls section set
Frame controls “on”
Resize filter “better”
Output fields “progressive”
Deinterlace “better”
Adaptive details check box is checked
Rate conversion “better”

This works great for footage shot with the Sony EX codec and also works well for HDV. But again for some reason this did not give me good results with Final Cut Studio 2, only FCS 3. Not sure why. Hope this helps.

Apple Certified Master Pro FCS 2
Sony EX-3
MacBook Pro

[Chris Babbitt]

So, you are de-interlacing? I’m on FCS2, by-the-way.