Bit rate / quallity of 1080p footage

[Gary Adcock]

[Ken Nemetchek] “I have concluded the following: because 1080p footage is spilt over two fields in the DVCPRO HD (60i) codec (@ 24 fps, I assume it is only 2 fields… or is it more?!)”

ken this has nothing to do with the DVCPROHD codec- 1080 24 is recorded as a Progressive Segmented Frame (psf) – or a progressive capture that plays back as interlace — this is even true for HDCAM. 1080 24 plays back as 48i.

The only true progressive capture in 1080 is to a tape deck or array from cameras like genesis & viper.

[Ken Nemetchek] ” I’m curious about just what the effective data rate would be in a FCP timeline.”

it is the same data rate

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL
gary@studio37.com

[Barry Green]

The 24p frames get imbedded in the 60i data stream the same way film gets transferred to video; by using 2:3 pulldown (or, in the 24pA mode, 2:3:3:2 pulldown). If the pulldown is removed, you’re left with an 80mbps data stream of 24p footage.

—————–
Get the most from your DVX camera. The DVX Book and DVX DVD are now available on ebay and at Amazon (https://www.fiftv.com/db)

[Ken Nemetchek]

Thanks for the information. I infer from your responces that the extra 20 mbs available in the codec would be used if recording @ 30 fps.

Thanks again.

Ken Nemetchek

Alberta Visual Communications

[Michael Brennan]

[gary adcock] “The only true progressive capture in 1080 is to a tape deck or array from cameras like genesis & viper.”

Surely all pro cameras with HDSDI output progressive, from camcorders Varicam to f900, studio cameras LDKs to HDCs.

Mike Brennan

[Gary Adcock]

[Michael Brennan] “Surely all pro cameras with HDSDI output progressive, from camcorders Varicam to f900, studio cameras LDKs to HDCs.”

Not really

the default format developed by Sony for 1080 capture is called a progressive segmented frame. It is a carry over of the interlaced SD format to that allows facilities and studios to still be able to use the new HD tools in their legacy workflow and transmission equipment. (or so that NEW J3 player can also play back a Beta tape in addition to HDCAM)

That is why the format is called 1080 24psf instead of the truly progressive version which is considered 1080p24.

Only the higher/ highest level of pro equipment can playback the segmented frames (48i) as a true 24p.

This is not to say that the PSF format is bad or somehow not possible to reconstituted back as progressive with the proper tools – it’s just that all but a few post houses or facilities have that need to justify the increased cost for them.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL
gary@studio37.com

[Michael Brennan]

What I was getting at was that f900 and other pro HD cameras output true progressive via HDSDI outputs on camera head to a hard drive, not only Viper and Genesis.

Mike Brennan