Superwhites in AVCHD footage at DVinfo.net

Graham Hickling · September 7th, 2009, 11:53 PM

HDLink did a good job of retaining the superwhites in HDV footage from my Sony HC1. But it doesnt seem to retain them when it transcodes AVCHD footage from my Canon HF10.

Anyone else encounterered this?

(I've confirmed that there are indeed superwhites in the AVCHD footage ... they show up when, for example, I apply luminance reduction prior to transcoding with TMPGEnc).

Graham Hickling · September 8th, 2009, 07:31 PM

Hmmmm ... I'm clearly doing something wrong, as Stuart in the HF10 forum is able to retain his superwhites when he transcodes to Cineform: http://www.dvinfo.net/forum/canon-vi...ml#post1329381

Graham Hickling · September 9th, 2009, 09:23 AM

Well I (reluctantly) reloaded Premiere CS4 and have reassured myself that the superwhites are indeed still in the CFHD-avis that HDLink is producing (whew!). On a CS4 timeline the AVCHD and CFHD YC waveforms look almost identical.

But ...... when I load that same CFHD fie into a CS3 timeline, the superwhites vanish! And it's not just a scopes issue - if I pull the luminance down and re-render, the clipped area doesn't reappear.

Am I the only one seeing this in CS3??????

David Newman · September 9th, 2009, 11:28 AM

Data is never lost as all conversion happens in YUV space (values between 235-255 are super whites.) The truncation can happen if the calling application requests RGB 8-bit (which most do.) We support these supers in the 32-bit floats decodes for CS3 and CS4 (and CS2.) In Prospect HD/4K we provide the 32-bit float control in the Playback settings, if you using a Neo product, the 32-bit switch is somewhere in the project settings -- however it may not preview using 32-bit (that is an Adobe question.) If you are using CS3 Prospect is the way to go. If you are using Neo HD/4K with a tools that insist of 8-bit decodes, you can restore your supers using First Light. Open First Light and set the Gain 0.85 and for shadow supers, set the lift (or black offset) to around 0.05.

Graham Hickling · September 9th, 2009, 01:10 PM

Aha! Solved! I've recently been using ProspectHD with CS3 in 'Desktop' mode rather than 'Cineform HD' mode, and desktop mode lacks the 32-bit switch it seems.

Switching back to a Cineform HD project brings the superwhites back (However it also brings back red upside-down CHFD playback from the timeline, which some of us with Windows 7 are presently stuck with.)

September 7th, 2009, 11:53 PM	#1
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	Superwhites in AVCHD footage HDLink did a good job of retaining the superwhites in HDV footage from my Sony HC1. But it doesnt seem to retain them when it transcodes AVCHD footage from my Canon HF10. Anyone else encounterered this? (I've confirmed that there are indeed superwhites in the AVCHD footage ... they show up when, for example, I apply luminance reduction prior to transcoding with TMPGEnc).

September 9th, 2009, 11:28 AM	#4
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Data is never lost as all conversion happens in YUV space (values between 235-255 are super whites.) The truncation can happen if the calling application requests RGB 8-bit (which most do.) We support these supers in the 32-bit floats decodes for CS3 and CS4 (and CS2.) In Prospect HD/4K we provide the 32-bit float control in the Playback settings, if you using a Neo product, the 32-bit switch is somewhere in the project settings -- however it may not preview using 32-bit (that is an Adobe question.) If you are using CS3 Prospect is the way to go. If you are using Neo HD/4K with a tools that insist of 8-bit decodes, you can restore your supers using First Light. Open First Light and set the Gain 0.85 and for shadow supers, set the lift (or black offset) to around 0.05. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

September 8th, 2009, 07:31 PM	#2
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	Hmmmm ... I'm clearly doing something wrong, as Stuart in the HF10 forum is able to retain his superwhites when he transcodes to Cineform: http://www.dvinfo.net/forum/canon-vi...ml#post1329381

September 9th, 2009, 09:23 AM	#3
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	Well I (reluctantly) reloaded Premiere CS4 and have reassured myself that the superwhites are indeed still in the CFHD-avis that HDLink is producing (whew!). On a CS4 timeline the AVCHD and CFHD YC waveforms look almost identical. But ...... when I load that same CFHD fie into a CS3 timeline, the superwhites vanish! And it's not just a scopes issue - if I pull the luminance down and re-render, the clipped area doesn't reappear. Am I the only one seeing this in CS3??????

September 9th, 2009, 01:10 PM	#5
Graham Hickling Trustee Join Date: May 2004 Location: Knoxville, Tennessee Posts: 1,669	Aha! Solved! I've recently been using ProspectHD with CS3 in 'Desktop' mode rather than 'Cineform HD' mode, and desktop mode lacks the 32-bit switch it seems. Switching back to a Cineform HD project brings the superwhites back (However it also brings back red upside-down CHFD playback from the timeline, which some of us with Windows 7 are presently stuck with.)