HV20 - Progressive mode recording

Ron Lemming · March 9th, 2007, 04:01 AM

That's the real beauty of working with 25p HDV as opposed to 24p HDV. All you have to do with 25p is take a matching HDV preset and set the fields to none or progressive.
I think 24p HDV needs some kind of additional support by the NLE?

Lee Wilson · March 10th, 2007, 06:03 AM

Quote:

Originally Posted by Ron Lemming

That's the real beauty of working with 25p HDV as opposed to 24p HDV. All you have to do with 25p is take a matching HDV preset and set the fields to none or progressive.
I think 24p HDV needs some kind of additional support by the NLE?

You in fact leave the project as HDV 50i interlaced as the 25 progressive frames are held in a 50i stream.

Ron Lemming · March 10th, 2007, 06:10 AM

So I should leave it at Lower Field First? But I thought there were no fields? I always set it to progressive and that worked for me. What would be better about leaving it at Lower Field First for instance?

Thomas Smet · March 10th, 2007, 07:56 AM

Quote:

Originally Posted by Lee Wilson

You in fact leave the project as HDV 50i interlaced as the 25 progressive frames are held in a 50i stream.

Lee see my post above as to why this can give bad results. A 50i timeline will mean everything added will render as 50i and not 25p. You have to use a 25p timeline in order for things to render correctly. Of course if you only ever do cuts only then you will not have much to worry about but even a cross dissolve will end up rendering as 50i. Now maybe mixing 50i effects and 25p raw video isn't that big if a deal to some people but if somebody shoots progressive they may want to keep everything progressive so it is good for them to know to choose a 25p project instead.

Pieter Jongerius · March 10th, 2007, 12:42 PM

...that's what I meant with semantics: it seems the same but it means something different. Another thing you want to avoid by not using a 50i timeline is a HDTV displaying the odd and even fields of the (once progressive)frame alternatively, deinterlacing them on the fly, thus decreasing vertical resolution and actually introducing flicker. Whoa...

So while in this case NLE input is (or seems) interlaced, output /must/ be progressive.

(That is, I have yet to produce my 1st progressive MPEG2 project, so for me this is theory until I receive my HV20...can't wait!)

Thomas Smet · March 10th, 2007, 09:13 PM

You will not be able to go back to tape as true progressive with the HV20. The 24p video would have to add the 3:2 back in and then encode to HDV.

Then again the HV20 does playback 24F so maybe a NLE could feed 24F if it was able to output 24F to the HV20. Even then the way 1080i works as soon as you hook up the HDMI cable the HDTV will treat it as 60i.

The only option I can see would be to create a true 24p HD-DVD or Blu-Ray disk. The HD disk players like progressive scan DVD players would be able to output true progressive frames via the HDMI or component output.

The other option of course is to create a 24p DVD by down converting your project to SD. If you can remove the pulldown in your NLE then 24p video from the HV20 should create some earth shattering 24p DVD's. I think the same should be true for 25p DVD's as well. I have never made a 25p DVD but I am pretty sure it works fine. Of course this no longer HD but it is one of the only ways to deliver progressive for interlaced worlds.

Ron Lemming · March 11th, 2007, 07:33 AM

Could I put 25p back on tape with the HV20 (since no pulldown needs to be reversed for 25p)?

Pieter Jongerius · March 11th, 2007, 02:02 PM

At this point I'm starting to wonder whether there are flags in something like a lead portion of the streams on tape / hard drive, that indicate the nature of the fields. There must be... Those are likely to be read and used by different elements of the production chain, including print-to-tape.

I did a brief scan in other area's here, but couldn't come up with something like that. Elsewhere I've found indication of such a flag being embedded in MPEG2 streams, that are used by DVD players and receivers to determine what to do with the fields and whether to deinterlace, inverse telicine or what.

It would be nice to be able to learn how to use those flags and not have to worry about these things...

Thomas Smet · March 11th, 2007, 03:48 PM

Since the HV20 plays back the F modes it is hard to say if F mode footage could be encoded from the 25p and then sent to the HV20. This may or may not work and we really will not know until the camera comes out.

As for normal HDV the video being sent back to the camera must be 50i. That means your 25p project will have to be encoded as a 50i HDV stream.

We also do not know if there will be any flags or not. Some HDV cameras have progressive flags while some do not.

We do have to remember that the HV20 is a consumer camera. Canon may have mostly put progressive recording in for mostly a look and not so much a format that is designed to have a end to end solution for progressive editing. That isn't to say that solutions will not come up in NLE's in the near future. In fact I'm sure Cineform will directly support removing the pulldown on the fly during capture. In this case if you shoot 25p or 24p with the HV20 you will end up with captured Cineform AVI files that really are progressive.

It would be nice if the HV20 adds flags to the video but at this point I doubt it. If it does then of course that makes an already sweet camera even better.

Mikko Lopponen · March 12th, 2007, 08:26 AM

Quote:

Originally Posted by Thomas Smet

With PAL 25p from the HV20 you do have to be carefull how it is dealt with in your NLE. To us the video looks progressive but to a NLE the video will look like interlaced video and it will process it in that way.
Any animated effects you may add in that timeline such as moving titles or any type of a wipe will end up rendering as 50i.

That can be changed with one click in the settings of any modern nle. The computers don't "see" anything.

Pieter Jongerius · March 12th, 2007, 01:03 PM

Hi Mikko,
true, but after configuring your project settings right, how do you know that the NLE won't deinterlace a 25p file assuming it's 50i? That's where flags might come in...

Again: can't wait. Is there anyone here who happens to have some 25p material we can experiment on?

March 9th, 2007, 04:01 AM	#16
Ron Lemming Regular Crew Join Date: Oct 2006 Location: Sweden Posts: 46	That's the real beauty of working with 25p HDV as opposed to 24p HDV. All you have to do with 25p is take a matching HDV preset and set the fields to none or progressive. I think 24p HDV needs some kind of additional support by the NLE?

March 10th, 2007, 06:10 AM	#18
Ron Lemming Regular Crew Join Date: Oct 2006 Location: Sweden Posts: 46	So I should leave it at Lower Field First? But I thought there were no fields? I always set it to progressive and that worked for me. What would be better about leaving it at Lower Field First for instance?

March 10th, 2007, 12:42 PM	#20
Pieter Jongerius Regular Crew Join Date: Jan 2007 Location: Netherlands Posts: 101	...that's what I meant with semantics: it seems the same but it means something different. Another thing you want to avoid by not using a 50i timeline is a HDTV displaying the odd and even fields of the (once progressive)frame alternatively, deinterlacing them on the fly, thus decreasing vertical resolution and actually introducing flicker. Whoa... So while in this case NLE input is (or seems) interlaced, output /must/ be progressive. (That is, I have yet to produce my 1st progressive MPEG2 project, so for me this is theory until I receive my HV20...can't wait!)

March 10th, 2007, 09:13 PM	#21
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	You will not be able to go back to tape as true progressive with the HV20. The 24p video would have to add the 3:2 back in and then encode to HDV. Then again the HV20 does playback 24F so maybe a NLE could feed 24F if it was able to output 24F to the HV20. Even then the way 1080i works as soon as you hook up the HDMI cable the HDTV will treat it as 60i. The only option I can see would be to create a true 24p HD-DVD or Blu-Ray disk. The HD disk players like progressive scan DVD players would be able to output true progressive frames via the HDMI or component output. The other option of course is to create a 24p DVD by down converting your project to SD. If you can remove the pulldown in your NLE then 24p video from the HV20 should create some earth shattering 24p DVD's. I think the same should be true for 25p DVD's as well. I have never made a 25p DVD but I am pretty sure it works fine. Of course this no longer HD but it is one of the only ways to deliver progressive for interlaced worlds.

March 11th, 2007, 07:33 AM	#22
Ron Lemming Regular Crew Join Date: Oct 2006 Location: Sweden Posts: 46	Could I put 25p back on tape with the HV20 (since no pulldown needs to be reversed for 25p)?

March 11th, 2007, 02:02 PM	#23
Pieter Jongerius Regular Crew Join Date: Jan 2007 Location: Netherlands Posts: 101	At this point I'm starting to wonder whether there are flags in something like a lead portion of the streams on tape / hard drive, that indicate the nature of the fields. There must be... Those are likely to be read and used by different elements of the production chain, including print-to-tape. I did a brief scan in other area's here, but couldn't come up with something like that. Elsewhere I've found indication of such a flag being embedded in MPEG2 streams, that are used by DVD players and receivers to determine what to do with the fields and whether to deinterlace, inverse telicine or what. It would be nice to be able to learn how to use those flags and not have to worry about these things...

March 11th, 2007, 03:48 PM	#24
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	Since the HV20 plays back the F modes it is hard to say if F mode footage could be encoded from the 25p and then sent to the HV20. This may or may not work and we really will not know until the camera comes out. As for normal HDV the video being sent back to the camera must be 50i. That means your 25p project will have to be encoded as a 50i HDV stream. We also do not know if there will be any flags or not. Some HDV cameras have progressive flags while some do not. We do have to remember that the HV20 is a consumer camera. Canon may have mostly put progressive recording in for mostly a look and not so much a format that is designed to have a end to end solution for progressive editing. That isn't to say that solutions will not come up in NLE's in the near future. In fact I'm sure Cineform will directly support removing the pulldown on the fly during capture. In this case if you shoot 25p or 24p with the HV20 you will end up with captured Cineform AVI files that really are progressive. It would be nice if the HV20 adds flags to the video but at this point I doubt it. If it does then of course that makes an already sweet camera even better.

March 12th, 2007, 01:03 PM	#26
Pieter Jongerius Regular Crew Join Date: Jan 2007 Location: Netherlands Posts: 101	Hi Mikko, true, but after configuring your project settings right, how do you know that the NLE won't deinterlace a 25p file assuming it's 50i? That's where flags might come in... Again: can't wait. Is there anyone here who happens to have some 25p material we can experiment on?