Downcoverting Dvcpro Hd at DVinfo.net

Edwin Hernandez · July 15th, 2005, 08:30 PM

A COUPLE OF QUESTIONS:

#1- OK, let's assume I shot something with the P2 cards,
then take it to my FCP5 for editing with the DVCPRO HD codec.
But then, I want a version in SD using the DV/DVCPRO NTSC codec or the DVCPRO50 codec . Can I downcovert it with Quicktime,
or should it be done through a specialized hardware?

#2- I don't "really" have any HD requirements, but maybe I can use the DVCPRO 50 mode, is it appropiate to buy the camera without the P2 cards and then wait until something happens with the price of it? Will the difference in quality between the DV tape and the DVCPRO 50 footage will be noticeable in the same camera?

#3- Do you think there will be P2 card rentals? or is it too risky for anyone to attempt it?

-EDWIN

Thomas Smet · July 15th, 2005, 09:20 PM

You should shoot DVCpro 50 if all you want is SD.

The nice thing about DVCpro 50 is that it uses the full 720x486 resolution and has very little compression around 3.3:1 along with nice 4:2:2 color.

Thats about as good as you can get in the SD world without going live uncompressed.

DVCproHd has much higher levels of compression and will give you uneven results when you scale down because of the anamorphic pixels. Besides converting means lots of rendering time compared to the DVCpro50 footage that is ready to edit right away.

Scott Anderson · July 16th, 2005, 09:47 AM

#1: I'm sure that you can do the downconversion from DVCProHD to SD in Quicktime. Thomas - why would you think that this conversion would cause problems? Have you actually done downconversions from DVCProHD to DV50 or DV25? It seems to me that with such a huge amount of picture information in DVCProHD, the down-conversion would be extremely clean. In fact, I have seen Varicam footage downconverted in FCP that looked awesome, and that's the same codec. Granted, the 1/3" chips and different optics will make a difference, but Panasonic is already talking about this camera as a viable B-Camera on Varicam shoots. I don't think they'd be doing that if they weren't confident in the image quality. Also, since current G5's can work with DVCProHD real-time, I don't think the render times will be excessive. My workflow would be to stay DVCProHD all the way until final mastering, then make multiple masters for HD, DV50 and MPEG-2 for DVD.

#2: I think it's perfectly appropriate to use this camera without P2 cards, shooting only DV. This may turn out to be the last, best DV25 format small camera ever made. That being said, DV50 is far superior. The difference may be hard to spot for many people, but when you get into a situation of heavy post-processing, like chroma keying or heavy color correction, DV50 will make the footage much easier to work with. Keep in mind, of course, that you can only shoot DVCPro50 onto P2 cards or a Firestore.

#3: For those projects that will need HD, or even those projects you think MAY need HD in the future, rental options will almost certainly be available. I have said this many times before. Rental houses that purchase multiple HVX's will almost certainly buy multiple P2 cards, as renters will demand to be able to shoot all day without downloading from the cards. This will, most likely, create a robust rental market for all those extra P2 cards. The rental prices may be steep due to the purchase price of the cards, but for an occasional HD shooter, it's still much less expensive than renting a Varicam. Rental houses will also buy whatever Firestore-like solution becomes available, so renting that unit may turn out to be the bast option of all, both for private owners AND rental houses.

Thomas Smet · July 16th, 2005, 10:40 PM

Don't get me wrong, I think down converting can give good results. The problem is that HD is compressed a lot more. Even when you scale down some of those artifacts may still show up. I can't really say for sure though until I get some footage from the HVX200 and compare the results. Down scaling will always loose a little bit of detail. If you have thin objects such as hair in HD and down convert you could get either softer edges or missed details. For example lets say you have a red pixel on it's own. When you scale down that red pixel gets interpolated to hwere it may even not show up but get cut out. Depending on what you are shooting this may actually be better. I don't think either will look bad just different.

Even if rendering is fast it could mean extra steps depending on what you are doing with the footage.

Peter Jefferson · July 17th, 2005, 01:12 AM

the DVCProHD codec is a lil more robust that that of HDV, being that the compression is within the individual frame level, not the GOP

downconversion will be sweeeeeeeeeeeeet

Brandon Tubek · July 22nd, 2005, 08:30 AM

I will try to give some answers to your questions with the best of my knowledge on FCP5 (although I am primarily a Vegas 6 user).

#1: You should be able to down convert from DVCPRO HD to DVCPRO 50 due to the built in codecs in FCP5. As FCP5 and its quick time codecs were designed originally as a native DVCPRO HD and 50 system, it should have no problem doing so without external acceleration hardware. Try it out... if not you may want to look into a down conversion program or plug in.

#2: I think that is a smart move on your part. First buy the camera than wait for p2 capacity to increase and become less expensive. I however am going to wait for the release of the second generation of this camera, I will put my money up for p2 cards after they have been extensively field tested.

#3: I do not think renting would be a problem. Maybe even by mail order from someone like B&H or EVS online. I'm sure they would have you sign an electronic contract form saying that you are responsible for all damages any loss of the p2 cards. This may become a market, but its up to the big wigs. Panasonic may put a rental restriction upon p2 cards as well, since they are re-write media. Think of this as how you cannot rent a mini DV tape, or PC/MAC software for that matter.

hope that helps, even though that's only summing up my personal thoughts :)

Chris Hurd · July 22nd, 2005, 09:16 AM

I seriously doubt that Panasonic would put any sort of restriction on P2 card rentals. I think it's a given that if a rental house chooses to offer the HVX, then they would also have at least a couple, probably several P2 cards to go with it.

Quote:

maybe I can use the DVCPRO 50 mode, is it appropiate to buy the camera without the P2 cards...?

If you buy the camera without the cards, then you are limited to the DV25 formats of DV and DVCPRO. In order to record DVCPRO 50, you must have the P2 cards.

Barry Green · July 22nd, 2005, 03:20 PM

Quote:

Originally Posted by Chris Hurd

If you buy the camera without the cards, then you are limited to the DV25 formats of DV and DVCPRO. In order to record DVCPRO 50, you must have the P2 cards.

Or a FireStore or HD Rack or a direct firewire connection to a PC or Mac running Avid Express HD or FCP-5 or any other NLE that supports DVCPRO-HD.

Chris's statement should be clarified: only miniDV can be recorded on the internal tape drive. To record DVCPRO50, you'll need a P2 card *or* one of the many ways to capture the firewire output of the camera.

Chris Hurd · July 22nd, 2005, 04:06 PM

Ah-hah. Thanks for the clarification, Barry-Wan. Much appreciated,

Bon Sawyer · July 25th, 2005, 07:35 PM

Quote:

Originally Posted by Chris Hurd

If you buy the camera without the cards, then you are limited to the DV25 formats of DV and DVCPRO.

I didn't think it would be able to shoot DVCPRO (25) onto tape either?

-Bon

Barry Green · July 25th, 2005, 07:36 PM

Correct. Only miniDV to the internal tape drive.

Paul Matwiy · July 28th, 2005, 12:39 PM

My opinion is that the added compression in HD mode is more than offset by the improved color sampling of 4:2:2 when in DVCPRO-HD. I don't know for sure if the camera actually downconverts from a higher res when shooting NTSC or not. It may just remap the pixels in the CCD array. Shooting high and then downconverting in software will have the advantage or reducing aliasing artifacts since a more sophisticated low pass filter can be used in the down conversion. This is one of the reasons Hollywood moved to HD transfers of film for DVD mastering.
Paul

Anhar Miah · July 29th, 2005, 08:43 AM

@ Paul,

Do you have anymore infomation on this low pass filters that are used by Hollywood production for downconversation? any links or further explantion would be very helpfull indeed.

Anhar Hussain Miah

Paul Matwiy · July 29th, 2005, 11:17 AM

Quote:

Originally Posted by Anhar Miah

@ Paul,

Do you have anymore information on this low pass filters that are used by Hollywood production for down-conversation? any links or further explanation would be very helpful indeed.

Anhar Hussain Miah

Down-conversion usually applies a Discrete Cosine Transform (DCT) to the data. The type and length of the filters is usually proprietary to the application or equipment used, and much depends on whether or not the original signal is interlaced, progressive, and the actual frame rate. There is a cursory article on the challenges here : http://bg.broadcastengineering.com/a...at_converters/

Here is one excerpt from the article: "Filtering in the down-converter can be more closely controlled than filtering in an SD-originating chain (the camera lens, CCD processing, etc). This means that it is possible to produce sharper images by using down-conversion than by using SD-originated material while suppressing alias signals." As I said, the quality of the result will be dependant on the software you use to down-convert and transcode. Obvious vendors are Pinnacle/Avid, Adobe Premiere Pro, and Apple Finalcut.

Interestingly, a form of analogue filtering was used on the "olden days" of telecine. Using flying spot scanners, the beam spot size and scanning speed would be enlarged or reduced depending on the NTSC aliasing artifacts visible. Typically, spot size affected interline "twitter" and scanning speed affected horizontal resolution.

Edwin Hernandez · July 29th, 2005, 11:26 PM

I have a DVCPRO HD DVD called ACCESS HD by Panasonic. It is a demo for the Varicam.

I took the video and downconverted it with Final Cut and with Quicktime. Man, it does look great. Just like film. The image was 720p @24p. I know Varicam is a 2/3" CCD camera, but hey, the HVX200 is a 1080p @24p camera, despite its 1/3" CCD. So it must look great too!

/EDWIN

July 22nd, 2005, 08:30 AM	#6
Brandon Tubek New Boot Join Date: Jul 2005 Location: Farmington Hills, Michigan, USA Posts: 10	To Edwin I will try to give some answers to your questions with the best of my knowledge on FCP5 (although I am primarily a Vegas 6 user). #1: You should be able to down convert from DVCPRO HD to DVCPRO 50 due to the built in codecs in FCP5. As FCP5 and its quick time codecs were designed originally as a native DVCPRO HD and 50 system, it should have no problem doing so without external acceleration hardware. Try it out... if not you may want to look into a down conversion program or plug in. #2: I think that is a smart move on your part. First buy the camera than wait for p2 capacity to increase and become less expensive. I however am going to wait for the release of the second generation of this camera, I will put my money up for p2 cards after they have been extensively field tested. #3: I do not think renting would be a problem. Maybe even by mail order from someone like B&H or EVS online. I'm sure they would have you sign an electronic contract form saying that you are responsible for all damages any loss of the p2 cards. This may become a market, but its up to the big wigs. Panasonic may put a rental restriction upon p2 cards as well, since they are re-write media. Think of this as how you cannot rent a mini DV tape, or PC/MAC software for that matter. hope that helps, even though that's only summing up my personal thoughts :)

July 22nd, 2005, 04:06 PM	#9
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	Ah-hah. Thanks for the clarification, Barry-Wan. Much appreciated, __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 28th, 2005, 12:39 PM	#12
Paul Matwiy Regular Crew Join Date: Jul 2004 Location: Marin, CA Posts: 85	Downconversion My opinion is that the added compression in HD mode is more than offset by the improved color sampling of 4:2:2 when in DVCPRO-HD. I don't know for sure if the camera actually downconverts from a higher res when shooting NTSC or not. It may just remap the pixels in the CCD array. Shooting high and then downconverting in software will have the advantage or reducing aliasing artifacts since a more sophisticated low pass filter can be used in the down conversion. This is one of the reasons Hollywood moved to HD transfers of film for DVD mastering. Paul __________________ Paul

July 15th, 2005, 08:30 PM	#1
Edwin Hernandez Regular Crew Join Date: Sep 2004 Location: Panama City, Panama Posts: 162	Downcoverting Dvcpro Hd A COUPLE OF QUESTIONS: #1- OK, let's assume I shot something with the P2 cards, then take it to my FCP5 for editing with the DVCPRO HD codec. But then, I want a version in SD using the DV/DVCPRO NTSC codec or the DVCPRO50 codec . Can I downcovert it with Quicktime, or should it be done through a specialized hardware? #2- I don't "really" have any HD requirements, but maybe I can use the DVCPRO 50 mode, is it appropiate to buy the camera without the P2 cards and then wait until something happens with the price of it? Will the difference in quality between the DV tape and the DVCPRO 50 footage will be noticeable in the same camera? #3- Do you think there will be P2 card rentals? or is it too risky for anyone to attempt it? -EDWIN

July 15th, 2005, 09:20 PM	#2
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	You should shoot DVCpro 50 if all you want is SD. The nice thing about DVCpro 50 is that it uses the full 720x486 resolution and has very little compression around 3.3:1 along with nice 4:2:2 color. Thats about as good as you can get in the SD world without going live uncompressed. DVCproHd has much higher levels of compression and will give you uneven results when you scale down because of the anamorphic pixels. Besides converting means lots of rendering time compared to the DVCpro50 footage that is ready to edit right away.

July 16th, 2005, 09:47 AM	#3
Scott Anderson Major Player Join Date: May 2003 Location: Phoenix, AZ Posts: 327	#1: I'm sure that you can do the downconversion from DVCProHD to SD in Quicktime. Thomas - why would you think that this conversion would cause problems? Have you actually done downconversions from DVCProHD to DV50 or DV25? It seems to me that with such a huge amount of picture information in DVCProHD, the down-conversion would be extremely clean. In fact, I have seen Varicam footage downconverted in FCP that looked awesome, and that's the same codec. Granted, the 1/3" chips and different optics will make a difference, but Panasonic is already talking about this camera as a viable B-Camera on Varicam shoots. I don't think they'd be doing that if they weren't confident in the image quality. Also, since current G5's can work with DVCProHD real-time, I don't think the render times will be excessive. My workflow would be to stay DVCProHD all the way until final mastering, then make multiple masters for HD, DV50 and MPEG-2 for DVD. #2: I think it's perfectly appropriate to use this camera without P2 cards, shooting only DV. This may turn out to be the last, best DV25 format small camera ever made. That being said, DV50 is far superior. The difference may be hard to spot for many people, but when you get into a situation of heavy post-processing, like chroma keying or heavy color correction, DV50 will make the footage much easier to work with. Keep in mind, of course, that you can only shoot DVCPro50 onto P2 cards or a Firestore. #3: For those projects that will need HD, or even those projects you think MAY need HD in the future, rental options will almost certainly be available. I have said this many times before. Rental houses that purchase multiple HVX's will almost certainly buy multiple P2 cards, as renters will demand to be able to shoot all day without downloading from the cards. This will, most likely, create a robust rental market for all those extra P2 cards. The rental prices may be steep due to the purchase price of the cards, but for an occasional HD shooter, it's still much less expensive than renting a Varicam. Rental houses will also buy whatever Firestore-like solution becomes available, so renting that unit may turn out to be the bast option of all, both for private owners AND rental houses. Last edited by Scott Anderson; July 16th, 2005 at 10:03 AM.

July 16th, 2005, 10:40 PM	#4
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	Don't get me wrong, I think down converting can give good results. The problem is that HD is compressed a lot more. Even when you scale down some of those artifacts may still show up. I can't really say for sure though until I get some footage from the HVX200 and compare the results. Down scaling will always loose a little bit of detail. If you have thin objects such as hair in HD and down convert you could get either softer edges or missed details. For example lets say you have a red pixel on it's own. When you scale down that red pixel gets interpolated to hwere it may even not show up but get cut out. Depending on what you are shooting this may actually be better. I don't think either will look bad just different. Even if rendering is fast it could mean extra steps depending on what you are doing with the footage.

July 17th, 2005, 01:12 AM	#5
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	the DVCProHD codec is a lil more robust that that of HDV, being that the compression is within the individual frame level, not the GOP downconversion will be sweeeeeeeeeeeeet

July 25th, 2005, 07:36 PM	#11
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Correct. Only miniDV to the internal tape drive.

July 29th, 2005, 08:43 AM	#13
Anhar Miah Major Player Join Date: Dec 2003 Location: United Kindom, England Posts: 290	@ Paul, Do you have anymore infomation on this low pass filters that are used by Hollywood production for downconversation? any links or further explantion would be very helpfull indeed. Anhar Hussain Miah

July 29th, 2005, 11:26 PM	#15
Edwin Hernandez Regular Crew Join Date: Sep 2004 Location: Panama City, Panama Posts: 162	I have a DVCPRO HD DVD called ACCESS HD by Panasonic. It is a demo for the Varicam. I took the video and downconverted it with Final Cut and with Quicktime. Man, it does look great. Just like film. The image was 720p @24p. I know Varicam is a 2/3" CCD camera, but hey, the HVX200 is a 1080p @24p camera, despite its 1/3" CCD. So it must look great too! /EDWIN