View Full Version : Direct dvcprohd to DV from P2 card to dv tape transport?


Sergio Perez
July 31st, 2005, 08:36 PM
Is this feature possible? Kind of the same hdv to dv concept conversion, but from P2 to dv?

Chris Hurd
July 31st, 2005, 09:32 PM
Hi Sergio,

You're talking about an in-camera downconversion process from DVCPRO HD on the P2 card to DV25 on the tape, right? Just curious how you would use that feature.

Sergio Perez
August 1st, 2005, 01:17 AM
Hi Sergio,

You're talking about an in-camera downconversion process from DVCPRO HD on the P2 card to DV25 on the tape, right? Just curious how you would use that feature.

Yes, that's what I was thinking. The same way HDV is downconverted to DV trough a press of a button in the sony HDV cameras, probable we could get a similar feature that would downconvert the signal to DV Tape, letting us keep a dv master of the footage (for reference) as well as having the original HD footage in P2 file format.

Barry Green
August 1st, 2005, 01:27 AM
Yes you can do exactly that. The camera will do a realtime conversion from DVCPRO-HD on the P2 card, to DV on the tape.

Besides your stated interest (having a DV version), there's something else pretty cool you can do with it -- you can use the 720p variable-frame-rate footage and downconvert that, and it keeps the variable-frame-rate nature of the footage as you're downconverting. So basically, you can have variable frame rates in standard-def DV!

Sergio Perez
August 1st, 2005, 08:46 PM
Yes you can do exactly that. The camera will do a realtime conversion from DVCPRO-HD on the P2 card, to DV on the tape.

Besides your stated interest (having a DV version), there's something else pretty cool you can do with it -- you can use the 720p variable-frame-rate footage and downconvert that, and it keeps the variable-frame-rate nature of the footage as you're downconverting. So basically, you can have variable frame rates in standard-def DV!

Barry, that's what I wanted to hear! Now if the 9950 bundle came with two 16 gb cards... :)

Barry Green
August 2nd, 2005, 12:04 AM
16gb don't exist yet... so that's a bit much to be hoping for (but wouldn't that be nice!) The 16gb cards are likely to be announced at NAB 2006.

Jaser Stockert
August 2nd, 2005, 08:19 AM
barry i did a search, but no luck. can you give us a break down of record times on an 8gig p2 w/ every shooting mode(1080 60i/24p/30p, 720 24p/30p...480i...etc.) thanks and much appreciation!

Chris Hurd
August 2nd, 2005, 09:32 AM
Hi Jaser, see my chart, "P2 Card Capacities" located at:

http://www.p2info.net/articles/misc/p2cardcaps.php

I've got DV25, DV50, DV100 rates on there as well as 720p24 vs. 1080i60.

Hope this helps,

Thomas Smet
August 2nd, 2005, 04:01 PM
Chris wouldn't 720p 30p use the same data rate as DVCpro 50? Therefore 720p 24p should give you just a little bit more than DVCpro 50. If full HD or 720p 60p uses around 14 MB/s, then half of that or 720p 30p would use around 7 MB/s or the same data rate as the SD 50 format. 24p uses even less data than 30p so instead of 10 minutes on a 8GB card you should get around 20 minutes of 720p 24p. 10 minutes would be for 48p video.

Barry Green
August 2nd, 2005, 05:04 PM
Thomas is correct. 720/30p uses the same data rate as DVCPRO50, at 50 megabits. 720/24p uses 40 megabits. On an 8gb card you can get 20 minutes of 720/24p.

Chris Hurd
August 2nd, 2005, 05:06 PM
Yeah, and you know what else, I have notes in my hand now from Jan's seminar at DV Expo East last week... sure enough, 20 minutes on an 8GB card for 720p24. All I can say is...

D'oh!

...and give me a few minutes while I update that chart...

Chris Hurd
August 2nd, 2005, 05:15 PM
Okay fellows, can you check my math please... here is the updated chart:

P2 Card Capacities at http://www.p2info.net/articles/misc/p2cardcaps.php

(and folks remember the HVX200 allows for two P2 cards, so recording times to start off with on a pair of 8GB cards will be 1 hr. 4 min. for DV or DVCPRO, 40 min. for DVCPRO HD at 720p24, 32 min. for DVCPRO 50, and 16 min. for DVCPRO HD at 1080i60 or 720p60)

Barry Green
August 2nd, 2005, 06:04 PM
Looks right!

Jaser Stockert
August 2nd, 2005, 07:47 PM
thanks for the update! chris what's missing is 1080/30p and 1080/24p. which time category would these fall into? also, i assume all modes of dv 480/60i, 30p, 24p will be 32min(8gig p2)? thanks again!

Tom Wills
August 2nd, 2005, 08:21 PM
The two 1080p modes are both encased in a 1080i60 stream. Same times for it.

Barry Green
August 3rd, 2005, 03:01 AM
Tom is correct, all 1080 modes take up exactly the same amount of space and bandwidth.

Regarding DV/DVCPRO in 480/24p, 480/30p and 480/60i -- yes, your assumption is correct, all of those modes take up exactly the same amount of space, and would all get 32 minutes per 8gb card.