Jan

I don't know if this in your scope of "able to talk about", but I saw this question raised on another forum, and I thought it was worth a shot.

Will the "little camera" (that now has a name) have essentially variable compression ratios for different frame rates, for instance: 720 60p would have a higher compression than 720 24p keeping the stream at 100 mbps? Or will their be the same compression across the range of resolution/frame rates, with the 720 24p essentially haveing a "true" bandwidth of something like 40mbps?

Barry

(by the way thank you for you gracious and informative comments on these boards..you put up with a lot of hooey sometimes)

Hi Barry,

DVCPRO has the same amount of compression per frame. Each frame stands on it own. The resolution is the same on a frame per frame basis. Unlike MPEG2.

Doe sthat answer the question?

Best,

jan

Jan

I'm not sure. Let me phrase it the way it was put over at dvxuser...When shooting in 720 24p...are we really shooting 60p, and then the camera pulls some magic and tosses away some frames to make it 24p. Thus, while the actual data stream is 100mbs, only about 40 percent of that goes to make up the frames of the 24p output. (or 50% for 30p output). Is that how it works ?(obviously a simplification of how it really works).

Barry

Also will could she say if it always wrote at a 100mps or what ever the speed is.

I thought I read that she or somone said it always writes at a 100 no matter what. Some thought it'd write at 40mps since it would have to record the information that isn't used in the pull down.

But maybe they'll be some things revealed on April 4th unless we already saw the ad.

<<<-- Originally posted by Barry Goyette : Jan

I'm not sure. Let me phrase it the way it was put over at dvxuser...When shooting in 720 24p...are we really shooting 60p, and then the camera pulls some magic and tosses away some frames to make it 24p. Thus, while the actual data stream is 100mbs, only about 40 percent of that goes to make up the frames of the 24p output. (or 50% for 30p output). Is that how it works ?(obviously a simplification of how it really works).
-->>>

While I cannot disscuss how this camera works, I can discuss the concept of the data remaining in the DVCPRO HD signal once the extra frames have been removed. DVCPRO HD has 100Mbps at 60 frames of information. The compression on each frame is equal and the same, d optimized for the compromise of intraframe compression. If we look at the fact that there is 60 frames per second and there is 100Mbps, we have a formula. If we only use 24 of those frames, then we are using a little over 1/3 of the data or about 40Mbps. When working with FCP over firewire, you can reduce the data load from 100Mbps to 40Mbps just by casting off the exta frames.

Interestingly enough when working in DVCPRO50 and you remove the pulldown of 2:3:3:2 you are roughly at 40Mbps as well. Do these two look anything alike? No. The size of the image is much larger on the DVCPRO HD.

Does that help?

Best,

Jan

crystal clear...thank you for the explanation.

Barry

So what about the "PAL version" of DVCPRO HD? Will it still be 100mbs at 60fps or 100mbs at 50?

I guess it's about 83mbs, right?

It looks like Firestore support for this camera is very promising:

http://www.digitalvideoediting.com/a...e.jsp?id=31579

Linkified. Thanks, Brad. I need to add that press release to our own Articles section.

Interesting. Not having ever used P2, I would have assumed files would be stored in some more generic edit ready format. Do p2 files have to go through a conversion process after acquisition? That was one of my issues with HDV, that it wasn't immediately edit-ready (So I thought). I would have assumed random access media like the p2 would be even more edit ready. I don't want to have to do some conversion before I can edit. Guess it's up to the NLE's to support native MXF?

Or am I missing something here with the Firestore DV converter stuff? I hate waffly press releases that tell you almost nothing.

Aaron

The files are edit-ready with Avid editing systems, as they accept the mxf format natively.

The conversion suite referenced is a solid product ... that has been around unchanged for years.

The conversion process doesn't recompress or apply a codec, it just changes the file structure to meet the standards required.

GB

i'm as excited as you are 'bout this little beast..still my guess is it'll be max 7k..more like 5k

why?
looking at its body, it's clearly a consumer/prosumer cam even if it gives you superior quality. indy filmmakers make a small percentage of the sales of such cameras..usually it's the high-salery-geeks (lawyers, doctors, whatever) who just want's the latest and best equipment to film his daughter at the beach..he doesn't even understand 24p, 1080, datarate, compression, but if the salesman tells him it's the best he get's in the prosumer area, he'll buy it...still he probably wouldn't buy it at 10k thinking that's a stuff for the pros, not him

i also think small tv stations gonna favor the jvc cam, even if it'll have a lower quality..cheap tape..exch. lens..even me i'm kinda undecided

I like the idea of trying DVCPro, but I've always longed for the Canon Xl series wank factor. Now JVC have it, it's interesting, and they have more than the Canon, but of course the price will reflect this.

Aaron

It's neither of these Carmen.

If it were a consumer camera first and then adapted, then yes.

This is not the case.

It was designed and built by the professional/broadcast division of Panasonic. DVCHD Pro is not a consumer HD standard any more then HDcam used in CineAlta is. CineAlta and DVCpro HD are competing HD codecs. The Panasonic is a low end professional/industrial level gear.


Michael Pappas
http://www.Pbase.com/Arrfilms


<<<-- Originally posted by Carmen Stern :it's clearly a consumer/prosumer cam even if it gives you superior quality -->>>