View Full Version : JVC NAB Press Releases
Adam Letch April 26th, 2006, 05:34 AM but, keeping in mind they want to keep data rates down, but keep best quality for hdv, what about something like 4:2:1 compression, thus keeping data size down, but getting further quality enhancements, and that could max out at maybe 30mbps?
I'm sure someone will inform me thats its not possible, but just a thought. eg: new Sonys goto 35mbps vbr.
Wayne Morellini April 26th, 2006, 07:07 AM Steve@ While I am sure a studio based HD converter can do good work with 19Mbps and 720/60p I am not so easily convinced of an encoder that has to fit into this camera, run of batteries so not consume too much power (which brings up an interesting question about battery life with these new models vs the HD100), dissipate the additional heat (which is the root of all evil with SSF) and most importantly do it all in real time. I haven't seen a lot of HD TV broadcasts but I do know that when I have watched live events like sports, they are far from the quality I would accept. The proof will be in the pudding and I will become more of a believer when these cameras are in real users hands and real world usage reports come in, not just because of JVCs press releases. Surely there is no question 30p can be encoded at a higher quality than 60p with the same data rate. So the question remains, how much of a compromise over 30p WRT compression quality is this 60p implementation? [If they can do 60p in 19Mbps, why not 30p 4:2:2?]
PS: Why would JVC not use the extra 6Mpbs anyway? It could only serve to improve the quality wouldn't it? Straight to HDD though they could use any bitrate they want. Tape seems to make it all too hard ;-( We still arn't getting that PCM audio yet are we?
.
Processing power has advanced so much that it probably wouldn't be a problem. For instance, the Ambarella h264 codec chip does over 15Mb/s+ h264 on an internal array of many Sparc processors, not much power, around 1w for the pro version (and I don't know how far over 15Mb/s the pro version is). Anyway, such a thing should be able to be easily changed for top Mpeg2, even the consumer versions that work at 100's of mw. Personal, I would prefer if they did h264 19mb/s+ for all modes. Does anybody know for certain if it is mpeg2 or what data rate?
I am very interested in this camera myself, what codec it uses and what data rate (apart from sensor improvements etc).
About the usefulness of 60p:
I read something about European HDTV looking at 50p 720p for sports, rather than 1080i, in the news releases of IBC last year, or the year before. So I wonder if that has something to do with it.
Thanks
Wayne.
Jeff Morrissette April 26th, 2006, 07:22 AM I was die hard looking for the canon h-1 but I don't feel comfortable with 1080i for certain type stuff.
I think the 720 rocks. Much more "robust" (right word?)
I totally agree with the 24p pan issue. I love 30p. But I really like the idea of pulling a great slomo with 60p.
Can you convert 60p to 30p? Get the option of both film look and a great slow shot.
Andrew Young April 26th, 2006, 08:33 AM Can you convert 60p to 30p? Get the option of both film look and a great slow shot.
Hi Jeff,
You can change to speed of a 60p clip to 30p or 24p using a program like Cinema Tools, which gives you a longer clip (slow mo), or you could drop every other frame of a 60p clip to convert it to 30p and maintain real time (by placing it on a 30p timeline in FCP). The only reason why you would do the latter, however, is if you thought you were going to do slow mo but then decided to use the shot as real time (and 30fps was your time base). Of course, your shutter speed will be twice as high, so the look will not be exactly the same as if shot in 30p.
By the way, Cinema tools does not at present work on MPEG clips, which means to do slow mo you will need to convert your clips to Apple Intermediate Codec.
If you're thinking of using a lot of slow mo, consider using 24p as your time base. That way you can achieve a 2.5x slow down rather than just a 2x slowdown.
John Mitchell April 26th, 2006, 08:59 AM 2.5" HDDs are pretty dam tolerant with operating shock, and they are quite small as well. SATA 2.5" drives also adds hot swap capabilities.
Worried about reliability, simply add two slots like P2 and load a HDD in each. Mirror the data as you write it to both drives. More chance you'll break your camera than have 2 drives fail together. All this would easily fit into the area currently consumed by the tape transport etc.
Guy read the posts on the tapeless forum - we are not talking about pure hard drive reliability here, we are talking bout the reliability of the implemented solutions - and so far few are brave enough to shoot without tape and of those that have, many have had their fingers burnt. The problems are not solved by mirroring either - these are software glitches, firmware problems, power problems - these devices just aren't as reliable as tape in the field, yet.
BTW the reports that have come back on the DR-HD100 to date look very promising, but if I was a camera manufacturer I simply couldn't risk a hard drive only solution on an industrial or pro camera.
Jeff Morrissette April 26th, 2006, 10:26 AM Thanks for that 24p slowmo idea. Totally overlooked that one, will have to try it.
Greg Boston April 26th, 2006, 10:37 AM BTW the reports that have come back on the DR-HD100 to date look very promising, but if I was a camera manufacturer I simply couldn't risk a hard drive only solution on an industrial or pro camera.
That's part of what is steering me towards XDCAM and blu-ray. You have to drop the camera from several feet to the ground just to get it to skip, but by then your camera is toast anyway. It has proven reliable under pretty grueling camera rides.
-gb-
Tim Holtermann April 26th, 2006, 11:20 AM Just got back from NAB.
HD200 - same as HD100 but with 60P and a "Flip" option for flipping the image before recording to tape when using an adaptor like the RedRock. Price increase - 2K.
HD250 - same as HD200 but with HDSDI, more synch options. Another few K.
3 new lenses. One Canon prototype, 2 Fujinon. One of the Fujinon has a list price of 3500K was almost like the stock lense (maybe a tad wider) but much better glass. Impressive.
Also: Don't forget that tapeless is already here with the HD recorder. The plus to this camera over other non-tape based recording is that you can still record to Tape at the same time as the HD. Therefore you have an instant backup of your footage and another level of redundency.
K. Forman May 16th, 2006, 11:45 AM I've been looking at the HD200, but haven't noticed if it can burn a time code. Can it?
|
|