View Full Version : Can it shoot 60p?


Hse Kha
November 6th, 2005, 09:01 AM
Hi,

Does the JVC GY-HD100 shoot 60p? I ask because the older JVC one only shot 30p.

If so, is there a place on the internet where I can download some 60p m2t clips?

Thanks.

Stephen L. Noe
November 6th, 2005, 09:33 AM
480p60 is available. You can browse over to JVC's web site and download the brochure. Also the user manual is available at the top of the threads for you to download and get specs.

David Newman
November 6th, 2005, 10:55 AM
Does the JVC GY-HD100 shoot 60p?

Yes it shoots full res. 1280x720 @ 60p, but not to HDV tape. The component outputs have a full 60p signal on them, which can be digitized for editing 60p or 2.5X slowmotion over 24p. It is pretty cool. I have written more about this here : http://cineform.blogspot.com/2005/10/jvc-hd100u-frame-rates.html. You will need a HDSDI/component recorder to do this.

Hse Kha
November 6th, 2005, 11:50 AM
David,

Nice blog.

It seems weird that it can't capture 60p to HDV. Surely a standard for HDV is 720p/60, no?

Anyway so does your company make something to catpure the uncompressed SDI out of the JVC/Canon XL-H1?

Thanks.

Stephen L. Noe
November 6th, 2005, 03:07 PM
David,
It seems weird that it can't capture 60p to HDV. Surely a standard for HDV is 720p/60, no?

miniDV tape can't handle that amount of data....

Hse Kha
November 6th, 2005, 05:43 PM
miniDV tape can't handle that amount of data....

HDV can handle 25Mbits/sec of MPEG-2. Fox and ABC boradcast it at well under that!

Besides data wise 720p/60p (1280x720x59.94) is only 18.5% more than 1080i/60i (1440x1080x29.97).

So why not??? A shame...

Barry Green
November 6th, 2005, 09:27 PM
It seems weird that it can't capture 60p to HDV. Surely a standard for HDV is 720p/60, no?

Yes, 720/60p is in the HDV standard. JVC's own GY-HD7000U lists 720/60p as one of its recording modes.

But the HD1, HD10, and HD100 don't support it. It may be because the hardware MPEG encoding chip can't handle that much data.

miniDV tape can't handle that amount of data....
Sure it can. The HDV spec calls for 720/60p at 19 megabits, the exact same data rate as the current 720/30p. The hangup is the encoder chip, not the tape format.

Steve Mullen
November 7th, 2005, 01:27 AM
The hangup is the encoder chip, not the tape format.

Bary's right -- the only thing that has to be done is drop a 2X faster encoder into the HD100. But, that 2X will dramatically increase power consumption and heat -- so we may not see the encoder except in a bigger camcorder.

Of course, perhaps the current chip can do it -- but currently only a small percent of the production run can realiably run at 2X. We could imagine that as production ramps up, we could see a premium priced HD200 that offers 720p60. ($9999) This would not be a REPLACEMENT, but an augmentation of the line.

I keep wondering why only one channel (#1) is recorded as PCM audio. Do we get the second channel when the faster encoder appears? I can't think why these two issues would/could be related, but we have seen that as DVCPRO25 went to DVCPRO50 by using dual compressors, the number of audio channels recorded doubled. Food for thought.

My sense has always been that 720p60 is a lot closer than folks think. I don't think JVC will let Panasonic have more than a few months run of 720p60. In fact, it would be a nice move to announce 720p60 the day before the P2 ships.

Stephen L. Noe
November 7th, 2005, 06:46 AM
Sure it can. The HDV spec calls for 720/60p at 19 megabits, the exact same data rate as the current 720/30p. The hangup is the encoder chip, not the tape format.
You are right, I am wrong. I originally meant in the context of the HD-100 as it sit's now.

Werner Wesp
November 7th, 2005, 10:03 AM
It would also mean they'd have to go for longer GOPs and higher compression to keep the datarate down, and that wouldn't be a good thing for video-quality....

Thomas Smet
November 7th, 2005, 10:26 AM
It would also mean they'd have to go for longer GOPs and higher compression to keep the datarate down, and that wouldn't be a good thing for video-quality....


That would be the tradeoff I guess.

30p at high quality

or

60p at a little bit lower quality

Some users or projects may want higher quality and do not care as much about 60p while other users may need the 60p no matter how much compression is added.

Even though 60p may not be as clean remember that 720p broadcasts are at 60p and still under 19 Mb/s.

Speaking of that does anybody know what GOP length a typical 720p 60p broadcast uses?

David Newman
November 7th, 2005, 10:27 AM
>>It seems weird that it can't capture 60p to HDV. Surely a standard for HDV is 720p/60, no?

It seems that many of the responses have answered this. I agree that is an encoder issue, and the HDV standard does allow for 720p60.

>>Anyway so does your company make something to catpure the uncompressed SDI out of the JVC/Canon XL-H1?

The Wafian recorder that we used for the JVC HD100 will also capture all the video modes from the Canon XL H1. The unit is designed for all standard HD resolutions 720p (up to 60p) and 1080i/p (up to 30 frame per second.)