View Full Version : DVCproHD recorded on HardDisk?


Federico Martini Crotti
September 22nd, 2005, 09:07 AM
Two threads have derived onto this very important topic. I thought I'd join them in one. Hope this isn't crossthreading. Apologies if it is.

I'd be great if Jan could shed some light:

The HVX200 records DVCproHD on to the P2 flashcards (2, 4 or 8 GB).

Is it impossible to think of a P2 (that would function only as connector) with a short cable out to an external hard disk (100 or 200 GB) and record much more DVCproHD?

FireWire 400 seems too slow. FireWire 800 maybe? SDI? These faster connections don't come with the HVX200 and it's late to ask for them, but I wonder if the P2 slot would allow for someone like FireStore to develop what I described above.

Jacques Mersereau
September 22nd, 2005, 09:26 AM
Yup, that idea has already been floated on this board . . . somewhere.

Whose idea was it again?

Federico Martini Crotti
September 22nd, 2005, 09:47 AM
Well, someone is proposing the FireStore as it is now, with FireWire 400, but somebody else said it was too slow.

Barry Green
September 22nd, 2005, 12:28 PM
The existing FireStore would never be able to handle the data rate -- it only can do about 40mbps. It would take a newly-designed unit specifically engineered to handle the 100mbps data rate. And FocusInfo has announced that they are developing exactly such a product.

FW400 can easily handle the DVCPRO-HD data rate. Heck, FW100 could handle it -- it's 100 megabits, and FW400 can handle four times that data rate.

As far as the product you're talking about (basically a card that plugs into a P2 slot, has a hard drive controller on it, and a 1394 or USB2 connection for an external drive) -- I know of at least one independent company attempting to develop exactly that. There may be other efforts underway as well. I'm sure we'll see such a product supplied by a third party company, probably not long after the camera's introduction.

Federico Martini Crotti
September 22nd, 2005, 12:42 PM
If FW400 isn't the problem, where does the existing FireStore fail to handle 100mbps? In writting to disk?

Jacques Mersereau
September 22nd, 2005, 02:04 PM
Hey, check this out!!!! This could be the anwser to all our dreams
of a portable near uncompressed HD DVD recording!

http://videosystems.com/e-newsletters/HD_Disc_Contenders092205/

Barry Green
September 22nd, 2005, 02:42 PM
If FW400 isn't the problem, where does the existing FireStore fail to handle 100mbps? In writting to disk?
It's most definitely not a problem with FW400, because there are already working systems today that edit DVCPRO-HD over FW400 (the FCP-HD system using an AJ-HD1200A deck being the first notable example).

I would guess the 40mbps limitation is probably something to do with the hard disk they're using. The smaller your hard disk (in diameter), the slower they are. 3.5" drives are way faster than 2.5", which are way faster than 1.8", which are way faster than 1", etc. So I don't know what kind of drive the FS is using internally, but if it's a 4200rpm 1.8" drive, there's no way it'd be fast enough for DVCPRO-HD.

Seagate has just announced their 2.5" "Momentus" line of hard disks, and those have record-setting performance, and even those are just barely fast enough to support the 14 megabyte per second transfer rate, with any degree of margin of error. Look at the chart at
http://www.tomshardware.com/storage/20050822/momentus-05.html

There you'll see various 2.5" hard disks compared. Look at the "minimum sustained write speed" -- That Fujitsu is just barely, barely enough, and asking a drive to perform at that speed over the entire surface of the drive in one continuous record operation is probably asking too much (if you want a reliable solution, that is). So the new Seagate may be what they're going with; they have a 20 megabytes per second sustained rate, which should be enough for the 14 megabyte data rate of DVCPRO-HD with enough of a margin of safety to ensure no dropped frames.


I wouldn't be surprised at all if part of the reason the FireStore for the HVX has a March shipdate turns out to be that they're waiting for an even faster, more affordable hard disk to be developed.

Erik Albertsen
September 22nd, 2005, 02:57 PM
As far as the product you're talking about (basically a card that plugs into a P2 slot, has a hard drive controller on it, and a 1394 or USB2 connection for an external drive) -- I know of at least one independent company attempting to develop exactly that. There may be other efforts underway as well. I'm sure we'll see such a product supplied by a third party company, probably not long after the camera's introduction.

That sounds jolly good !
I wonder who's going to let go of 2K for a 80 GB Firestore ?

Thomas Smet
September 22nd, 2005, 03:27 PM
There still isn't going to help the event market very much. A 80 GB drive will only fit 80 minutes of the highest DVCPROHD video. Since the drives are built into the firestore you will end up having to buy 2 or 3 of them for longer recording times as well as for backup in case one of them breaks. You would almost be better off getting a cheap laptop and a couple of P2 cards and hire a person to go with you and swap cards throughout the day.

Federico Martini Crotti
September 22nd, 2005, 05:18 PM
I always thought it was weird how DV was used for everything: from a feature film to home movies. We seem to be getting more specialized formats now. Uncompressed for the rich corporations, DVCproHD seems fine for independant live action on a budget, even scripted documentary. HDV seems very fine for events and unscripted documentary. DV, extremely fine for home.

Jan Crittenden Livingston
September 23rd, 2005, 09:54 AM
Hi,

Several thoughts about this thread.

1. Uncompressed recording needs to be able to record 1.2Gbps, this has to be an array of some sort. DVCPRO HD is compressed, but then so are all HD camcorders. Taking an HD-SDI out of the side to an uncompressed recording of will require something that is not necessarily mobile. Taking HDSDI out to a DVCPRO HD machine is the same as using the HVX200 unless you are using some other camera which does not have true 24P. Going 1394 to the upcoming FS100 is the hard drive solution that will record the DVCPRO HD native recording without the P2 Card.

2. HD-DVD vs Blue-ray, both are very compressed. DVCPRO HD is 1 GB per minute, and these are 23GB or 25GB per side, yet hold 2 hour HD quality movies. I think they are compressed.

3. Compression can be a friend, it allows for certain things to happen like camcorders that can stand on their own.

4. If you do not embrace IT, then the HVX200 is not for you. If you think you can approach this camera with the "tape" think workflow, then you will be unhappy. However, I feel that if given the thought, that many folks could indeed make this work. The feature set of the camera are such that it might invite the rethinking necessary to make it work.

5. For the event guys, the Focus Enhancements FS100 will have 100 GB of storage. If it were me and I was shooting the event, I would shoot it in DVCPRO50/24P or 30P and upconvert to HD later. This looks pretty darn nice. If you haven't seen Paul Reiser's film, "The Thing About My Folks" check it out. This was done with the SDX900 and then bumped. But to finish that thought it would give you 200 minutes of record time. I know that Avid and Apple have upconversion programs that are very good. And I am sure there are many others.

Best,

Jan

Edwin Hernandez
September 23rd, 2005, 10:43 AM
Hi,

5. For the event guys, the Focus Enhancements FS100 will have 100 GB of storage. If it were me and I was shooting the event, I would shoot it in DVCPRO50/24P or 30P and upconvert to HD later.



A- Is it 100 minutes in 1080i or 720p?
B- Will the upconversion retain the quality or will it pixelate as when you apply a digital zoom?

-EDWIN

Barry Green
September 23rd, 2005, 01:15 PM
A- Is it 100 minutes in 1080i or 720p?
It'd be 100 minutes of 1080i, 100 minutes of 1080p, or 100 minutes of 720/60p. If you're talking about 720/24p, it could deliver up to 250 minutes, or over four hours of high-def 24p footage (if it only records the "active frames"). If you want to shoot events in high-def, with the filmlike 24p look, 720/24p on the FireStore should give you four hours of storage (provided that the FireStore saves only the active frames; I don't know for sure that it will).

Will the upconversion retain the quality or will it pixelate as when you apply a digital zoom?
Depends on the method used to upconvert. I've scaled DVX standard-def footage up to high-def 720p resolution and it looked very, very, very clean. I wasn't able to take it all the way to 1080 satisfactorily, but other resizing algorithms may be able to do so.

John Mitchell
October 10th, 2005, 09:52 AM
Hi,


2. HD-DVD vs Blue-ray, both are very compressed. DVCPRO HD is 1 GB per minute, and these are 23GB or 25GB per side, yet hold 2 hour HD quality movies. I think they are compressed.


Jan

Well actually Blu Ray has already announced plans for a 100GB and 200GB disk , but no one has actually settled on a data rate or format yet (although I'd be betting somewhere around 54 M/bs HD-DVD, but Blu Ray will support a minimum of 1.5x that). The disks you refer to are the single layer format not the newer dual layer disks being proposed - from memory they've already been demo'd at 50GB/side.

Here's a table that compares the two formats:

Look at 3.2:

http://www.blu-ray.com/faq/#1.5


However one thing to keep in mind - although we will be looking at a more highly compressed stream, we won't be talking about live acquisition - HD will be multi-pass encoded to tweak the absolute max out of the MPEG stream. I don't know enough about DVCProHD to comment - however I doubt the codec is as efficient as MPEG4 AVC being proposed by both organisations.

So in summary the two formats should compliment each other nicely - an easy to edit capture format @ 100Mb/s versus a more refined replay format @ either 33Mb/s or 54Mb/s. Should be a marraige made in heaven...
John