4:4:4 12-bit Uncompressed DVX100

[Juan P. Pertierra]

Les,

1.)I'm not getting YUV from the CCD's, i don't think it has been claimed otherwise.

2.)The sustained rates for drives IS what i've been looking at. Right now, i am capturing RAW data clips continously on a WD EIDE drive that i bought two years ago. I can capture as long as i want and the data is free of errors and continous. I have tested continous raw video captures up to 15 minutes in length with no problems.

Juan

[Federico Prieto]

Jesus........What a Thread !!!!!!! I must confess I am wet !!!!!

Juan you are incredible...

[Ben Syverson]

<<<-- Also: look at the sustained transfer rated for hard drives, not the interface burst rates. Big difference. -->>>

Firewire doesn't have a burst rate -- you're thinking of a half-assed format like USB 2. FW400 is sustained 400mbits/sec, FW800 is sustained 800mbits/sec.

Granted, very few harddrives can max out FW400 (50 megabytes/sec), and I don't know of any non-RAID, out-of-the-box harddrive that can max out FW800 (100 megabytes/sec).

If you go to http://www.lacie.com/ you'll see that they have a bunch of cheap FW800 drives that can do anywhere from 55 to 88 megabytes/sec (a nice cushion for Juan's ~35MB/sec). Most pros I know prefer LaCie for high-speed Firewire applications; I know one guy who does uncompressed HD on a PowerBook over two FW800 buses using LaCie drives. He was saying that the LaCie drives were the only ones that could take it...

- ben

[Juan P. Pertierra]

Ben speaks the truth :)

I myself use the first LaCie FW800 drive that came out, a 200GB unit. Every benchmark i've run yields a ~70MB sustained write rate, which is more than enough what is needed for this application.

However, like I said, right now the system is not capturing to the Lacie drive but rather directly to a 120GB Western Digital WDC1200BB which i bought a long time ago. I haven't run any benchmarks, but it handles the continous writes perfectly.

I will be done with my finals on thursday afternoon, so i will finish writing the code to handle the blue frame strips and upload a clean clip in raw RGB frames....

I also can't wait to watch one of these clips uprezzed to HD on TV/projector....

Juan

[Stephen van Vuuren]

Ben:

Lacie does not manufacture hard drives or hard drive chipsets. All they are doing are getting IDE drives from Maxtor, Hitachi, Seagate and/or WD and putting them into an external enclosure with a firewire (and/or USB) chipset.

Any other manufacturer or user can do just the same with identical drives and firewire chipsets. Lacie has no properiatary technology to boost the speed of their drives (unlike Medea).

Lacie is just repacking components (doing it well, especially with their big drive series), but I just put a 500 GB RAID 0 setup in my computer using Hitachi 250 SATA drives for $390. The Lacie drive goes for $580. An external box (firewire, USB and/or SATA) with RAID chipset runs around $100 if you must have it external. As long as you pick the right chipset, you save almost $100 over Lacie plus Lacie only warrants drives and box for one year whereas my Hitachi drives come with 3 year warranties.

[Ben Syverson]

I'm aware that LaCie doesn't manufacture the actual drive mechanism.

However, an external harddrive is more than a drive mechanism and an Oxford chip. There's a lot of supplemental electronics, and it so happens that LaCie is very, very good with that electronics.

Their latest line (the "D2 Extreme") is far faster than their first generation FW800 drives, even though I'm pretty sure they were both based on the Oxford 922 chip, and used comparable drive mechanisms. Clearly, they've got a line on how to put together a drive.

But don't take it from me, talk to any video pro who relies on raw speed from the Firewire bus. If you're pushing the envelope, you're using LaCie...

- ben

[Stephen van Vuuren]

Well, I'm not a hard drive engineer, but a Lacie external drive only has three components: drive(s), a chipset (including the RAID0 bridge) and firmware. The extreme uses the Oxford 912 chipset for improved performance, not the 922.

I suggest you read this http://www.barefeats.com/fire44.html for more info. Note the Hitachi drives I just added beat the Lacie drive handily.

[Ben Syverson]

I'm not hard drive engineer either (and obviously get my Oxfords mixed up), but if you crack open a case, you'll see a drive and a board -- there's a lot more on the board than just a controller chip. I'm pretty sure LaCie designs their own boards.

I'm not generally given to brand loyalty/mysticism, but few friends and I have used LaCie for many years, and have never ever had a hard drive crash. Other friends have used WD, Seagate, Maxtor, Que, OWC, and they have all suffered catastrophic crashes. I know this is probably 99% what actual internal drive is used, but... there it is. Maybe it's just exceptional QA at the plant.

I must say, RAID is a whole separate issue, and you're comparing an internal RAID to an external one. To use a hated 80's phrase, "nuff said."

Anyway, this is OT...

- b

[Stephen van Vuuren]

Ben:

I'm glad you've never had a hard drive crash, but Lacie used the same WD and Maxtor drives you claim are unreliable. I've had and supported thousands of drives over the years, including Lacie and they've all crashed. Brand reliability varies between model, batches, runs and a lot of luck is involved with it.

A good warranty and good back is always best.

Per electronics, the board is just what holds the oxford bridge (and in models with RAID, the RAID controlller). Note all Lacie "Big Drive" and "Big Drive Extreme" are RAID models, they do not contain single drives.

The only big difference in an internal and external drive is the bus used (firewire vs ATA or SATA) - the setup, drivers and electronics are the same.

And this is very, very on topic as Juan's biggest hurdle (IMHO) figuring out a usable and affordable recording mechanism for the drive. I think that will be key to good sales of the unit.

I'm still a fan of SATA 2.0 (specs just finalized and released) as it allows the most flexibility and performance plus already is as low in cost and cross-platform. [url]http://www.serialata.org[/ur]

[Juan P. Pertierra]

Stephen/Ben:

To elaborate on this aspect of the project, i've looked at all the options, and here's what i've found.

The problem with SATA for this project is that afaik it was designed as a protocol for internal drives, so righ away i would have to solve encasing/power supply issues.

But most important of all, SATA requires special, very fast switching circuitry to implement, and I haven't found any hardware(i.e. IC's) that i can buy and use, already made for this purpose.

With firewire, buying an external FW800 drive already has an encasing and it's own method for powering it. Furthermore, it's slightly easier to obtain hardware that supports it, and for other technical reasons it is a breeze to implement in my case.

I felt that if i went with an internal drive, i would have to include it in the capture system encasing, and thus the user could not decide what size drive to use, not sure if that is a big deal...i guess i could have a mount on the bottom of the box such that you could mount it here, but then the tripod mount would be gone.

Furthermore, i don't think SATA cabling was designed to be long and as easy to deal with as a single firewire cable if the drive is to be somehow mounted on a shoulder bag.

I'm also thinking about implementing some sort of output to monitor the raw video...of course it won't be high quality, but it will allow to see the latitude and color of the raw footage for adjustments. This monitor output could be as simple as a standard analog S-video/RCA out, to an actual SDI or maybe separate YCbCr outputs...

Let me know what you guys think...i might be wrong about SATA because all i read was the low-down technical spec paper...but it seems like it's designed to be inside a computer rather than separate from the host and hanging from your shoulder :)

Juan

[Stephen van Vuuren]

Juan:

SATA II parts might be a harder to come buy right now but already a number of external SATA 1 parts on the market.

http://www.extremetech.com/article2/...1546751,00.asp is one and there a plenty of DIY kits, including ones that use Firewire for the connector but SATA drive. Note that no drives are Firewire or USB native, they are IDE or SATA or SCSI (or Fibrechannel if you have the bucks) - this is the key advantage SATA has.

The specs for SATA II are here: http://www.serialata.org

I except by mid 2005, SATA will have 50% of the drive market or more.

A transition plan may be to go with SATA drives in firewire enclosures and then SATA drive in SATA enclosures as parts and costs allow. Perhaps offer bpth flavors.

[Ben Syverson]

SATA may get 50% of the internal drive market. But it will have under 10% of the external market.

Firewire is the monster in the external market right now, and that certainly won't change by mid 2005.

- ben

[Stephen van Vuuren]

Ben:

It's only a monster in the Mac market which is well under 5% of the worldwide PC market.

USB 2.0 has already outpaced firewire for external devices, including drives. Only SATA II could change that, not Firewire 800.

Of course, probably near 100% of DV cam users have firewire 400, but only G5 users and handful of others have firewire 800.

That's why I think a SATA drive in a firewire enclosure is probably the best short-term solution followed by a SATA 2 solution. When PC's come standard with an external SATA II port.

Of course, the ultra high speed wireless USB could be interesting too when it debuts.

[Ben Syverson]

"When" PCs come with external SATA II ports? PCs come with USB2 and FW ports right now -- the installed base is massive. 2005 is practically tomorrow, and the spec for SATA II isn't even finalized yet. It's an RC, and after that there will be other standards applications. If SATA II ever becomes a standard port, it won't be for at least 18-24 months.

And let's not even get into the Mac issue -- is this not dvinfo.net? I wonder what the percentage of out readers are Mac users -- if it's not a majority, it's probably close. Firewire is a monster not for Mac users, but for all video/media creators. SATA is great for internal storage, and interesting as a possible external solution, but let's not get ahead of ourselves. FW800 is awesome, it's already on a huge number of machines, and it works now.

As for USB2 outpacing FW, well, history shows that there's no stopping PC users with their hearts set on an inferior technology. But I imagine that if you look at external drives that run at or above 7200rpm, it's not so clear cut.

- ben

[Stephen van Vuuren]

Ben:

I see we difffer on this - however, I think your view of the storage market is incomplete and not based on actual sales numbers - a quick google does not seem to back up your points.

While you may be comfortable with Firewire 800, the actual market conditions seem to point in other directions.

Juan needs to probably rely on better experts than you or I in making a decision about market factors and interfaces.

However, SATA II is a final spec (http://www.internetnews.com/storage/print.php/3339821 & http://www.intel.com/technology/serialata/ahci.htm
and expect to see it plenty later this summer and full swing by fall.