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Old Nov 28, 2004, 3:23 PM   #1
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Electronic techy here , need both VID and DIGICAM . I was surprised to

see DIGICAMS that output full speed MPG thru USB 2.0 ( 480Mb/s) .

So why buy a VIDEOCAM !!!Use a DIGI to make movies .

Unfortunately the masses can't get their hands on a storage

medium ( port DVD or HDD ) .

Some people can cobble together a home made battery pack and

do the interface . But i wish i could buy it rather than build it .

Any tech' oppinions ?




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Old Nov 28, 2004, 3:47 PM   #2
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Paul-Jones wrote:
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Electronic techy here , need both VID and DIGICAM . I was surprised to

see DIGICAMS that output full speed MPG thru USB 2.0 ( 480Mb/s) .
They don't. Video must be stored on themedia in the camera (Memory Stick, CompactFlash, Secure Digital, xD Picturecard, etc., depending on what type the camera uses).

The USB port is used for transferring stored video (and still pics) to a PC later.

BTW, you're not going to find a device that outputs at full USB 2.0 speed, either. I am not aware of any model that comes anywhere nearUSB 2.0 speed during transfers (480 mbits/second, which is60 mb/second since there are 8 bits in a byte). Most will top out at about 1/10 or less of the potential USB 2.0 speed (due to media speed, hardware limitations, etc.).

480 mbits/second is onlythe theoretical maximum, and does not reflect real world equipment capabilities.

In any event, movie lengths on a Digital Still Camera are limited to the size of their media (and many models have length limitations, regardless of what size media they have installed).


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Old Nov 30, 2004, 12:00 PM   #3
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orig post They don't. Video must be stored on themedia in the camera (Memory Stick, CompactFlash, Secure Digital, xD Picturecard, etc., depending on what type the camera uses).

-------------------------2nd person's reply-----------------------------------

At worst you simply buy a notebook or portable mass storage device

thats millions of times larger than mem stick ! My buddy got

a 2.5" HDDyears ago to store his images ( but unfortunately no video)

But todays notebooks will accept USB at video rates ( USB 2.0) , so he

can now do both if he does a notebook .

There is a WAY ! You just gotta look ! If you don't like the weight

penalty .... figure how you can cobble or make a very low power

IDE 2.5" HDD to take streaming video from your DIGICAM that's

outputting at VGA 30fps .

This is available TODAY . There have been many 2.5" HDD interfaced

to DIGICAMS , you just gotta look around .

The reason i don't own one is i want better . I want small size

cheaper HDD and battery packs . I want to pay $60 for a lite wt

40GB 2.5" HDD w/ 1800 maH pack that last 3 hours .... all for $60 !

------------------------------ Orig post -----------------



The USB port is used for transferring stored video (and still pics) to a PC later.


------------------ 2nd person's reply--------------------------

True but you are not up to date ! The USB port is VIDEO rate ! So why limit

it to delayed VIDEO ? Remember , we're not vu'ing the video on notebook ,

we're only storing it at DIGICAM rate , to be edited/improved and later

burned to DVD and THEN vu'ed at a higher frame rate and edited for better

quality .



------------- orig poster ---------

BTW, you're not going to find a device that outputs at full USB 2.0 speed, either. I am not aware of any model that comes anywhere nearUSB 2.0 speed during transfers (480 mbits/second, which is60 mb/second since there are 8 bits in a byte). Most will top out at about 1/10 or less of the potential USB 2.0 speed (due to media speed, hardware limitations, etc.).

480 mbits/second is onlythe theoretical maximum, and does not reflect real world equipment capabilities.

--------- 2nd person's reply--------------------------

You are confused . USB 2.0 IS 480 megabits / sec ..... Thats a fact jack .

Expect FIREWIRE to die !

This IS video rate . You CAN transfer VGA 30fps to a HDD thru a 2.0 interface .

Real people ARE doin MPEG at USB 2.0 rates .

The DIGICAMS DO output at 30fps , VGA , go read it ....



No , it can't be done , we can't do it , it's too expensive !!!

Dragged into the future , kicking and screaming ...........


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Old Nov 30, 2004, 12:33 PM   #4
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LOL

Yes, USB 2.0 is 480 mbits/second (your original post said 480 mb/second, which means bytes not bits). There are 8 bits in a byte, so USB 2.0 has a theoritical maximum of 60mb/second (60 megabytes/second).

Yes, this is plenty fast enough to support 640x480 video at 30fps (or even higher resolution and faster frame rates -- once the hardware in the cameras catches up to what is possible over USB).

But, the digital stillcameras on the market today do not do live video via USB this way. You write it to the camera's built in media (with sizes up to about 4GB or so available now from a practical cost perspective, although you can get larger ones -- and these will keep getting even larger and less expensive), then transfer the files to your PC later via USB.

As far as transferring the video to a largerdevice in the field,there area number of portable storage devices available that are designed to let you transfer the stored images and video to them when your memory cards are full (these contain laptop hard disk drives, CD writers, DVD writers, etc.). Of course, you can carry spare memory cards with you, too.

You'll find reviews of some of the portable storage device models under the accessories reviews menu choice on the main page. Here is a direct link:

http://www.steves-digicams.com/digi_...s.html#storage


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Old Dec 1, 2004, 5:21 PM   #5
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The 480mbps or 60mBps is only a burst rate. The actual transfer rate is based on other things. Judging by the choppy ness of the lcd viewfinders, i would say that 16fps may be pushing it.
(edit) I don't know why everybody is down on firewire it is currently 800mbps, and will in the foreseeable future be 1600mbps. Plus with the increased efficiency, it outperforms all of the usb2.0 hardware i have.
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