After some deliberation I have decided to opt for a MiniDV camcorder as
opposed to the new DVD models.

I have read about keeping a full quality MPEG-2 version of footage on my PC,
as well as the compressed version which is ultimately burned to DVD for
distribution, and generally reference is made to FireWire.

If necessary, I will purchase a FireWire card, but is it not possible to
transfer what's on the MiniDV tape to the PC via USB 2.0? Some camcorders
have this, and my PC already has this. I always thought that USB 2.0 and
FireWire are comparable standards.

However, it seems to be implied that you can "stream" video using FireWire,
but not USB. If this is the case, what is the USB output on these
camcorders for? Is it for transferring stills only?

Thanks for any input.

Tanel.

On Sun, 26 Jun 2005 10:52:22 +0100, "Tanel Kagan"
wrote:

After some deliberation I have decided to opt for a MiniDV camcorder as
opposed to the new DVD models.

I have read about keeping a full quality MPEG-2 version of footage on my PC,
as well as the compressed version which is ultimately burned to DVD for
distribution, and generally reference is made to FireWire.

If necessary, I will purchase a FireWire card, but is it not possible to
transfer what's on the MiniDV tape to the PC via USB 2.0? Some camcorders
have this, and my PC already has this. I always thought that USB 2.0 and
FireWire are comparable standards.

However, it seems to be implied that you can "stream" video using FireWire,
but not USB. If this is the case, what is the USB output on these
camcorders for? Is it for transferring stills only?

The USB output is for whatever the camera designer has decided to
implement :-)

I believe there are a few cameras which support streaming video over
USB. If yours does, the manual will make it quite clear.

Generally, FireWire is used for streaming video. Editing programs
look for a FireWire input. If there is also a USB port, this is used
for still picture transfer.

I suspect this has more to do with the features of generally available
microchips than with any particular design decision. Motorola (or
someone) make a chip that supports DV functions and outputs FireWire
protocol. So the camera makers all use that chip. There's another
chip that handles still picture functions. This one outputs USB. One
of them goes in too. Perhaps the next chip will integrate both
functions and have a choice of output. We'll know when all cameras
start offering these features.

Luckily, a FireWire card is cheap. Dabs used to do one for under
£15, including a cable. (This was in the days when FireWire was quite
new, and Maplin etc. were asking that much for the cable alone!).
I'm not sure if that deal is still going, but you won't have to pay
much more.

In message , Tanel Kagan
writes
After some deliberation I have decided to opt for a MiniDV camcorder as
opposed to the new DVD models.

IMHO the best choice. Unless, of course, you have no intention of ever
doing any editing of your video and simply want to view your video, as
taken, on your DVD player.

I have read about keeping a full quality MPEG-2 version of footage on my PC,

MPEG-2 is not "full-quality". It is compressed and of a lower quality
than the DV of your camcorder, the quality depending on the degree of
compression used or set by your software (i.e the resampling bit-rate).

as well as the compressed version which is ultimately burned to DVD for
distribution, and generally reference is made to FireWire.

VOB files (the files that actually contain the video and audio on a DVD)
are essentially MPEG-2).

If necessary, I will purchase a FireWire card, but is it not possible to
transfer what's on the MiniDV tape to the PC via USB 2.0? Some camcorders
have this, and my PC already has this. I always thought that USB 2.0 and
FireWire are comparable standards.

Not quite true. Firstly a bit of background. The basic IEEE1394 firewire
standard is extended by a trade association to give standards
generically known as IEEE1394TA which allow firewire to be used for any
particular application. In the context of camcorder application(s),
there is a superset of 1394 adopted by all the miniDV camcorder
manufacturers. There is no equivalent trade association (and standard
superset) for USB2. In the context of camcorders, the IEEE1394TA adds
control and monitoring protocols to the basic 1394 standard. These
extensions are effectively "set in stone" - but only for firewire (and
not for USB2).

The other significant difference between 1394 and USB2, is that 1394
runs at 400Mbps (and no slower). If bits (or more accurately frames) are
lost, they remain lost - there is no "send-again" mechanism. USB2 is a
"step-down" transmission protocol, where if bits (or frames) are lost
the speed steps down. It's not unusual for USB2 to step-down to a speed
which may not be high enough for the transfer of video.

However, it seems to be implied that you can "stream" video using FireWire,
but not USB.

I'm a little uncomfortable with the word "stream" in this particular
context (see below).

If this is the case, what is the USB output on these
camcorders for? Is it for transferring stills only?

In the main yes. USB is also (often [1]) used when using your camcorder
as a webcam. This is the context where the word "stream" is more
appropriate. A typical application is Microsoft Messenger.

[1] I can't speak for all manufacturers/models, but Sony
camcorders released in the last 12 months all allow
USB streaming for webcam operation. Earlier models may
not.

There's one more issue which is significant. All video editing and
capturing software supports IEEE1394, but there is no guarantee that any
particular software will support USB.

So in a nutshell, I'd suggest that you stick to IEEE1394 for video, and
(if you must [2]) USB for transfer of stills.

[2] I prefer to use a memory card reader to transfer stills,
but that's quirky me :-)

--
Tony Morgan
http://www.camcord.info