Capture via USB2 instead of FireWire?

[cosmin]

Hi,

I need to capture DV video from my Panasonic GS-250 camcorder onto a laptop which has USB2 ports, but not FireWire. Is this possible? If yes, how?

So far, I tried using the software that came with the camcorder, and I also tried Adobe Premiere 6.5. Both of them were expecting a DV device, which obviously did not exist. But I could not convince either of them to try to look for the camcorder via USB2, even though I installed all the USB-related drivers that were found on the manufacturer-supplied CD.

Am I missing something? If these programs cannot capture DV-AVI via USB2, is there any other capture software that can?

Best regards

[hech54]

Doubtful.
You may get VCD quality at best....IF it can be done.
Normally USB is for the snapshots on the tape and firewire is for the video.

[guns1inger]

It can only be done if the camera also supports DV avi transfer via USB2. Some of the newer ones do, but most don't. Those older cameras that do support video transfer via USB only transfer a low res, highly compressed video, not DV quality.

If you have PCMCIA slots on the laptop then you could get a DV port on a card so you can transfer DV avi via firewire, otherwise you may be SOOL.

[gastorgrab]

DV avi transfer via USB2

Check it out for yourself......

USB Video Class (UVC) Driver for WinXP
http://support.microsoft.com/kb/899271/en-us

UVCView – Diagnostic Tool for USB Video Class Hardware
http://www.microsoft.com/whdc/device/stream/vidcap/UVCView.mspx

A description of the standard
http://download.microsoft.com/download/5/b/5/5b5bec17-ea71-4653-9539-204a672f11cf/USBVid-ext.doc

Miscellaneous documentation
http://www.usb.org/developers/devclass_docs/USB_Video_Class_1_1.zip
.

[guns1inger]

Never said it could not be done, I know it can. But most cameras and devices do not support it. Most cameras that ship with USB connections are designed to only transfer low quality (sorry, email quality) video though this port, and still require a firewire port to transfer full DV video.

[KBeee]

WMM will "see" either USB2 or Firewire for transfering from camera to PC, but as guns1inger has said, it's only practical if your camera supports proper USB2 transfers. I know the GS 400 does, but I have a feeling that the GS250, and GS150 don't.
You'll have to read the manual for your camera to check, or just try it out with WMM and see.

[gastorgrab]

Never said it could not be done, I know it can.

The only thing i was suggesting is a place to find more info if cosmin wanted to persue the matter further.

I was just tryin' to help.
.

[cosmin]

Many thanks, everyone, for your useful answers!

The thing is, I do know that classic USB (i.e. USB version 1.1) does not have enough bandwidth to transfer the DV data at full quality. On the other hand, USB2 has higher bandwidth than IEEE1394: compare 480Mb per second (USB2) versus 400Mb per second (IEEE1394a). For this reason, I am surprised to learn that there's trouble transferring the native DV data via USB2 in full.

Best regards

[redwudz]

That's USB 2.0's stated bandwidth, but in real life FireWire is quite a bit faster and better for large file transfers. But either interface is faster than DV needs. This article explains it better: http://www.pcworld.idg.com.au/index.php/id;1847886895

What About USB 2.0?

In the not too distant past, there was a clear distinction between USB and FireWire. USB 1.1 could not transfer high quality DV; loosely defined as 25 frames per second (fps) with each frame being 640x480 resolution, due to USB's transfer limit of around 11Mbps (or around 1.5MB per second). Transferring DV requires a transfer rate of at least 3.6MB per second, which left FireWire as the only option due to its ability to work at 400Mbps, or up to around 50MB per second. Then along came USB 2.0 with a transfer rate of 480Mbps or around 60MB per second.

At first glance it would appear that USB 2.0 is even faster than FireWire; however speed is not the only issue when it comes to DV. One serious issue with USB 2.0 is that it can not guarantee a specified data transfer rate. This is due to USB 2.0 being a master-slave technology, which means it needs a computer's CPU to coordinate the appropriate data transfers. While not a problem when dealing with low demand peripherals such as Web cams, scanners, printers etc, digital video requires dependable performance to avoid dropping video frames.

FireWire is a much more independent technology in that it works in a peer-to-peer relationship. For this reason, many professional DV users are now able to download their video from a DV camcorder to an external hard drive without the use of a PC. Finally, and most importantly, FireWire delivers data consistently at a specific rate. If you want to work with video, even to edit the family movie, go with FireWire.

If you are using a laptop, look into a PCMCIA card with FireWire inputs. That's what I use on my laptop for DV with zero dropped frames.

[guns1inger]

The issue isn't bandwidth - as Redwudz said, both are more than adequate. The issue is support. Firewire has been a round somewhat longer than USB2, is, for all practical purposes, faster for sustained transfer, and was adopted as the transfer standard for DV. Unless your camera also supports USB2 transfer of full DV, you don't have any other options.

[terjeber]

On the other hand, USB2 has higher bandwidth than IEEE1394: compare 480Mb per second (USB2) versus 400Mb per second (IEEE1394a).

As another poster explained, this is only theoretically true. Firewire have higher sustained bitrates than USB2 in most situations for the reasons quoted in his post. The issue is what does your camcorder support...

For this reason, I am surprised to learn that there's trouble transferring the native DV data via USB2 in full.

Most of the newer Panasonic camcorders support transfer of DV-AVI to the PC over USB2. I have the GS-400 and it's firewire port is hosed, so I currently use the USB2 port instead. The only software that currently supports DV transfer over USB2 properly on the other hand is Windows Movie Maker, so I currently use that as my capture app. A task it can perform, but I do miss my Vegas capture capabilities, so I will send my camcorder back to get my firewire port fixed.