capture via USB 2.0 or Firewire in AVI type 1 or 2.

[philebus]

Hi,

I have searched the forums and realise these issues have been covered in different contexts, but the answers have not, to my mind, been definitive. I really have 3 questions.

The first, relatest to capturing video from my panasonic nv-gs250 to my computer via the supplied USB 2.0 cable, and panasonic software Motion DV Studio. I have already tried this and it works quite well. The video is captured in DV AVI type 2 format , 24 bits 720 x 576. I then edit the captured video with Ulead Videostudio 9 and output to file still in AVI 2 format. My question here is straighforward is capturing via USB 2.0 from camera to computer going to yield the same quality as capturing via firewire cable (which my computer is not yet set up for). Let's assume that for both I am capturing AVI type 2.

My second question concerns whether there is any quality differentials between DV AVI type 1 and AVI type 2. I know lots of people say it is easier to edit AVI type 2 and that it has many advantages over type 1, but I am interested in maintaining the highest quality, and it seems to my untrained mind that if AVI 1 is exactly the way the video is on the tape, and if it captured in this form to the computer, then it would yield better results in the editing phase, assuming the editing program can handle avi type 1 files.

If there is absolutely no quality difference between AVI type 1 and 2, then I see no reason to go out and buy and install a firewire kit, because my current set up is working well. If AVI 1 does have the advantages I feel it might have then I will have to go down the firewire route, and change my current practice, and capture with VS9 directly. That is, unless I can convert my AVI 2 files to type 1 and regain the original form of the file on the tape in the camcorder.

So my third question is, if I do convert AVI 2 to AVI 1 using a program like DV Date, will it take me back to the original uncompressed and unaltered form of the AVI on the tape in the camcorder, or is something lost in going from tape to AVI 2 and then back again to AVI 1?

Sorry for the long and multiple questions. Hopefully somebody has some informed views on all or some of these matters.

[piano632]

There is no difference in quality between DV type 1 and 2. The only difference is with the audio track. Type 1 has the audio interleaved with the video track (best for keeping audio in sync). Type 2 has the audio on a separate track (best for editing). But both are identical in quality. You can convert back and forth between the two types without any quality loss.

[philebus]

Thanks Piano 632.

The reason I thought there might be a difference in quality between AVI 1 and 2 is that the file properties tab in Videostudio 9 lists my the video captured from the panasonic camcorder as follows:

compression - Panasonic DV CODEC -- type 2
attributes - 24 bits 720 x 576

It is the compression information that led me to believe that the file might be of diminished quality. So are you saying the Panasonic DV AVI 2 codec does not reduce quality at all vis a vis AVI 1? That it is, in other words, totally 'lossless' I guess you are, but I just want to be sure!

thanks

[Safesurfer]

Read this -

https://www.videohelp.com/glossary?D#DV


and this -


http://www.dvcollections.com/support_dvcompress.html

[redwudz]

Firewire is considered to be the standard for transferring DV video to and from a DV camcorder. Some people have quality issues transferring DV through a USB port.

USB 2.0 is fast enough, but can lose the DV stream when another USB device wants it's share of the USB channel. Some cameras only transfer low quality 'web' video using USB. I would purchase a Firewire card myself. That's what's most camera manufactures will recommend.

Type 1 or Type 2 use depends mostly on what program you are putting the DV into, editor or encoder. TMPGEnc encoder doesn't seem to work with type 1. Type 2 is fine. As mentioned, it's just two different methods of interleaving the audio and the video.

And DV video is far from uncompressed, it's about 5:1 compression. But MPEG and Divx are much higher.

[terjeber]

As you have noticed, the Panasonic allows for full DV quality transfer over the USB-2 port. Generally this transfer will work splendidly, and you will not lose any quality at all. As others have noted, you should make sure no other USB devices are in use when you capture, they most likely will interfere with your transfer and you will lose frames.

The only two apps I know that will currently capture DV across USB-2 is the included Panasonic app and Windows Movie Maker. If you chose to upgrade later to a better editing app like Sony Vegas or similar, that means you can not capture using the advanced capture applications these usually have.

For that reason, and so that you can avoid problems with USB capture going forward, I would recommend going with FireWire. Sadly the FireWire port on my GS-400 is hosed, so I am stuck with USB-2 for now, but it is enough of a hazzle that I will ship my camcorder back to Panasonic to have it fixed, even if I have to pay for the fix.