high-definition and firewire, usb

I am transfering hd video files from the computer to an western digital hard-drive using my usb cable, because I still can´t mount my firewire drive. Am I losing video quality doing this? Will it be the same with the firewire?
Thank you for your help.


macbook Mac OS X (10.4.9)

Posted on May 8, 2007 10:27 PM

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10 replies

May 9, 2007 6:36 AM in response to should of

While 'on paper' the maximum speed of USB 2.0 high speed is faster than firewire 400 (480MBps vs 400MBps), anyone who has compared the two with appropriately similar hardware knows that firewire is actually more efficient.

It has to do with the amount of logic overhead in the protocol. USB has a lot of logic going on that takes up part of that bandwidth (I'm not sure if it has to do with the amount of devices it has to be prepared for, or just non-efficient protocol practices).

The firewire protocol is very streamlined for sending large amounts of data back and forth. So when you have a choice between the two for large bandwidth transfers, firewire is always a safer choice.

May 9, 2007 7:19 AM in response to Fortuny

Well, there is a potential issue with that as well. You want to avoid streaming audio/video to the system drive whenever possible as due to OS, Applications, and caching that drive is doing a lot of stuff that could supersede the video stream.

You can use internal drives, but since we are talking in a Macbook forum you can't have a non-system internal drive unless your booting externally, which would be a bit odd. As such your best bet would be an external drive for that, as long as there is enough bandwidth, so raw HD streams would definitely be out, but MPEG2/4 streams would be fine, as well as HDV IIR.

May 14, 2007 6:49 AM in response to should of

Losing frames would be losing quality. You would have dropouts in your video stream.

Although since we are not talking about raw video, more likely HDV or MPEG Streams, there are not discreet frames for every frame in the original captured video, rather full frames every so often, then a number of frames that are made up of the differences from frames before/after it. In this case as you lose bits you can see some general degradation of the video stream rather than just a single lost frame or parts of a single frame.

If there is a hole in a frame, and the next 5 frames reference back to it just as changes, that hole will be carried through for those 5 frames.

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high-definition and firewire, usb

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