if you know about firewire and video capture.. please help me.

[smp]

I have a freind, she just baught a brand new computer with firewire. She only just approached me with the problem, and I don't know anything about firewire, but I thought I could ask my fellow TA's.. so yeah. As far as I can tell, she has a PIII system on a cusl mobo.. She told me she baught firewire and has a DV.. she has a matrox video card (doesn't know which one).. she says that her captures are jerky, and she doesn't know what kind of a hdd she has. I would right away assume that it's the hard drive.. cause you need speed for video capture. So what exactly happens when you capture video? It is coming in at real time, lot's of megs a second need to be copied to the hard drive. So what components do you need to have to do this well? I would think ram, for buffering, and like a raid or raid scsi? Is it possible to use firewire with a standard 7200 rpm hhd and get smooth captures? I have no experience with firewire? Firewire is just a card right? you plug it into a pci slot and you get the firewire cable, and your off yeah? Someone please give me the low down on this.. and remmeber, I'm a complete lamer newbie on this one. thanks.

 

[smp]

oh! And what relationship is there between a video card and a firewire card? any?

 

[road]

Ok SMP, you have alot of questions there buddy. Now the whole deal with Firewire is, FireWire (IEEE 1394) is one of the fastest peripheral standards ever developed. FireWire is a key technology for digital video professionals, and FireWire devices can be daisy-chained together to link as many as 63 devices simultaneously. The new Firewire cards come with a 400Mbps FireWire port, so you can connect to and transfer files back and forth at phenomenal data rates. Plus it?s hot-pluggable, so you don?t have to turn off or restart your Computer when you attach or remove a peripheral. With video editing, you need a fast hard drive and eventhough your firewire port can burst much more data than you HDD bus, the video capture will only be as fast as the transfer speeds on your HDD. Also your firewire card has usually nothing to do with your video card, but in this case it might depending on what kind of video capture technology you are using. Sometimes software captures video for you other times the video card does it for you. If you have your Video camera plugged into your firewire port, forget about the video card as it had nothing to do with it. If your camera plugs into your video card and you have a firewire HDD, then yes your firewire is kinda dependent on your video card. With either of the setups video capture should be pretty smooth. If she has a 5400rpm drive, it may be the cause of the problem, try it with a faster drive, ti'll be much smoother. RAID and SCSI will definitely help the cause of speed, so yeah those will help.

Hope this helped.

Peace..

 

[Urdumb]

DV only requires 3.6MB/s so it's unlikely that it's the hard drive unless she has DMA turned off - even then it's unlikely. Any old 5400rpm drive does the job fine - if it didn't then how the heck do laptops do it with their 4400rpm drives eh?

When you say the captures are jerky what do you mean? On playback they are jerky? That's normal at full size - I playback my DV footage at 18-19fps.

 

[Pariah]

First off, you video has nothing to do with DV, and has no affect on it. A Urdumb stated, DV is only 3.6MB/s which practically any drive you can find can do, so it is very unlikely it is the HD. Some editing software will give you the option to recover lost frames. This is possible due to the digital nature of DV which stores movies with timecoded frames. If a frame is skipped, the software will automatically rewind the DV camcorder and recover the frame. If you have this option then the storage medium you are using is completely irrelevant to the point you could use a floppy disc if it had enough storage space.

The captures your friend has are not choppy they just appear to be because the computer she is using is most likely not fast enough to play them smoothly. If she were to send the footage back to her camcorder it would play smoothly if run through her TV.

 

[smp]

really? I think that she just got the pooter in the past month.. I'm sure it's at least a 700, but I would think more.. what speed would you need to play it back smooth? She can play dvd's smooth she said..

 

[Urdumb]

A 900mhz chip should get pretty close to full decode speed. Some of it depends on the DV codec that's being used. In my case it's the Canopus codec on a 566mhz.

 

[Pariah]

The speed of playback is highly dependent on the codec. 700 won't be enough for full speed full size playback with some codecs.

 

[MadRat]

Ask her how much memory she has in the machine. You'll also want to tell her to avoid Celerons with their 66fsb for DV capture. We use a lowly P!!!-550 at work. The key is that its a 100fsb cpu, 256mb RAM, and a 7200rpm hard drive. It too has a lowly Matrox video card, but it doesn't tax the videocard at all. The cpu, hard drive speed, and memory have alot to do with the efficiency of your DV playback.

 

[AtmosFear]

The problem is that digital video editing cannot be done on a PC.. It requires a Macintosh, which has firewire built in. Tell your friend to ditch the P3 and get a Mac instead.

AC

 

[MadRat]

We know thats b.s.