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The World’s Top Tips for

Pinnacle Studio Video Editing software

(with some Avid Liquid snippets)












A DIGITAL VIDEO PRIMER

This excellent article was produced by Peter Allwood, and is reprinted here from his own site.

 

 

Digital video can be categorized by two major differences from its analog predecessors:

  • A high resolution for sharper images
  • No loss of quality regardless of the number of copies made

 

Still uses Magnetic Media

Digital video is still recorded onto magnetic tape via the camcorder.  However, rather than being recorded as analog signals, the video frame is digitized into 0's and 1's and written to magnetic tape similar to how a computer might records its data onto a floppy disk.  The information written includes error correction codes, so that even if some data is missing on playback, it can be reconstructed using these error correction codes so no information is lost.  All digital camcorders include timecode as a standard feature.

Digital Camcorders becoming more affordable

Digital camcorders have been very expensive, but over the last year they have dropped significantly in price such that they are now cost comparable to the high-end Hi8 camcorders.

Sony has helped this competitive environment along with the release earlier in 1999 of their line of Digital8 camcorders.  These camcorders are digital, but record their data to standard MP or ME Hi8 tapes.  They can also playback Hi8 and 8mm video formats.  Consequently, they provide a convenient and fairly cost-effective migration path from Hi8 to digital, and allow you to reuse your existing inventory of video tapes.

Smaller capacity tapes

Because a lot more information is stored on tape with digital video than with analog recorders, tape capacities tend to be shorter.  For example, with a Sony Digital8 camcorder, only one hour of video can be stored on a 120 minute Hi8 tape.  The Mini DV cartridges used by standard digital camcorders are also typically of 60 minute capacities.

One interesting side effect of the Digital8 system is although record/playback speed on Digital8 is still 30 frames per second, the tape must travel at twice the speed than it did in a Hi8 device.  However, the physical tape rewind and fast forward speeds remain the same as they were with the Hi8 camcorders.  Therefore, it takes twice as long to fast forward or rewind to a given position on the tape (as represented by hh:mm:ss:frame) as it did with a Hi8 camcorder.

IEEE-1394 Interface (Firewire):

All digital camcorders have an IEEE-1394 interface, which is also commonly called the Firewire interface.  This is a high-speed data transfer interface capable of sustaining data rates of up to 500 megabits per second.

The interface is bi-directional.  Video stored on a camcorder's magnetic tape can be read by another device (i.e. a PC or another digital camcorder or VCR) and may also be written to (i.e recorded) via the IEEE-1394 interface.

(Note.  In some instances, the record (DV-IN) function is disabled on European versions due to VCR import restrictions.  Check with the camcorder manufacturer to ensure that your IEEE-1394 DV interface is bi-directional, otherwise digital editing using your camcorder will not be possible)

There are two types of IEEE-1394 interface adapters, 4 pin and 6 pin.  The only difference is the 6 pin adapter provides a power source for an external device and the 4 pin adapter does not.  As camcorders have their own power source, they mostly have 4 pin adapters, whereas PCs with built-in or with add-on IEEE-1394 ports tend to have one or all 6 pin adapters.  My Sony VAIO has one of each.  Pinnacle's new StudioDV PCI card provides two external (and 1 internal) 6 pin port.

There are four to six pin adapter cables readily available to allow digital camcorders to plug into a 6 pin PC based port.

One thing I did experience with IEEE-1394 cables was sticker shock.  The price of a 4 pin to 4 pin, 6 foot long cable at Best Buy was $79 US.   StudioDV comes with a cable, my Sony VAIO did not.  Might be something you want to hunt around for a good price on early in the buying process, so you are not running down to the local discounts store at the last moment to get the "missing link" (needless to say I paid the $79 plus tax, but I was able to start playing the same night - a small price to pay).

Some important things to keep in mind

  • Digital Video consumes 240 megabytes per minute or 13 gigabytes per hour of disk storage
  • A constant data rate of 4 megabytes per second to and from the hard drive is required when capturing or  recording digital video via the IEEE-1394 port
  • Only disk devices that can provide a constant uncached data rate of 4 megabytes or better can be used.  Caching performance is unimportant as the data volumes involved with flood any cache in a fraction of a second.  Uncached performance is what matters.
  • UDMA-66 and 7200 RPM IDE disk devices will meet the audio/video requirements provided they are not on an IDE channel with a slower device (such as a CD-ROM).
  • Most SCSI Fast, Fast & Wide and SCSI Ultra will meet the required data rates (7200 RPM devices required).
  • Most problems encountered will be associated with trying to use disk devices and PC's that cannot sustain the required data rates, or are misconfigured.   Symptoms will include missing frames, erroneously terminated capture or records, tool errors and hung systems.
  • To edit a one hour video from two hours of source material using a typical NLE toolkit (Adobe Premier or similar) you need a minimum of 3 hours worth of disk space, or 39 gigabytes
  • Digital video is captured, stored and manipulated on the PC as AVI files.
  • The maximum size of an AVI file is 2 gigabytes (4 gigabytes with Windows 98 and FAT-32), or approximately 8 - 9 minutes of video
  • Video clips that exceed 8-9 minutes in length are split into multiple AVIs
  • Rendering is the process of making an output AVI from the specified series of input clips, transitions and titles.  It is a very time consuming process.
  • With a single audio/video drive, rendering will take, at a minimum, twice as long as the length of the video being created (much longer if transitions and titles must be generated), as the video must be read from the source AVI and then written to the target AVI, both of which reside on the same disk device.
  • Typical PC functions, such as file copy's, become unwieldy when dealing with files of these large sizes.  Just copying a small (2 minute video) to another file takes 4 minutes.  Running disk defrag on a highly fragmented 25 gigabyte disk is a lifetime experience (or seems like it)

 

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