What is digital video editing? Is it different from nonlinear editing? How do you create digital video for editing? How does DV editing work? What is rendering? What is the difference between DV, Firewire, and iLink? How do I edit using DV from a DV camcorder? Computer-based editing systems versus black box. Which is better? Macintosh versus Windows. Which way to go? Build it myself or buy a pre-configured system? What kind of camcorder do I need? How long should my videos be? The new muvee AutoProducer - the best automatic video editing software What is digital video editing? Is it different from nonlinear editing? Digital editing is simply editing a digital version of video rather than an analog version. Instead of using a tape based analog medium to store the info, you are using digital bits and bytes to store the video and audio. Some call it desktop editing, some call electronic editing, some call it NLE or nonlinear editing. Regardless of what you call it, it is all basically the same. The differences are flexibility and quality. Because you are not actually playing and recording scenes onto a new tape, you can easily and quickly try out different editing patterns. You can try out one series of scenes for your production. If you don’t like it, you can move them around and try out a different series. You can add in new scenes or take out ones that do not work. With an analog tape based system, you would have to start from scratch, re-laying the scenes down on the tape each time you made a change. Digital editing also improves overall image quality. Because you are using a digital format, making changes and copies does not result in generation loss – you are simply copying a digital representation of the video. That is unless you do a lot of signal compression, decompression and re-compression. More on that later. How do you create digital video for editing? It always starts with video captured by a camcorder. If you are using an analog type of camcorder like a VHS or 8m camcorder, your video and audio footage has to be converted into a digital format such as MPEG or MJEG. The video has to be converted from an analog representation (sort of like the groves in a vinyl record) to a series of digital 1s and zeros. There are a bunch of hardware solutions that can do this. These digital capture cards can be inserted in your computer. Prices start at $50 each and go up to the thousands, depending on quality, bandwidth, features and bundled software. If you do not want to open up your computer to install capture card, you can use a MPEG peripheral device such as the Dazzle Digital Video Creator. You plug your analog video (S-video or standard) into the box and then the MPEG digitized video flows over a USB or parallel cable into the computer. By the way, you do not need to playback from tape. You can plug your camcorder or video camera into your computer or MPEG device and capture it directly to the hard drive, eliminating tape. Unfortunately, unless you are using a small portable notebook computer, this limits your videotaping mobility. As part of the hard drive capture process, the digitized video needs to be compressed and made smaller. Raw video streams out at 30 megabytes a second or more. That is a lot of data and most of computers and hard drives cannot handle that flow. By using a variety of compression technologies, the video throughput can be shrunken by a factor of 3 to 1 to 100 to 1. In general, the more you compress your video, the more you reduce your quality. However, compression rations of 3 to 1 and 4 to 1, usually do not create noticeable loss. Compression technologies work by analyzing the video stream and assessing which video information can be left out and eliminated. For example, if you have a person standing in front of a blue wall, the technology recognizes that the blue wall is uniform in color and is not changing, Therefore it can be compressed a lot more than the person who is talking. There are a wide range of different compression technologies including QuickTime, Motion jpeg (M-JPEG), MPEG1, MPEG2 and the new MPEG 4. Confusing the issue is that a technology such as M-JPEG may have various different codecs (short for COmpression-DECompression) that actually do the compression and decompression of the video and audio. Various codecs may not talk to each other. Once the digital video has been compressed and captured onto your computer’s hard drive, editing encompasses two basic functions – database management and rendering. The database management aspect means keeping track of where your various scenes are, how long you want them to be, and then in what order you want them to play back in. For example, when you trim a scene – figuring out where the scene begins and ends, you are not really changing the scene at all. You are simply telling the editing software’s database to keep track of these new video locations and use them when playing back the video. This is why it is easy to change your clip in’s and out’s as well as to create alternate trims of the same clips. When you edit your video together, the database then keeps track of which scene should be played first, which should be played second, and so on. If your entire movie consisted only of cuts, the video would not have to change at all. The database would simply have to keep track of all the in and out points, as well as the playback order of the trimmed scenes. Because it is just a database of play commands – not an actual video file, it is easy to re-arrange the scenes over and over again until you get them just right.
What is Rendering? Depending on your video card, your software and your computer’s hard rive and bus specifications, you may have to render the entire movie before watching it back. In other words, the database is unable to retrieve the scenes fast enough to play back in real time. Therefore, it retrieves them once by one and electronically compiles them together into a new, and longer, file that can be played back all at once. This is how the less expensive systems operate. Effects and transitions also have to be rendered and saved to the hard drive before playback for recording – that is unless you have one of the newer and more expensive “dual-stream” video editing solutions. To create a transition where two or more video streams are mixed together – like in a wipe, dissolve or special effect, the two streams must be uncompressed, electronically taken apart into their ones and zeros, temporarily stored in RAM, mixed back together, and then compressed again, creating a new digital file. This happens frame by frame. This process takes time and lots of computer horsepower. A dual stream solution essentially functions as two separate computers – each handling these series of functions and enables real time or close to real time creation of effects and transitions. Depending on your dual stream system, the commands for these effects can be stored in a database and only implemented upon final playback to tape. Otherwise, the effect can be created in real time and rendered directly to the hard drive, to be later called up upon playback. What is the difference between DV, Firewire, and iLink? Not much. Theoretically, all are based on the IEEE1394 standard for digital video. However, in the real world, various manufacturers have tweaked the spec slightly for their own models. Luckily, these tweaks mostly have to do with power issues and transport controls for the camcorders. By the way, there are new versions of 1394 destined to hit the market soon with much higher throughout capabilities. iLink is a term used by Sony; Apple likes Firewire, and the rest of the industry uses DV or 1394. How do I edit using DV from a DV camcorder? DV is captured onto tape in a digital format. Therefore, unlike analog formats like VHS and 8mm, DV does not need to go through a digitization process to be captured onto the hard drive. In addition, DV is already compressed by using a variety of technologies built into the IEEE1394 standard. Many computers, including most new Apple G4s and Powerbooks, include a Firewire adapter built in. Many new Windows computers are also arriving with built-in Firewire/1394 adapters. There are a variety of 1394 adapter cards on the market that can be installed with your computer. Once again the price ranges, starting at about $50 and going up from there depending on the card's performance, features and bundled software package. Computer-based editing systems versus black box. Which is better? Black Box editors like Applied Magic’s Screenplay and DraCo’s Casablanca are essentially computers in a box with all the required hard drives, software and processing hardware included. Most computer hardware and software solutions are available for both Macintosh and Windows computers. These start at $1500 and go up from there. The advantage of using a black box editing solution is that you do not have to share it with your other computing tasks. There is much less chance of it crashing because you installed a bad program or caught a virus. Black boxes are harder to re-configure and change – this prevents you from screwing things up by experimenting. In addition, black boxes are usually much more portable than desktop video editing systems. About the size and shape of a VCR, all you have to do is hook it up to your TV set or monitor and you are ready to edit. Once your video is digitized onto the black box’s hard drive, you can edit your videos anywhere – in the living room, the garage, or out on the patio. Both DraCo and Screenplay include options for editing DV, as well as bring in graphics, still images and titling. The advantage of a computer-based system is more power and choice of software, effects, graphics and titling. If you already have a powerful computer, doing video editing may only cost a few hundred more for the new boards and software versus $2,000 or so for the entry-level black box products. Macintosh versus Windows? I am not going to touch that on for fear of starting a flame war. Suffice it to say that there are good solutions for both platforms, and personally, I use both. Going out on the limb for the beginner, the new Macintosh G4, iMACs and Powerbooks are very powerful and include a built-in Firewire converter. In addition, Apple’s iMovie software is free and enables the video editing beginner to get a quick and easy start. All you need is your DV camcorder and a Firewire cable (4 pin to six pin). Should I buy a pre-configured system from a video dealer or assemble it myself? This is another loaded question. For beginners, I would recommend assembling a system together. It is quite simple to put together a basic system. By assembling it yourself, you may save money and learn the ins and outs of your system. However, if you are starting a business and want to quickly start generating cash with a minimum of downtime, I recommend using one of the dealers who will assemble, deliver and set you up with a powerful pre-configured digital editing system. I am on several Internet mailing lists consisting of video professionals who use this stuff on a daily basis. Most of them are techies and have assembled their own systems. Despite their wealth of knowledge and expertise, I find that they are always discussing new challenges to the hardware and software set-ups. What kind of camcorder should I use? You can use any type of camcorder as long as it has some kind of video and audio output connection. If you are using a VHS, S-VHS, 8mm or Hi8mm camcorder with analog outputs, you need a computer editing system that can accept analog video and audio and has the matching connectors. Most editing systems, especially the less expensive consumer and prosumer cards, use standard RCA plugs. Most analog cards also include a S-video connector for connecting to s-video camcorders. However, these are still analog recording units. The process of capturing and playing back and analog signal from tape results in a 10 to 20 per cent loss in resolution and quality. I recommend using a DV camcorder. The prices are dropping quickly. By using a DV camcorder, you have the choice of using either an analog or a DV card in your computer. For example, if you already have a M-JPEG capture card, you can input high quality video from the camcorder’s analog outputs. DV camcorders excel by enabling you to record the video in a digital format on the tape. When played back through the DV Firewire connector or via the analog connectors, the video still looks great. For example, my Apple G4 has a Firewire jack. My Pentium computer has a Matrox MJPEG and a Vitec MPEG capture card inside. Both of those cards use standard RCA and S-video analog connectors. When I want to digitize video I have a choice. Moreover, to tell the truth, I cannot see much difference between the raw video played from the DV connector versus the S-video analog connector even thought there is an additional decompression step required for the s-video playback. They should be as long as they need to be. Some of the first editing systems required actually digitizing and rendering the entire movie prior to playback. Sometimes this forced you to come up against the Windows 2 gig limit for continuous files. Most of today’s data-based programs simply play back a series of shorter files one after another, to avoid that problem. However, despite that, the shorter and more concise your movie, the better your audience will appreciate it. When I went to film school, my teachers taught me a rule of scene length. You see the scene, you see what happening, now move on to the next scene.
Check out Doug Dixon's Digital Video Editing Software Gallery
Software applications for digital video editing (and some with DVD authoring), organized from consumer to professional. Each application includes a brief description, and information on the latest released version. Product descriptions and images are summarized from published information.
WEB INFORMATION: Apple Computers www.apple.com Applied Magic Sequel and Screenplay Black boxes www.applied-magic.com Canon Camcorders www.canon.com Digital Origin editing systems for Mac and Windows www.digitalorigin.com DraCo Systems Avio and Casablanca Black Boxes www.draco.com Dazzle MPEG Devices www.dazzle.com Matrox Digital Editing boards www.matrox.com Sony Computers & Camcorders www.sel.sony.com | 
