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Chapter 2: Windows XP and Digital Video: The Perfect Partnership
- Tools Inside Windows XP for Digital Video
- Thumbnail Folder View
- Detail View
- Task Pane Information
- File Properties
- Windows Media Player
- Windows Movie Maker
- Third-Party Digital Video Tools
- Digital Video Compression Explained
- Why Is Digital Video Compressed?
- Bit Rate Explained
- Psychoacoustic Audio Compression
- Psychovisual Video Compression
- Lossless Compression
- Lossy Compression
- Terminology You Need to Know
- Codec
- Digital Artifacts
- FireWire
- USB 1.1 and 2.0
- Digital Audio File Types
- Digital Video File Types
- Digital Image File Types
- Key Points
Chapter 2 Windows XP and Digital Video: The Perfect Partnership
Microsoft Windows 95 and Windows 98 brought a new level of multimedia power to the Windows platform, and Windows NT and Windows 2000 were rock-solid platforms for business computing. It wasn't until the arrival of Windows XP that we were given the combination of stability and multimedia flexibility. And, not coincidentally, it's the first operating system that my mother can use to check her e-mail—it's far less intimidating than previous efforts from Microsoft. And that's a good thing! If you're using Windows 95, Windows 98, or Windows Millennium Edition, do yourself a favor and upgrade to Windows XP. There's nothing worse than working on a video editing project for hours and then having the application or entire operating system crash, potentially losing your work. Windows 2000 and Windows XP share the same stable code, but Windows XP adds more multimedia flavor to the mix.
Tools Inside Windows XP for Digital Video
Right out of the box, Windows XP Home and Windows XP Professional come with some great features for the multimedia-hungry among us. These features are so well integrated, in fact, that most people overlook them entirely. The first category of tools involves the way your video files are displayed inside folders, and the second category deals with digital video applications included with Windows XP.
Thumbnail Folder View
Most people figure out the Thumbnail Preview mode (in any folder, click the View menu, then Thumbnails) in their My Pictures directory pretty quickly, but did you also know the Thumbnail mode works for most video files as well? It's easy not to realize this because it can take several seconds for your computer to decode the video files and give you a preview; so if you're on a slower computer it may look like nothing is happening. If the video file starts by displaying a solid color (many do), your thumbnail preview will be an uninspiring black icon. Figure 2-1 shows a video folder that I have, and the icons are all the first frame of my video. This makes it easy to browse through a folder and pick out the right video because in most cases you'll recognize the video by looking at the first frame. I use the Thumbnail view most of the time because I'm a visual learner and I find it easy to look at a folder and quickly see what files are in it.
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Figure 2-1 The Thumbnail view is displayed.
Detail View
The Detail view, illustrated in Figure 2-2, has unique features when selected in a folder containing video files. In addition to the standard columns like Name, Size, Type, and Date Modified, there are columns for the duration of the video (measured in hours, minutes, and seconds) and the dimensions of the video. This can be quite useful if you're looking at a large folder of video files and you need to find short clips to use as transitions in your video or combine clips based on their resolution. The Type is also useful to sort by—if it simply says "Video Clip," it's a video file in AVI format (explained later in this chapter). MPEG files are denoted as such, as are Windows Media Video (WMV) and Windows Media Audio (WMA) files. Unsupported video formats, like QuickTime, do not have duration or resolution information displayed.
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Figure 2-2 The Detail view is displayed.
Task Pane Information
Task panes like the one seen in Figure 2-3 give context-sensitive shortcuts based on what options the user has with that sort of data.
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Figure 2-3 Task panes are an important part of Windows XP.
When you click a video file, you have the following task pane options:
- Play All This option starts up the Windows Media Player, puts every video file that's inside that folder on a playlist, and begins to play them all based on the order in which they were sorted in the folder (name, size, length, etc.) You might use a function like this if you had prepared several videos and, before burning them to CD or DVD, you wanted one last viewing.
- Copy To CD This function will copy the files to a temporary folder, and if you don't have a blank disc in your CD-R drive, Windows XP will give you a notification message that there are files waiting to be written to a CD (if you have a CD in the drive, it will start up the wizard for CD burning). From the file window that appears, you can burn them to a CD, add more files, or delete those temporary files without affecting your original files. Remember that a blank CD can store between 650 and 700 MB of data, so in many cases it won't be big enough for raw video footage. After you've finished your product, it just might fit—we'll talk about this in Chapter 10.
- Rename This File Functionally the same as hitting F2, this allows you to rename your file. If your files have less-than-descriptive names, consider renaming them to add shooting date information, location, etc.
- Move This File A quick way to move a file or files to a new directory or drive. I tend to use Control+X (Cut) and Control+V (paste) to move files around.
- Copy This File This function will make a copy of the file in whatever folder you specify in the window that pops up.
- Publish This File To The Web This command will start up the Web Publishing Wizard. This easy-to-use wizard will step you through creating a Web folder and uploading your video to that folder. There's a 1 MB limit per file, however, and a 3 MB overall size limit (unless you upgrade from the free service), so this service isn't for larger video projects.
- E-Mail This File Click this task to open up a new message from your default e-mail client and attach the video file to it. We'll discuss issues of e-mailing video files to others in Chapter 9.
- Delete This File Pretty self-explanatory. The file is deleted and sent to your Recycling Bin, unless the video file is larger than your Recycling Bin can accept, in which case it will ask you if you want to permanently delete the file. Be careful—if you say yes, it's impossible to recover that file without a third-party tool, and even then it may be damaged if data is written over the spot on the hard drive where it used to be.
- Details Pane This area contains a lot of useful information. If you're in any other View mode than Thumbnails, you'll see a small version of your video. It will only show the first frame, not your video (this feature existed in Windows 2000, but was removed in Windows XP). You'll also see much of the same information you'd get in the Detail view—video file type, date last modified, file size—and it adds author information if that is embedded in the metadata of the file.
The task pane is very useful, but I hope that someday third-party companies and end users will be able to add to the list of Video Tasks at the top. It would be useful to have commands for Edit Video, Convert Video, etc., in the Video task pane.
File Properties
If the information provided in the Details view isn't enough for your needs, right-click the video file you want to investigate and select Properties. The General tab tells us very little, but the Summary tab shown in Figure 2-4—now there's the good stuff! The unique information here includes the bit rate (explained below in the terminology section), the audio sample size, the format of the audio, the frame rate of the video, the data rate of the video, the video sample size, and the video compression. Some of this information is useful to us, some of it isn't. You'll learn what most of these terms mean below, but the lesson to take away here is that when you need to know the details about your video file, checking out the properties is the best way to find them.
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Figure 2-4 The Properties Summary tab tells you a lot about your video file.
Windows Media Video (WMV) formatted files have two fields that Windows XP can access and update that other video formats do not: Title and Comments. If you have a WMV file, view the properties by right-clicking the file, left-clicking Properties, then selecting the Summary tab. You'll see both Title and Comments fields as Figure 2-5 shows, and more than likely they'll be blank (I've entered some information about the tool I used and the date the images were shot). To enter your own information, simply left-click the blank space and you'll get a blinking cursor. Start typing! You can enter whatever sort of information you want, but be aware that it's just for your own reference—as far as I've been able to determine, this information doesn't show up in Windows Media Player when playing the video nor can any tool on the market index or search it. It's basically just for your reference.
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Figure 2-5 You can update Title and Comments fields with useful information.
Windows Media Player
Recently released in beta at the time of this writing, the 9 Series Windows Media Player shown in Figure 2-6 is a significant upgrade to the Windows Media Player that came with Windows XP. It offers enhanced playback features, support for third-party plug-ins, variable bit-rate audio encoding (this gives you greater sound quality with smaller file sizes), and a host of other improvements. The Media Library functionality has also been greatly improved, so it's easier to work with your media and build playlists. Unfortunately, many of the same issues still exist from the last player—playing the video and audio clips in the Media Guide cause a confusing series of Web browsers to pop up instead of playing the content inside the player. And even with the improvements in how video is streamed, every video clip I tried to watch after installing the beta software sputtered and paused continuously—this is no fault of the player, however. Movie studios and Web sites with multimedia content aren't providing adequate bandwidth for their visitors.
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Figure 2-6 This figure shows the 9 Series Windows Media Player.
Windows Movie Maker
Windows Movie Maker, shown in Figure 2-7, is a tool we'll discuss in Chapter 7 when we delve into the basics of video editing. As a video-editing tool, it looks very basic, lacking even a single transition (an effect that allows you to move from one clip to another—like fading to black, etc.), but it's a perfect place for beginners to start and has some surprisingly useful features. It allows you to record video and audio signals from a variety of sources, offers scene detection (where it splits up video clips based on scenes), and has a variety of preset output templates. I have to admit, I wasn't very impressed when I first fired it up, but for simple projects where quality isn't paramount (e-mail and Web sharing), it's quite a useful little application. And did I mention it was free with every copy of Windows XP?
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Figure 2-7 Windows Movie Maker is perfect for simple projects.
Third-Party Digital Video Tools
Although technically not a "part" of Windows XP, the compatibility that Windows XP has with video tools created by third parties is impressive. Unlike the Macintosh or Linux platforms, a huge number of companies are creating digital video hardware and software solutions. Pinnacle, Ulead, muvee Technologies, Adobe, ADS, Maxtor, Western Digital, Sony, Adaptec, Sonic, Panasonic, Canon, Roxio, Sonic Desktop—these are just a handful of the many companies offering products for the digital video market. The sheer variety of choices that you have with Windows XP is refreshing—I wouldn't want to be limited to only a couple of choices, and neither would you. We'll discuss third-party video tools throughout the rest of the book, but for consumer-level video editing, Windows XP is my platform of choice. Don't believe people who say, "You need a Mac to do digital video." Hand them a copy of this book and they'll learn the truth.
Digital Video Compression Explained
You'll see the term "compression" used throughout this book, so I thought it was important to explain what it is and why it's important. The term "compression" simply means "to make smaller." The most common form of digital compression that you're likely familiar with are the ubiquitous Zip files—Zip files are everywhere, and Windows XP has built-in support for opening them (but not creating them—you need WinZip from www.winzip.com for that). The easiest way to understand compression is to think of an object like a hamburger (work with me here). A hamburger is usually composed of different kinds of food, like lettuce, tomatoes, beef, and a bun. Most of us make homemade hamburgers that are bigger than our mouths can fit, so it's common to see someone squish the burger down before taking a bite—one could say the burger goes through premastication compression. With me so far? The materials become smaller in different ways—the bun has a lot of air in it, so it gets smaller very easily. The beef, on the other hand, would only compress a little bit because it's already condensed into a hamburger patty. You end up with a smaller hamburger overall, but some of the elements compress more than others.Now, believe it or not, the same logic applies to compression on your computer. Things like text files are full of "spaces" that can be compressed very tightly—a text file can be made at least 90 percent smaller, resulting in a great compression ratio (the ratio of compressed data to uncompressed data). Other file types, like MPEG video or JPEG photos, hardly compress at all—that's because they're in a file format that's already compressed. Why is this important to understand? Keep reading.
Why Is Digital Video Compressed?
As odd as this sounds, one reason digital video is compressed is that our senses don't know any better. Researchers have charted the limits of the human sensory systems over the years, and we know that humans can hear sounds ranging from 20 hertz (Hz) to 20,000 Hz. We also know that although mathematically there are billions upon billions of colors, as humans we can perceive roughly 1024 shades of the same color. That's a huge range of possible colors, but if every one of those colors takes up space in a digital file, does it make sense to have them all in a picture if we can't tell the subtle difference between one color and the next? There's also the matter of redundant images—if, in every second of a 60-second video, there's a chair in the same spot, why save the data of that chair in every frame of the video?Another reason compression exists is to cut back on the amount of space needed to store digital video. How big would digital video be if it weren't compressed in some way? It would take up a staggering amount of room! I found this interesting formula on www.adobe.com:
Frame size K = ([Pixel Width x Pixel Height x Bit Depth] / 8) / 1024
Frame size K = ([720 x 480 x 24] / 8) / 1024 = 1012.5 KB
That tells us that one frame of raw, uncompressed video footage at standard digital video (DV) resolution (720 x 480) would take up roughly 1 MB. And since video is usually around 30 frames per second, we're looking at 30 megabytes per second (MBps) of video! A short, five-minute video would require 9000 MB, or 9 gigabytes (GB), of storage. And if you were shooting a 60-minute video? That's 108 GB—and remember, that's just for the video. It gets even bigger when you add audio. In addition to the tremendous storage you'd need to work with uncompressed video, there's the issue of having a computer fast enough to handle it. Throwing around a digital signal at a sustained rate of 30 MBps is almost impossible for most computers to keep up with—the FireWire hard drive from Maxtor that I tested could only write around 9.1 MB per second. That's quite fast for an external hard drive, but not fast enough to work with uncompressed video. In order to make video easier to work with, we compress it.
By throwing away the data that we can't perceive, we get compressed video. Standard DV cameras compress video at a ratio of 5 to 1, which allows them to store more information per tape. Different video formats offer various options for compression—some allow you to compress the video up to 100 times smaller than the original. Too much compression, however, can be a bad thing. Remember that the more you compress a video, the more data you're throwing away. Throw away a lot of data, and the changes become noticeable. Throw away even more data by using heavy compression, and you'll get a video that you can hardly recognize!
Bit Rate Explained
I was talking about how much data uncompressed video would take and referring to it in terms of MBps. Bit rate is the common term used to describe how much data exists, per second, in a given stream of data. You might have seen audio files referred to as "128-Kbps MP3" or "64-Kbps WMA." Kbps stands for "kilobits per second," and the higher the number preceding Kbps, the higher the amount of the data. The 128-Kbps MP3 audio file contains twice the data of the 64-Kbps WMA file and would be twice the file size. However, some file formats can use their data more effectively than others, so the 64-Kbps WMA file would sound just as good as the 128-Kbps MP3 file. It's a little confusing, but I'll explain how this works in the next section. The important thing to understand here is that the higher the bit rate, the more information there is, and thus the more effort it takes to decode that information. Selecting the proper bit rate for your projects depends on the playback target: if you're making a VCD for playback on a DVD player, the video needs to be exactly 1150 Kbps and the audio 224 Kbps. A typical Pocket PC running at 206 megahertz (MHz) can work with MPEG video up to 400 Kbps—anything above that will cause it to sputter during playback. Later in the book, when I get into the details of creating appropriate output formats, this will make more sense.
Psychoacoustic Audio Compression
Psychoacoustic looks like a complicated word, but it simply means "the way your sense of hearing and brain interpret the sounds you hear." I mentioned above that a 64-Kbps WMA file would sound just as good as a 128-Kbps MP3 file. But if the MP3 file has twice as much data per second as the WMA file, how can it possibly sound better, you ask? Simple: The WMA format packs more of the good sound and gets rid of the stuff that you can't hear anyway. The digital audio on a music CD is compressed to 1411 Kbps, and few would argue with the quality of a CD. MP3, WMA, and any other form of compressed audio are based on powerful mathematical algorithms that discard audio information that we can't hear. Here's an example: If I shout at the top of my lungs and also lightly tap my foot, you'll hear my voice above everything else. Will you hear my foot tapping? Likely not. Yet in the strictest sense, that foot-tapping noise is still present, and in a digital world that would represent data. By getting rid of that foot tapping, we'd end up with less information and therefore a smaller file size. The MP3 psychoacoustic model was created way back in 1987, so when Microsoft introduced the WMA model in the late 1990s, it simply had a better model that was able to produce better-sounding audio in less space.
Psychovisual Video Compression
This term is very similar to its audio counterpart, so I won't repeat the same explanation. Instead of discarding audio that we can't hear, however, psychovisual models discard things that we can't see. For instance, an uncompressed video shot of a wall that is painted black would have a black pixel for every spot on that wall. But if it's just black pixels over and over, why not store one pixel that simply replicates itself to fill up the space? This type of compression is called "statistical data redundancy," which simply means to discard data that's repeated. This, and other mathematical tricks, allows video formats like WMV and MPEG to be highly compressed while still retaining good quality.
Lossless Compression
The term lossless means "no loss of data." When a file is compressed in a lossless fashion, it means that 100 percent of the data is still there. If you zip a Microsoft Word document, it will get smaller, but all the letters of your document are still present when you unzip it. You can also save lossless video over and over without any loss of data—any compression applied simply squeezes that data into a smaller format and does so in the same way every time. In the video world, lossless compression would be achieved by using an AVI file. Lossless compression typically results in only minor compression (3:1) because you can compress only so much data without discarding it. Other forms of lossless data include WAV and bitmap (BMP) files.
Lossy Compression
Lossy compression formats include WMV, WMA, MP3, MPEG, and any other form of compression that discards data in order to achieve a lower bit rate (this includes image formats like JPEG). Using the psychoacoustic and psychovisual rules described above, you'll end up with a much smaller file size but less of the original source data. And although this would seem to defy logic, every time you save your file in a lossy file format, it discards more of the data—even if you're saving it in the same format. A good rule of thumb is to move to a lossy format only as the very final step in your project. We'll talk more about this in Chapter 7 when we delve into editing your video.
Terminology You Need to Know
Unless you're the kind of person who curls up in bed with a dictionary instead of a good book like this one, the word "terminology" probably makes you yawn. I won't bore you with detailed histories of each term, but understanding what words mean is important to getting you on the digital video fast track.
Codec
A codec (short for compressor/decompressor) is a type of translator for video and audio data. If that translator (codec) isn't present on the computer trying to play the audio or video file, it won't play back properly, if at all. Have you ever downloaded a video file and, when trying to play it back, you get audio but no video? That usually means you're missing the right video codec, but you have the correct codec for audio. Conversely, if you get video but no audio, you might be missing an audio codec (this is much rarer than a missing video codec). One of the problems with sharing video online today is with users creating videos using codecs that not everyone has. It's important to encode your video using codecs that your users will have. If you do want to use a special codec, make sure you indicate which codec is needed to view the video and where people can get it. I've noticed that codec problems are more frequent with AVI files—it's rare to get an MPEG or WMV file that won't play.
Digital Artifacts
Have you ever looked at a JPEG photo that's "blocky"? Parts of the images look pixilated and very "digital." Or have you looked at a video file and seen squares making up the edge of someone's face instead of a smooth line? Those are all examples of something called digital artifacting. When an image or video is highly compressed, the loss of data becomes noticeable to the viewer, usually in the form of visible areas of discoloration or the partial destruction of a shape (like a smooth line). In Figure 2-8 I took a high-quality JPEG image directly from my digital camera (a Canon Powershot S110) and applied a 90 percent JPEG compression to it. The original image is on the left, and no digital artifacts are visible. The ultra-compressed image is on the right, and although the file size of this image would be much smaller than that of the image on the right, you can see many examples of digital artifacting. The color on the wall isn't uniform, her jacket looks blotchy, and the overall quality of the image is poor. I overdid the compression on this image to make the effect obvious, and thankfully it's unlikely you'll ever see an image quite this badly compressed on the Internet. You will, however, run across video like this; because video files are so large and bandwidth is so expensive for people with Web sites, they'll overcompress the video past the point of good quality.
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Figure 2-8 On the left, a standard JPEG image with minimal compression. On the right, a highly compressed image showing extreme digital artifacting.
FireWire
Also known as IEEE (Institute of Electrical and Electronics Engineers) 1394 and iLink (the Sony name for it), FireWire was invented in 1995 and although largely a Mac-based technology for several years, the digital video industry has accepted it as the de facto standard for connecting DV cams to computers. To keep things simple, I'll be using the term FireWire throughout the book, but if you hear someone refer to iLink or IEEE 1394, you'll know it's the same thing. FireWire goes far beyond video cameras, including a host of external devices from Web cams to hard drives. FireWire offers blistering performance—up to 400 megabits per second (Mbps), making it perfect for high-bandwidth data—things like video. I'll talk about FireWire hardware later, but I have a Maxtor 3000XT external 160-GB FireWire hard drive, and I was extremely impressed with how fast it is and how easy it was to connect. Items connecting through FireWire can be "hot swapped," which means that you can connect a hard drive to your computer without powering it down first, and it will appear in your My Computer folder within seconds and be ready to use. FireWire devices require a FireWire port, which can be added easily using an Adaptec or ADS PCI card that plugs into your motherboard. Many new computers are shipping with FireWire ports, so be sure to check your computer manual to see if you have one.
USB 1.1 and 2.0
USB stands for "Universal Serial Bus," and it's a technology that allows external devices like floppy drives, printers, mice, keyboards, and dozens of other devices to be connected to a PC. USB devices are "hot swappable," which means that you can connect and disconnect them while the computer is running. USB 1.1 offered a meager 12 Mbps of bandwidth, which was enough for a mouse but not for high-performance external hard drives. USB 2.0 kicks the spec into overdrive, offering 480 Mbps of bandwidth and full backward compatibility with USB 1.1 devices. The older USB 1.1 devices don't perform at USB 2.0 speeds, but they work in the USB 2.0 hubs and ports. Some newer computers are starting to offer USB 2.0 ports, but it's easy enough to add them by installing a PCI card into your computer. Adaptec (www.getadaptec.com) makes a product called the DuoConnect, and it offers three USB 2.0 ports and two FireWire ports. I'll talk more about USB hardware later, but my tests with a Maxtor 3000LE USB 2.0 hard disc were very encouraging—I was able to move huge video files quickly, with sustained write speeds of 6.6 MBps and read speeds of 8.0 MBps.
Digital Audio File Types
A critical part of any video is the audio—unless your goal is to create a pantomime masterpiece, you'd be wise to pay attention to your audio track. Working with audio requires a basic knowledge of the file formats that you may encounter, so listed below are the most important ones.
- WAV A lossless file format, WAV files tend to be quite large (a typical song in WAV format will be 40+ MB in size), but they're very high quality and can be saved over and over without any data loss. WAV files are easy to work with in audio programs like Sonic Foundry's Sound Forge 6.0 (www.sonicfoundry.com), and all video-editing applications should accept WAV files as valid audio track sources.
- Windows Media Audio (WMA) A revolutionary file format from the Windows Media Team at Microsoft, WMA is a powerful format for digital audio. It offers MP3 quality in half the file size and bit rate. I take exception to the statement by Microsoft that they can offer "CD-quality sound" at 64 Kbps (it comes close at 96 Kbps), but there's no arguing that WMA is the superior format for low-bit rate audio. Unfortunately, many digital video programs can't accept WMA files as input, so you may need to have your original CDs on hand to get the song you need.
- MP3 Short for MPEG Layer 3, the granddaddy of all lossy audio compression formats, MP3 has been around since 1987, but it wasn't until almost 10 years later that it became popular with the advent of peer-to-peer file sharing services. MP3s offer reasonable quality sound at 128 Kbps in one-tenth the size of a similar WAV file, and that size savings is what makes it popular. Early MP3 files actually sounded horrible, but going from a 40 MB WAV file down to a 4 MB MP3 file was so amazing that people put up with it. Today, nearly every video-editing package can accept MP3 files as an audio track.
- MP3Pro A newer format, MP3Pro was created as an enhancement to MP3. It offers a superior psychoacoustic model, very similar to WMA. There doesn't appear to be much industry support for this format, however—the only encoder and player (www.mp3prozone.com) is still a demo limited to 64 Kbps, just as it was nearly a year ago. I haven't seen a video-editing program that can accept MP3Pro files, so I'd avoid this format completely.
- Ogg Vorbis Despite the strange name, this format offers a lot for the future of digital audio. Unlike any of the other compressed formats, it's completely free, open, and not patented (which is highly unusual in the technology industry). It's more interesting to developers than end users—if you have software that creates MP3s, you need to pay a royalty fee to Fraunhofer (the creators of the MP3 format). I'm not aware of any video-editing programs that accept Ogg Vorbis files as input, so this format is best to avoid for now. Over the next few years, however, it will be interesting to see how this evolves (www.vorbis.com).
- RealAudio Once the king of the streaming digital audio world, RealAudio isn't as popular as it once was. RealAudio is a good format for streaming audio, but for a high-quality audio track you'd be better served by going with another format. Most video-editing programs will not accept RealAudio as an input format. Avoid this format.
Digital Video File Types
Digital video has existed in various forms for over a decade now, so it's not surprising that multiple formats have popped up. It's not necessary to know a great deal about each format, but having a basic grasp of what each one is good for will help you when we discuss sharing your video in the latter part of the book.
- AVI Short-form for Audio Video Interleaved, this is the most common, and oldest, form of digital video on the PC platform. AVI files are essentially "containers" for video. Most AVI format videos are compressed with a codec. In most cases, unless an unusual codec is used, AVI files will play in the Windows Media Player without any problems. Unless you're using a powerful codec for compression (like the DivX coded from www.divx.com), your video files will tend to be quite large. AVI is a good format to archive your videos in—if my video projects aren't too large, I try to burn a copy of my source footage to a CD for keeping. With most standard codecs, saving to an AVI format is a lossless form of compression.
- Windows Media Video (WMV) A brother to the WMA format, WMV is a highly compressed video format that has taken the Web world by storm since being released in 2000. The WMV format uses special psychovisual codecs to discard data, resulting in a high-quality video in a surprisingly small file size. How small? I had a full DV-resolution AVI file (720 x 480) that was 408 MB in size. While maintaining a similar resolution (640 x 480), I was able to crunch that huge file size down into 19.8 MB! Unless I zoomed the video to 200 percent of normal size, I couldn't tell the difference between the two. The video data rate was 1506 Kbps, so it's certainly not meant for streaming, but a 20 MB download would go fairly quickly with a cable modem and give people a high-quality video to watch. As you can tell, I'm a big fan of the WMV format. We'll discuss how to create and share WMV format video files in Chapter 9. WMV is a lossy compression format.
- ASF A Microsoft format that was only around for a couple of years, Active Streaming Format (ASF) was designed primarily to be streamed over the Internet. ASF files will play in the Windows Media Player but you likely won't see them around very often—WMV has replaced ASF in almost every way.
- MPEG Short for Moving Picture Experts Group, MPEG has been around for a long time and is still the basis for many of the video formats on the market today. MPEG was the first format on the PC that allowed huge AVI files to be compressed to a much smaller size while still retaining decent quality, having been optimized for video playback from a CD-ROM at about 1.5 Mbps. MPEG video files can be viewed in the Windows Media Player, and most video-editing packages will output in some variation of MPEG. MPEG is a lossy compression format, and a good cross-platform way to share your video over the Internet.
- MPEG2 A variation on the original MPEG specification, this is a newer version that supports a new compression scheme, allowing for better-quality video. It was created to address the need for higher-quality digital video, specifically in the 4 to 9 Mbps range. DVDs use a form of MPEG2 video, as do some digital video cameras. MPEG2 files are saved using lossy compression and often have a .m2v file name extension. Most should play fine in Windows Media Player.
- MPEG4 Yet another offshoot of the original MPEG specification, MPEG4 was originally created specifically to target video at low bit rates. It has since evolved into a replacement for the original MPEG video format by targeting video from 64 Kbps and lower up to 4 Mbps. It won't replace the high-quality video on a DVD, but it offers some interesting options for storing and sharing video. Most of the video-editing packages on the market today don't support MPEG4 video, but there are stand-alone programs to create MPEG4-based content. Now here's where it gets a little confusing: Many of the video formats on the market today are MPEG4-based. QuickTime and RealVideo are both based on MPEG4 codecs. Each format simply "wraps" them up differently. It doesn't have much relevance to you as an end user, so I won't try to explain how they all relate to MPEG4. It's simply important to understand that MPEG4 technology is core to much of the streaming video that is happening right now.
- RealVideo Once the king of video streaming, RealVideo is still quite popular, but Windows Media and QuickTime formats have caught up and surpassed it in most ways. To play back RealVideo content you need the RealOne player from www.real.com, which makes it a poor choice for sharing video with others (because they have to download a special player to see your video). Most of the video-editing applications can't work with RealVideo content, and there are better formats for archiving. Although several applications I tested will output files in RealVideo format, I don't recommend you use this format at all.
- QuickTime QuickTime, the video format championed by Apple, has quite a few supporters in the industry. It's particularly popular with movie studios for releasing trailers on the Web. QuickTime video quality is outstanding, and it streams well over the Web. The biggest problem I have with QuickTime is the fact that their "free" player, upon loading, will frequently pop up an advertisement for QuickTime Pro, the professional version of QuickTime. A truly free player should not hassle the user to upgrade. That aside, QuickTime import and export is supported by several video-editing packages currently on the market. Because native QuickTime support is not included in Windows XP, if you e-mail someone an MOV file (the file format for QuickTime), that person might not be able to open it without downloading QuickTime from Apple (www.quicktime.com). Something to keep in mind!
- DivX The DivX format is a relatively new one, and it's technically not a video format unto itself: It's an MPEG4-based codec for the AVI format that creates highly compressed video while still retaining superb quality. There's a lot to like about DivX, including great quality and small file sizes, and the tools to create and watch DivX are free (www.divx.com). DivX claims over 60 million people are using their software, and it's quite popular for sharing movies (though, I should note, not legal). So what's not to like? Unfortunately, if you send people a DivX-format AVI file by e-mail or through the Web, when they try to play it with the Windows Media Player, they'll hear the audio but get no video (as I mentioned above when talking about codecs). When it's missing a codec that it needs, Windows Media Player has the ability to connect to the Internet and download the missing codec. For whatever reason, Microsoft doesn't offer the DivX codec, so whoever is viewing your video will have to go to www.divx.com and download their free software. Not difficult, but a hassle.
- VCD Short for VideoCD, this format emerged from the Asian markets, which didn't want to pay royalties to the DVD consortium for the ability to play back video on a DVD player. The format is based on MPEG1 video and supports 74 to 80 minutes of video on a standard 650/700 MB CD-R. VCDs are limited to 1150 Kbps for video at 352 x 240 pixels and 224 Kbps for audio. The quality of a VCD is roughly comparable to VHS tape—not bad, but not great, either. VCDs work on the vast majority of DVD players on the market today, and every new DVD player I've seen supports the format. If you don't have a DVD burner, VCDs are a great way to share your video with others. There's an offshoot of VCD called XVCD with a higher bit rate of 2500 Kbps, but it's an unofficial format and should be avoided for now. We'll go into how to create VCDs in Chapter 10, and with more and more software packages supporting VCD creation, it's extremely easy. A great source for learning about VCDs is www.vcdhelp.com.
- SVCD Short for Super VideoCD, this MPEG2-based format has a lot in common with VCDs. Support for SVCDs is increasing, but it's not quite as broad as VCDs when it comes to DVD playback. Still, if your DVD player can support it, this 2500 Kbps video format will give you excellent quality video. SVCD video is 480 x 480 pixels, so when you play it back on your computer it might look "squished." SVCD is an excellent and inexpensive format for sharing short videos. Several software packages support the creation of SVCDs, so we'll discuss how to make them in Chapter 10 when we get into how to share your videos using discs.
- DVD Perhaps the best-known term in the digital video world, DVD stands for Digital Versatile Disc, not Digital Video Disc as some believe. DVD players are becoming common in the average home, and the sales of DVD players are growing faster than VCRs ever did. The 9800 Kbps video bit rate and 720 x 480 resolution ensure extremely high-quality video, and the audio can support up to eight tracks containing Digital Theatre Sound (DTS), Dolby Digital, or regular Pulse Code Modulation (PCM) audio. A standard DVD can hold roughly 2 hours of digital video, but that number can change depending on the video's quality. Until recently, it was an expensive undertaking to create a DVD and out of reach for most consumers and small businesses. That has changed in the past few years, but there are two warring standards for DVD burning, which creates confusion and slows down the adoption of DVD burning as a solution. Things have gotten better in the past year, but I still find it frustrating that the computer industry can't unite behind a single format.
- DVD-R and DVD-RW DVD-R offers the greatest compatibility with stand-alone DVD players. It's the only format officially sanctioned by the DVD Forum, a collection of hardware and software manufacturers that are involved in creating standards for the DVD format (Hitachi, Pioneer, Sony, Toshiba, and others). DVD-RW is simply a rewriteable version of this format. DVD-R drives can support up to 4.7 GB capacities, and this type of DVD burner comes standard in many computers from Apple and Compaq. Look for Pioneer to release a 4X speed burner, twice as fast as their current drive, in the winter this year (2002).
- DVD+R and DVD+RW Although this format offers some advantages over DVD-R, it's slightly less compatible with stand-alone DVD players (for now at least). It does have the backing of electronics giant Philips, however, and DVD+R products are included in some of today's top-end PCs. DVD+RW is a rewriteable version of this format. DVD+R supports up to 4.7 GB of data on a single disc.
- DVD-RAM This format was created to allow DVDs to be used like a hard drive, specifically for data storage. DVD-RAM discs aren't compatible with stand-alone DVD players. The DVD Forum also supports this format. Current DVD-RAM drives can support up to 9.4 GB on double-sided discs.
There are other formats of digital video, including DVD-VCD and DVD-SVCD, but until they become more common they're not worth considering as viable choices for storing and sharing your video.
Digital Image File Types
Some of the video-editing packages I'll be talking about include support for image files, so it's important to understand what each image format offers.
- JPEG Sometimes referred to as JPG files, this format is what most digital cameras use for storing images. Offering 24-bit color and lossy file compression, JPEG files offer a good balance between quality and file size. Every time you save an image in JPEG format, you'll lose more data; so when you're editing JPEG images, make sure to save them only once and keep your original. Most video-editing packages support importing JPEG images to include in your video presentation. Videos with integrated still photos can be very interesting!
- BMP The bitmap file format is as old as Windows itself (perhaps older). It supports 24-bit color and offers no compression format, making it a good format for multiple saves but a poor choice for saving space. Most video-editing applications support BMP files, but you likely won't be using them very often.
- GIF The GIF format stands for Graphics Interchange Format and is limited to 256 colors, making it a very poor choice for photographs. You won't likely work with GIF images during video editing.
- TIFF Short for Tagged Image File Format, this format is still popular in the printing industry but fairly rare outside of it. TIFF images support a lossless compression scheme, but they still tend to be quite large. Supporting 24-bit color, the TIFF format is a high-quality image format, but it's unlikely to be used much in the video-editing packages we'll be looking at.
- PNG This 24-bit color format stands for Portable Network Graphics, and although it's technically very superior in what it offers (24-bit color, transparency, lossless compression), adoption of this format has been slow. Some editing packages support the PNG format, but in most cases you won't be using this file format.
Key Points
- Windows XP includes several tools for digital video users.
- Digital video is compressed to conserve space.
- There are two types of digital compression: lossy and lossless.
- FireWire and USB 2.0 are high-speed data transfer protocols important to digital video.
- DVD-R and DVD+R are the two main standards fighting for dominance.
- JPEG images are the most common images you'll work with in digital video.
Last Updated: November 13, 2002
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