Compressing the Goods (page 2)

Basic Ideas for the Home

For videographers who want to e-mail video and use online video-sharing sites such as YouTube, here are a few ideas for better video. While e-mailing video is private and as simple as attaching a photo, some hurdles are present. Current limitations include how much an e-mail account will allow you to send and which video formats the e-mail recipient may play back. Many e-mail accounts top out at 10 megabytes for attachments. Though it doesn't seem like much at first, it'll allow a couple minutes of compressed video, enough for a thoughtful video greeting card, the winning goal or a baby's first steps. When compressing for e-mail, reducing the resolution in half helps keep the file size to a minimum. Use a resolution of 400x225 pixels for widescreen DV video, 320x240 pixels for standard DV video and 960x540 pixels for high-definition video. Keeping your video at 30fps (full-motion video) will create the smoothest motion. If you need to reduce the file size even more, reducing the frames-per-second will help tremendously, but you'll want to use it as a last resort. As a general rule, cutting the videos frames-per-second in half, from 30 to 15fps, will reduce the file size in half as well. The resulting video may seem to stutter as it plays, but it may be the only way to send it as an attachment.

Web sites like YouTube offer unparalleled capabilities for sharing video with large numbers of people. If you want to send longer videos and to more people than you can access through e-mail, consider compressing for a video-sharing site. YouTube automatically compresses your video for playback on its Web site as Flash video. Your video must be under 100MB, though, which means you'll have to find a good way to get that 1-gigabyte video down to size. For the best results, aim to compress your video so that it just fits the 100MB file size requirement. Many video-editing applications have the tools built in to compress your video to a variety of formats for the Web. If you don't already have the tools and you want to use the H.264 codec, you could use QuickTime Pro (available for a fee at www.apple.com/quicktime) to compress video using the H.264 setting. It's not mandatory to use H.264; you could also try one of the other recommended settings found at www.youtube.com/help. At one time, people thought it would be an advantage to compress video into the Flash video format that YouTube uses natively, but YouTube simply compresses every video that's uploaded, whether it's a Flash video or not. Luckily for us, YouTube now letterboxes any widescreen video, which subtracts a step from the task of compression.

Basic Techniques for the Home

To refine the process of compression, we'll take a page from the still photographer's darkroom. In the traditional darkroom, the photographer slices his photo paper into thin strips. He uses these slices to determine how the larger print will turn out. If there is an error, he's wasted only a small amount of paper. This technique translates when compressing video for the Web. Since compressing video takes practice, you can select a few minutes of the longer video to compress, as a test. This way, if you compress using a setting of 800kbps (kilobits per second), and its visual quality proves unsatisfactory, you can make another attempt at 1200kbps shortly after. This technique drastically reduces the time to make a great compressed video, since you don't have to wait for the entire 43-minute documentary on your Father's WWII service to finish "cooking."

Basic Ideas for the Small Biz

If you've found your stride as a videographer, and you're looking to attract paying clients, compressing for e-mail and video-sharing sites doesn't offer the flexibility you need. Think about starting a personal Web page, where you can include large videos that play back smoothly. Variable bitrate recording (VBR) trumps constant bitrate recording (CBR) in most compression situations. You can find these in the Adobe Media Converter (part of Adobe Premiere 3.0), as well as QuickTime Pro. VBR allows the bitrate to change and adjust for more bits per second for more challenging parts of the visual image. In this mode, you set the maximum bitrate, and the software will reduce the bitrate when it sees it's not needed, allowing the file size to reduce even more. Two-pass VBR may take up to twice as long to compress, since it typically scans your video once before going over it a second time to complete the compression. Be ready to fix a snack.

Determine what video player your clients use and make something that caters to them, so they aren't stuck fussing with an unfamiliar video player. For example, if they're used to their Windows Media Player, make them a Windows Media file. The same goes for QuickTime and Flash video.