With the internet and mobile devices becoming popular methods for the delivery of video content, a few tips can go a a long way to help improve the quality of video before it undergoes the necessary video compression for upload to the web or mobile devices. This article is published at the Adobe Developer Center.

Capturing Good Video

In addition to the physical properties of your video there are a variety of factors that affect the efficiency of the encoder and, ultimately, the user experience of the video playback. Two factors play a significant role in the encoding process: source quality and frame motion.

Source Quality

You determine the source quality of your video as soon as you press the recording button on your camera. The following are some basic guidelines for getting great source video quality and maximizing quality in your final compressed video.

Use a tripod to reduce camera movement. If your camera is not steady, most of the image moves, causing a high percentage of pixels in the video to change from frame to frame. A steady camera reduces the number of pixels that change from frame to frame, giving you better quality at higher compression rates (lower data rates).

Use good lighting techniques. A high-end camera resting on a tripod can still produce a low-quality image if there is not enough light. Low-light or light-gain filters produce video noise on the image. This noise is different for each frame of video and makes it difficult for the codec to compress the file at a good quality. You may need to use or exceed your maximum data rate to compensate for video noise.

Use the best camera possible. Low-grade cameras specifically consumer-based ones that record an analog signal on magnetic tape (VHS, Hi-8, and so on)produce much video analog noise. Still digital cameras in movie mode also have limited quality and generally produce high-noise video clips. Even if the camera is on a tripod, with excellent light, it will produce noise.

Do the best you can with what you have to work with. High-end digital cameras, digital Betacam camcorders, and 35mm film cameras produce a clean image if the scene is well-lit and they are stabilized by a tripod. Such a scenario produces the best compression ratio and lets you reduce the data rate while maintaining excellent quality. However, you may not have access to professional equipment, a tripod, and excellent lighting conditions. Just remember: the higher the quality of your video source, and the less noise in that source, the lower the data rate required to render a good playback file.

Whenever possible, always encode a file from its uncompressed form. If you convert a precompressed digital video format into the FLV format, the previous encoder can introduce video noise. The first compressor has already performed its encoding algorithm on the video and has already reduced its quality, frame size, and rate. It may have also introduced some of its own digital artifacts or noise. This additional noise affects the FLV encoding process and may require a higher data rate to play back a good-quality file.

Frame Motion

Frame motion is another factor to consider in your encoding formula. It is the percentage of the pixels that change from one frame to another. This change can result from a person or object moving, camera effects, or post-production effects, such as the following:

• People and objects moving can include someone walking past the lens, tree leaves blowing in the wind, cars driving by, or an extreme close-up of a face.

• Camera effects such as camera panning, zooming, or hand-holding result in almost 100% pixel change from frame to frame.

• Postproduction effects such as dissolves, fades, wipes, or complex video effects result in a high percentage of pixel changes from frame to frame.

The greater the motion within your video clip, the more information the encoder has to compress. If your clip is relatively still (such as a talking head video), there isn’t much pixel change from frame to frame. The video compressor uses a method of dropping frames and then encoding a series of fully uncompressed frames. These uncompressed frames, called keyframes, are used to calculate and “rebuild” the missing frames during playback.

For the complete Flash video guide visit: http://www.adobe.com/devnet/flash/articles/video_guide_02.html

Source: Adobe.com