Now that I have covered pre-encoding acquisition tips and techniques, let me now address things you need to consider during the encoding process:
- A higher-target bandwidth (also known as data rate) allows for more motion in the video, larger files, better frame rates, and larger pixel dimensions.
- The less motion there is in your video, the better the clip will compress, and the smaller the ultimate file size will be. This also lowers your potential target bandwidth.
- The less motion in the video, the lower the frame rate can be without producing jerky and uneven playback. Lower frame rates produce smaller files, independent of compression ratios, because they contain less information per second of playback.
- As the target bandwidth decreases, reduce the keyframe rate. A lower keyframe rate (such as one keyframe every six seconds) will result in a softer or blurrier image, but reduces the bandwidth demand.
- As motion increases, you must increase the keyframe rate, the frame rate, and the data rate. High-motion clips, such as those used in sports footage, require more information to stream to the player and are unsuitable for low-bandwidth delivery because they require additional uncompressed keyframes to be encoded in the file.
- Reduce frame size when bandwidth is limited and frame rate and quality are important.
- If the video source you are encoding comes directly from a video camera, always enable de-interlacing and set the Flash Video Encoder to the upper field. If your video is interlaced, selecting this option increases the performance of the video encoding and playback.