Exporting, compressing, and hosting FLV files

You can export FLV files from Adobe® Flash® CS3 Professional authoring environments. After you import video into your document, it appears as a video symbol in the library. To export the video as FLV, select the video and then select Library > Properties. To make export settings, click Export in the Embedded Video Properties dialog box.

The FLV QuickTime Exporter compresses video from third-party video editing software. You can also use Flash 8 Video Encoder, which is a stand-alone application that you can use to create FLV files. Because you have a lot of control over the export settings, the quality of the FLV file that is created using either of these tools is better than video exported directly from Flash.

When you compress video, remember the following recommendations:

• Do not recompress video.

  Recompressing video leads to quality degradation, such as artifacts. Use raw footage or the least compressed footage that is available to you.

• Make your video as short as possible.

  Trim the beginning and end of your video, and edit your video to remove any unnecessary content. This can be accomplished directly in Flash using the Video Import wizard.

• Adjust your compression settings.

  If you compress footage and it looks great, try changing your settings to reduce the file size. Test your footage, and modify it until you find the best setting possible for the video you are compressing. All video has varying attributes that affect compression and file size; each video needs its own setting for the best results.

• Limit effects and rapid movement.

  Limit movement if you are concerned about file size. Any kind of movement, particularly with many colors, increases file size. For example, effects (such as cross fades, blurs, and so on) increase file size, because the video contains more information.

• Choose appropriate dimensions.

  If your target audience has a slow Internet connection (such as phone modems), make the dimensions of your video smaller, such as 160x120 pixels. If your visitors have fast connections, you can make your dimensions larger (for example, 320x240 pixels).

• Choose appropriate frames per second (fps).

  If you target users that typically have older computer processors, choose a low rate of frames per second (such as 7 or 15 fps). If you target users with newer computers, you can use a higher rate of frames per second (such as 15 or 30 fps). Always choose an fps that is a multiple of your original frame rate. For example, if your original frame rate was 30 fps, compress to 15 fps or 7.5 fps.

• Choose an appropriate number of keyframes.

  Video keyframes are different from keyframes in Flash. Each keyframe is a frame that draws when the video is compressed, so the more frequent your keyframes are the better quality the footage is. More keyframes also mean a larger file size. If you choose 30, a video keyframe draws every 30 frames. If you choose 15, the quality is higher because a keyframe draws ever 15 frames and the pixels in your footage are more accurate to the original.

• Reduce noise.

  Noise (scattered pixels in your footage) increases file size. Reduce noise using your video editor, to reduce the video file size. Using more solid colors in your video reduces its file size.

  When you put FLV files on a server, they use the video/x-flv FLV mime type. If you have difficulty viewing FLV files after you upload your files, check that this mime type is set on your server. FLV files are binary, and some applications that you build might require that the application/octet-stream subtype is also set. For more information on the Flash Player specifications, see www.adobe.com/go/flashfileformat.