Flash Video Encoder User Guide

Flash Video Encoder User Guide > Understanding video standards and terminology > Aspect ratios (frame size)

Aspect ratios (frame size)

As with the frame rate, the aspect ratio (or frame size) for your document is important for producing high-quality video. At a specific data rate (connection speed), increasing the frame size results in decreased video quality. When you select the frame size for your document, consider the frame rate, the aspect ratio of the source video clip, and your personal preferences to create a successful video presentation. Standard video display resolutions on the Internet include 640 x 480, 512 x 384, 320 x 240, and 160 x 120 pixels.

The most common aspect ratio is 4:3 (standard television). Increasingly, 16:9 and 2:1 (wide screen) aspect ratios are becoming more commonplace as well. Typically, you should encode the video using the same aspect ratio at which it was originally captured. Altering a video clip's aspect ratio may result in a distorted video image. An exception to this practice is when encoding digital video (DV) formats, whose aspect ratio is slightly different than the 4:3 aspect ratio because DV uses rectangular pixels. When encoding video content captured with a digital video camera, you must manually specify the frame size of the DV format you are using to preserve the video's aspect ratio. For more information see, Encoding video with non-square pixels.

The following list of standard frame sizes can be used as a guideline. You can experiment to find the best setting for your project.

Frame sizes for 4:3 aspect ratio video:

• Modem (56k): 160 x 120
• DSL: 320 x 240
• Cable: 512 x 384
• Cable/corporate LAN: 640 x 480

Frame sizes for 16:9 aspect ratio video:

• Modem (56k): 192 x 108
• DSL: 384 x 216
• Cable: 448 x 252
• Cable/corporate LAN: 704 x 396

Flash CS3