Adobe Premiere Pro CS4 - Manual (Page 436)

430 USING ADOBE PREMIERE PRO CS4
Exporting
Last updated 11/6/2011
• Limit effects and rapid movement. Limit movement if you are concerned about file size. Any movement,
particularly with many colors, increases file size. Shaky camera work and zooms increase the size greatly. Some
effects increase file size because of the information they add to the video. On the other hand, some effects, such as
blurs, can be used to decrease the number of bits in a compressed file.
• Determine the range of hardware and software configurations available in your audience, and identify the limits of
the least-capable configuration. This way, you can set the frame rate low enough for smooth playback, and retain
as much quality as possible.
• 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.
• Choose appropriate frame dimensions. If your target audience has a slow Internet connection (such as phone
modems), make the dimensions of your video smaller, such as 160 x 120 pixels. If your audience has fast
connections, you can make your dimensions larger (for example, 320 x 240 pixels). Generally, it’s best to specify a
multiple of the full screen size, taking into account the pixel aspect ratio. For example, if the full screen size is 640
x 480 (square pixels), then try 320 x 240.
• Choose appropriate frame rate. If you target users that typically have older computer processors, choose a low rate
of frames per second (fps), such as 7 or 15 fps. If you target users with newer computers, you can use a higher frame
rate, such as 15 or 30 fps. Always choose a frame rate 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.
• If permitted by the codec, adjust the data rate and quality settings according to your output goal. For example, codecs
like Cinepak and Sorenson let you adjust the amount of compression by specifying a quality or target data rate.
• Lower the color depth if the source video contains less than the full range of colors. The full range is called 24-bit
color, Millions of Colors, or True Color. It is also effective for video shown on a monitor, or with software, that
displays a limited range of colors.
• Choose an appropriate number of keyframes. Video keyframes are different from keyframes in Adobe Flash
Professional projects. Each video keyframe is a full frame that is drawn when the video is compressed. The more
frequent your keyframes, the better quality the footage is. More keyframes also mean a larger file size. If you choose
30, a video keyframe is drawn every 30 frames. If you choose 15, the quality is higher because a keyframe is drawn
every 15 frames.
• 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. You can use the Video Noise
Reduction filter in the Adobe Media Encoder, or a soft blur in After Effects to help reduce noise.
• Choose a file type and codec appropriate for the target audience. For example, in the Export Settings dialog box you
can choose the Windows Media format for an audience primarily made up of Windows users. They all have the
Windows Media Player that can play this format.
• Test the file by playing it on a system comparable to the least-capable system in your intended audience, and make
adjustments accordingly.
Note: Applying a noise reduction filter can improve the appearance of video compressed with certain codecs, such as
Cinepak.