Apple Compressor 3 - Manual (Page 185)

• Purpose buttons: Choose the intended purpose for the output files.
• Web: Forces the resolution to 320 x 240 regardless of the Frame Rate selection.
• DVD: Allows the Frame Rate selection to set the resolution. With the 29.97 frame
rate, the resolution is 352 x 240. With the 25 frame rate, the resolution is 352 x 288.
• Bit rate: Use this slider to choose the bit rate to use for the output video, or enter a
number directly into the text field. While the available range is from 0.5 Mbps to
2.0 Mbps, the actual setting you should use depends on how the output is to be used.
Higher bit rates produce better picture quality, but they also produce larger output
files.
• For web projects: Choose a bit rate that best balances the picture quality with file size
and download expectations.
• For VCD projects: The recommended video bit rate is 1.15 Mbps, with a system stream
(multiplexed video and audio in the same file) bit rate of under 1.3944 Mbps.
• For DVD projects: The typical video bit rate is 1.15 Mbps, with 1.856 Mbps being the
maximum allowed.
About the MPEG-1 Audio Tab
You use the Audio tab to make settings related to the audio format.
• Enabled checkbox: Make sure this checkbox is selected if you want the MPEG-1 output
format to include the Audio tab settings.
• Sample Rate pop-up menu: Choose the sample rate of the output audio.
• 48 kHz: Required for use on DVDs.
• 44.1 kHz: Used on audio CDs. This is the most commonly supported sample rate.
185 Chapter 17 Creating MPEG-1 Output Files