> H.264/AAC (MPEG-4) Customization
> When you customize Web-High and Web-Low presets, ScreenFlow displays the H.264/AAC compression settings dialog (Figure 64).
> Figure 64. H.264/AAC Settings Window
> Set these options, as described below in Table 16. When you’re done, click OK.

> Table 16. H.264/AAC (MPEG-4) Settings
> Option | Description
> H.264 Video | Uncheck when you do not want your exported file to contain video tracks.
> Frame rate | Enter the frame rate in frames per second, or select preset values from the popup menu.
> Data rate | Enter the data rate in kbits per second. NOTE: The data rate you enter is a target value. Therefore, the actual data rate may be higher or lower than entered.
> Profile | Select the codec profile (which establishes parameter ranges for a given application) from the popup menu:
> Automatic | The codec determines which profile to use, based on the size of the input video.
> Main | This profile results in longer encoding; it was designed primarily for SD digital TV broadcasts. It is well-suited for playback on desktop computers.
> Baseline | This profile is used for faster, simpler encoding, and improved data loss robustness, particularly for playback in mobile applications.
> Keyframe Rate | Select automatic or fixed keyframe rate
> Automatic | Screenflow selects the optimum rate
> Fixed every | Manually enter the frame rate
> AAC Audio | Uncheck when you do not want your exported file to contain audio tracks.
> Sample Rate | Select to signify the number of samples taken from the source per second (in kHz) and added to the audio track being generated. Select the sample rate from the popup menu. Web-High and Web-Low, defaults to CD quality (44.1 kHz).
> Data rate | Enter the data rate in kbits per second. Web-High, defaults to 256kbits/sec. Web-Low, defaults to 96kbits/sec.
> Channels | Select Mono or Stereo