Create an interlaced H.264 encoding setting in Compressor 4.2.1
You can create a custom setting to easily encode interlaced H.264 media.
Use these steps to create an interlaced H.264 encoding setting in Compressor 4.2.1.
In the Settings pane (Command-Shift-1) choose New Setting from the Add Setting pop-up menu.
In the window that appears, choose the "QuickTime Movie" transcoding format from the pop-up menu.
Enter a name and description for the setting, then click OK. The new setting appears in the Custom area of the Settings pane.
To modify the properties of your new custom setting, click the Video Inspector to adjust the controls. If the inspector is hidden, click the Inspector button in the upper-right corner of the Compressor window.
In the Video Properties section of the Video Inspector, click the Change button next to "QuickTime settings" to see the standard Video Compression Settings window.
Choose "H.264" from the Compression Type pop-up menu.
In the Compressor section select the option for "Faster encode (Single-pass)" encoding and click OK.
From the Video pane in the Inspector, select the interlaced field order you want (Top First or Bottom First) using the Field order pop-up menu.