Set a poster frame in Compressor
The poster frame is a still image that represents a video or audio media file.
Note: When viewing the output file in Apple TV Home Videos, if no poster frame is set, Apple TV Home Videos automatically uses the frame 10 seconds from the movie’s first frame as the poster frame.
Set the poster frame for a job
In Compressor, select the job that contains the source file that you want to set a poster frame for.
In the preview area, position the timeline playhead
at the frame you want to be the poster frame.Click the arrow next to the Marker button
, then choose Set Poster Frame.
A poster frame marker 
appears in the timeline.
After you set a poster frame, you can jump to that frame at any time by clicking the arrow next to the Marker button , then choosing Go to Poster Frame.
Remove the poster frame
In the Compressor preview area, click the arrow next to the Marker button
, then choose Clear Poster Frame.
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