Edit video and audio in Keynote on Mac
After you add video or audio to a slide, you can set it to repeat in a loop, play continuously through multiple slides or change its start timing in your presentation. You can also trim it to play only part of the video or audio and adjust its playback volume in your presentation. For a video, you can change the poster frame that’s displayed on a slide to represent the video.
Set video or audio looping and start timing
Click to select the video or audio on the slide.
In the Format sidebar, click the Movie or Audio tab.
To set when the video or audio starts playing on the slide, choose one of the following:
When you click: Select the tick box next to “Start movie on click” or “Start audio on click”.
Automatically when the slide appears: Deselect the tick box next to “Start movie on click” or “Start audio on click”.
Through multiple slide transitions: Select the tick box next to “Play movie across slides” or “Play audio across slides”. Videos and audio now play continuously even if you change their size and position between consecutive slides. For additional information and templates related to playing video and audio through slide transitions, see this Apple Support article.
Restart when a new slide appears: Deselect the tick box next to “Play movie across slides” or “Play audio across slides”.
To set media to repeat until you advance the slide, click the Repeat pop-up menu, then choose how you want it to play:
Play in a continuous loop: Choose Loop.
Play forward and then backward: Choose Loop Back and Forth.
Note: Recorded audio can’t loop back and forth.
Trim video or audio
Click to select the video or audio on the slide.
In the Format sidebar, click the Movie or Audio tab.
Click the disclosure arrow next to Edit Movie or Edit Audio, then drag the Trim sliders.
Note: You can’t trim audio that you recorded in Keynote on your iPhone or iPad.
Change the poster frame for a video
You can choose the frame that’s displayed on a slide to represent the video.
Click to select the video on the slide.
In the Format sidebar, click the Movie tab.
Click the disclosure arrow next to Edit Movie, then drag the Poster Frame slider.
Adjust playback volume
Click to select the video or audio on the slide.
In the Format sidebar, click the Movie or Audio tab.
Drag the Volume slider.
To work with multiple videos or audio objects at the same time, hold down the Shift key while you click the objects.
You can set Keynote to optimise the format and quality of movies and images you add to presentations.