You can add video and audio—a music file, a playlist from your iTunes library, or a sound clip—to a document. Click the Play button on the video or audio on the page to watch or listen to it.
Note: Video and audio files must be in a format that QuickTime supports on your Mac. If you can’t add or play an audio or video file, try using iMovie, QuickTime Player, or Compressor to convert the file to a QuickTime file, in MPEG-4 audio or H.264 (720 p) video format.
Do either of the following:
Drag a media file from your computer to a media placeholder or to anywhere else on the page.
Click 
in the toolbar, select Photos, Music, or Movies, then drag the file to a media placeholder or to anywhere else on the page.
To search for media, click the magnifying glass in the upper-right corner of the media window.
You can choose the frame that is displayed on a page before the video starts playing.
Select the video on the page.
Click the Movie tab at the top of the sidebar on the right.
If you don’t see a sidebar, or the sidebar doesn’t have a Movie tab, click 
in the toolbar.
Click the disclosure triangle next to Edit Movie.
Drag the Poster Frame slider to choose the frame.
Select the audio or video object on the page.
Click the Audio or Movie tab at the top of the sidebar on the right.
If you don’t see a sidebar, or the sidebar doesn’t have an Audio or Movie tab, click in the toolbar
Click Replace.
Select an audio or video file (you may have to open a folder first), then click Open.
You can trim media, set playback volume, and set video and audio to repeat in a loop.
Select the audio or video file on the page.
Click the Movie or Audio tab at the top of the sidebar on the right.
If you don’t see a sidebar, or the sidebar doesn’t have a Movie or Audio tab, click in the toolbar.
Do any of the following:
Adjust playback volume: Drag the volume slider.
Trim the audio or video: Click the disclosure triangle next to Edit Audio or Edit Movie, then drag the Trim slider.
Loop the audio or video: Click the Repeat pop-up menu and choose an option. Choose Loop to have the media play until you move to the next page. Choose Loop Back and Forth to have it continually play forward then backward until you move to the next page.
You can set a preference in Pages to automatically convert movies in your document to H.264 (720 p) so they play on iOS devices.
Choose Pages > Preferences (from the Pages menu at the top of your screen).
Click General at the top of the preferences window, then select the checkbox next to “Optimize movies for iOS.”