Interactive PDF depends heavily on the reader application being used. How are you testing this? What version of InDesign is being used? What operating system? What format is the video?
Windows 10, InDesign C6, Acrobat Reader DC, mp4
You may use button and add action like play pause resume and stop to the PDF.
To do that please follow these steps:
1) Place video on the docuemnt
2) Create Button
Use the Pen tool or a drawing tool, such as the Rectangle tool or Ellipse tool, to draw the button shape. If necessary, use the Type tool to add text to the button, such as “Play” ,“Pause" , "Resume"and "Stop".
Highlight object say text frame that says "Play" and got to choose Window > Interactive > Buttons
In Buttons and Forms menu
Type as Button
Event as On Click
Then click + in front of action and choose Video
It will automatically select video placed on document.
then choose Play from Options
And you can do the same for "Pause" , "Resume"and "Stop".
For more details and options on buttons you may check below mentioned link.