Inténtalo tú mismo - JavaScript Reference onseeking

<!DOCTYPE html>
<html>
<body>

This example shows the difference between the onseeking event and onseeked event.

The onseeking event occurs everytime the user STARTS moving/skipping to a new position in the audio/video.

The onseeked event occurs when the user is FINISHED moving/skipping to a new position in the audio/video

Move to a new position in the video. Tip: Try to hold down the mouse button and seek back and forth in the video playback.

<video controls onseeking="myFunction()" onseeked="mySecondFunction()">
 <source src="mov_bbb.mp4" type="video/mp4">
 <source src="mov_bbb.ogg" type="video/ogg">
 Your browser does not support HTML5 video.
</video>

seeking occured: times.
seeked occured: times.

y = 0;
function mySecondFunction() {
 document.getElementById("demo2").innerHTML = y += 1;
}
</script>

</body>
</html>