<body>
<video controls name="media" src="1.mp4"></video>
<video controls name="media" src="2.mp4"></video>
<video controls name="media" src="3.mp4"></video>
</body>
document.querySelectorAll('video').forEach(
el => el.addEventListener('play', function(event) {
console.log(this)
})
)document.addEventListener('play', function(event) {
console.log(event.target)
}, true) /* обязательно! */