revision:
The onprogress event occurs when the browser is downloading the specified audio/video.
Supported HTML tags: <audio>, <video>.
During the loading process of an audio/video, the following events occur, in this order: onloadstart, ondurationchange, onloadedmetadata, onloadeddata, onprogress, oncanplay, oncanplaythrough.
<element onprogress="script"></element>
script: this attribute contains a "single value script", which works when the onprogress event attribute is called.
example 1
<video style="margin-left:3vw;" width="300" height="auto" controls onprogress="videoDown()">
<source src="../../pics/Wuzhen-20-10_02.mp4" type="video/mp4">
Your browser does not support HTML5 video.
</video>
<script>
function videoDown() {
alert("downloading video");
}
</script>
example 2
<audio style="margin-left:3vw;" controls onprogress="audioDown()">
<source src="../../pics/horse.wav" type="audio/wav">
Your browser does not support the audio element.
</audio>
<script>
function audioDown() {
alert("downloading audio");
}
</script>