how can i stop video from playing if not point view

问题

js to play videos in my site

but i wanna stop playing the video if not in view point

i make this code

$(document).on("scroll", function() {
  var scrollTop = $(window).scrollTop();
  $( "video" ).each(function() {
    var pos = index.position();
    if (scrollTop < pos.top + 100) {
                $(this)[0].play();
    }
    if (scrollTop > pos.top + 400) {
                $(this)[0].stop();
    }
    if (scrollTop < pos.top - 400) {
                $(this)[0].stop();
    }
  });
});

but it not work for me and not show any error

this is demo page "http://jsbin.com/yaqozihita/1/"

回答1:

You can use this code to detect if an element is in view or not. Iterate each video element, if isInView() is true, start video, if not pause it if not paused already.

Caveats: you need to make sure the video has loaded at least metadata or the video element may cause errors. Use preload="auto" and the canplay event to detect this stage in advance (not shown here).

function isInView(el) {
  var rect = el.getBoundingClientRect();           // absolute position of video element
  return !(rect.top > $(window).height() || rect.bottom < 0);   // visible?
}

$(document).on("scroll", function() {
  $( "video" ).each(function() {
    if (isInView($(this)[0])) {                    // visible?
      if ($(this)[0].paused) $(this)[0].play();    // play if not playing
    }
    else {
      if (!$(this)[0].paused) $(this)[0].pause();  // pause if not paused
    }
  });  
});

div {width:400px;}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div>
<h1>Scroll down to start video</h1>
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  <video loop style="width:320px;height:auto;">
    <source src="http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4" type="video/mp4">
        <source src="http://clips.vorwaerts-gmbh.de/big_buck_bunny.webm" type="video/webm">
            <source src="http://clips.vorwaerts-gmbh.de/big_buck_bunny.ogv" type="video/ogg">
  </video>

<br><br>
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    <video loop style="width:320px;height:auto;">
    <source src="http://www.html5rocks.com/en/tutorials/video/basics/devstories.mp4" type="video/mp4">
        <source src="http://www.html5rocks.com/en/tutorials/video/basics/devstories.webm" type="video/webm">
  </video>
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</div>

回答2:

for Pause use:

$(this)[0].pause();

for Play use:

$(this)[0].play();

tested on firefox and chrome

来源：https://stackoverflow.com/questions/29518546/how-can-i-stop-video-from-playing-if-not-point-view