How do I detect if the HTML5 autoplay attribute is

2019-01-13 18:45发布

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问题:

How do I best detect whether a browser's HTML5 video element supports autoplay?

On current iOS Safari, for example, autoplay is disabled.

Update: I now designed the web page in such a way that it works irrespective of whether autoplay is supported. Now when the page is loaded an initialization video is shown. On an iPad, the user is presented with a big play button. Once playback has been triggered, the video is hidden. Afterwards, playback of the video player can be controlled from JavaScript, which is what I actually need.

回答1:

A little late to the party, but the accepted solution seems outdated: Modernizr now has implemented this feature, see https://github.com/Modernizr/Modernizr/blob/master/feature-detects/video/autoplay.js

Contains similar hacks to the other solutions posted here though, but as long as browsers don't expose availabilty of this feature, this seems to be the best solution for now.

Note that this an async test available since Modernizr 3, so you have to use the following .on() syntax for your test:

Modernizr.on('videoautoplay', function(result){
  if(result) {
    alert('video autoplay is supported');
  }  else {
    alert('video autplay is NOT supported');
  }
});

See for yourself: http://codepen.io/anon/pen/VYoWWY?editors=001

The above sample includes Modernizr 3 with the 'videoautplay' feature detection (http://v3.modernizr.com/download/#-videoautoplay).

回答2:

Maybe this will help future googlers like myself - this function creates/removes a video and tests to see if it can autoplay. It then sets a global variable "autoplay" to true or false. It tests for MP4 and webM compatibility, but adding more wouldn't be difficult if need be (just base 64 encode and append another source). The "acceptable delay" variable is how long it should reasonably take the device to start playing the test videos. With a combination of limited bandwidth/processing sometimes it makes sense to use the fallback (non autoplay) solution, even if autoplay is supported. I usually use 100ms.

function detect_autoplay(acceptable_delay){

    autoplay = false;  

    var autoplay_test_content = document.createElement('video');

   //create mp4 and webm sources, 5s long
        var mp4 = document.createElement('source');
        mp4.src = "data:video/mp4;base64,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";

        var webm = document.createElement('source');
        webm.src = "data:video/webm;base64,GkXfo49CgoR3ZWJtQoeBAUKFgQEYU4BnAQAAAAAAF60RTZt0vE27jFOrhBVJqWZTrIIQA027jFOrhBZUrmtTrIIQbE27jFOrhBFNm3RTrIIXmU27jFOrhBxTu2tTrIIWs+xPvwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA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   //append sources to test video 
        autoplay_test_content.appendChild(webm);
        autoplay_test_content.appendChild(mp4);

  //set attributes -needs to be visible or IE squawks, so we move it way outside  
    autoplay_test_content.id = "base64_test_video";
    autoplay_test_content.autoplay = true;
    autoplay_test_content.style.position = "fixed";
    autoplay_test_content.style.left = "5000px";

  //add to DOM       
    document.getElementsByTagName("body")[0].appendChild(autoplay_test_content);


    var base64_test_video = document.getElementById("base64_test_video");

  //test for autoplay, 100 ms buffer   
    setTimeout(function(){
        if(!base64_test_video.paused){
            autoplay = true;
        }

        document.getElementsByTagName("body")[0].removeChild(autoplay_test_content);

    },acceptable_delay);

}

detect_autoplay(100);

回答3:

As far as I can tell, neither Modernizr nor Dive into HTML5’s detection guide know how to detect whether autoplayis supported. (Although Modernizr’s “Undetectables” page doesn’t list autoplay either.)

I’ve popped up a test page which alerts the value of the autoplay property on a newly-created <audio> element, and both Safari on iOS 4.3 and Chrome 13 on Mac OS X return false (as opposed to undefined, which is what IE 6 returns).

So, unfortunately, your best bet might be to resort to browser detection, and maintain your own list of which browsers support autoplay.

回答4:

Here's an alternative solution that uses a callback and session storage to test for HTML5 video autoplay support. Once the test is preformed and the session storage exist the check isn't preformed again until the next session. This saves from running this every time a page loads. It uses a base64'd 1 second blank video clip to test for autoplay support.

https://gist.github.com/nathansearles/271870d4100f0f045c5c

    // isAutoplaySupported(callback);
    // Test if HTML5 video autoplay is supported
    isAutoplaySupported = function(callback) {
      // Is the callback a function?
      if (typeof callback !== 'function') {
        console.log('isAutoplaySupported: Callback must be a function!');
        return false;
      }
      // Check if sessionStorage exist for autoplaySupported,
      // if so we don't need to check for support again
      if (!sessionStorage.autoplaySupported) {
        // Create video element to test autoplay
        var video = document.createElement('video');
        video.autoplay = true;
        video.src = 'data:video/mp4;base64,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';
        video.load();
        video.style.display = 'none';
        video.playing = false;
        video.play();
        // Check if video plays
        video.onplay = function() {
          this.playing = true;
        };
        // Video has loaded, check autoplay support
        video.oncanplay = function() {
          if (video.playing) {
            sessionStorage.autoplaySupported = 'true';
            callback(true);
          } else {
            sessionStorage.autoplaySupported = 'false';
            callback(false);
          }
        };
      } else {
        // We've already tested for support
        // use sessionStorage.autoplaySupported
        if (sessionStorage.autoplaySupported === 'true') {
          callback(true);
        } else {
          callback(false);
        }
      }
    }

    // Usage: isAutoplaySupported(callback);
    // Using a callback assures that support
    // has been properly checked
    isAutoplaySupported(function(supported) {
      if (supported) {
        // HTML5 Video Autoplay Supported!
        console.log('HTML5 Video Autoplay Supported!');
      } else {
        // HTML5 Video Autoplay Not Supported :(
        console.log('HTML5 Video Autoplay Not Supported :(');
      }
    });

回答5:

The reason why the script above and the Modernizr-detection isn't reliable might be that they are not passing all the restrictions that Apple made:

The video must be muted
The video must be set to play inline
The video must have a size (0x0 px will fail)
The video must be visible in the viewport (no opacity-effects, display: none or visible: hidden)

I came up with tiny jQuery plugin to detect autoplay. See if it is more reliable:

(function ($) {
   $.extend({
      'canVideoautoplay' : function ( callback ) {

         var testStarted = false;
         try {

            var playsinline = navigator.userAgent.match(/(iPhone|iPod)/g) ? ('playsInline' in document.createElement('video')) : true;
            if (!playsinline) {
               return callback(false);
            }

            var src = 'data:video/mp4;base64,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';
            var $video = $('<video src="'+src+'" controls playsinline muted width="20" height="20" style="position:fixed;z-index:1000;top:0;left:0"></video>');
            $('body').prepend($video);

            testStarted = true;
            $video[0].play();

            $video[0].onplay = function() {
               this.playing = true;
            };

            $video[0].oncanplay = function() {
               if ($video[0].playing) {
                  callback(true);
               } else {
                  callback(false);
               }
               $video[0].pause();
               $video.remove();
            };
         } catch(e) {}

         if (!testStarted) {
            callback(false);
         }
      }
   });
})(jQuery);

You can use it like this:

$(function () {
   $.canVideoautoplay(function ( canAutoplay ) {
      alert('Can we autoplay? ' + canAutoplay);
   });
});

回答6:

I realize this is a video question - and it applies to audio too.

I have built an audio test with the intention of loading it into Moderizr with Modernizr.addTest().

The results are surprising and very dependent on platform and system state. Turns out there are several Android browsers that support autoplay. Who knew.

From looking at GitHub, I imagine the Modernizr guys will figure all this out more reliably and elegantly than I have - if they haven't already. It seems to boil down to timing. You'd think the browsers guys would throw us a bone here. Maybe they will.

Anyway, here is the jsfiddle link: Audio().autoplay test.

While there is fluff code in the jsfiddle example, here's the core:

var supportsAutoplay = false; //assume
var audio = new Audio();
var waitTime;
audio.autoplay = true;
audio.volume = 0;

// this will only be triggered if autoplay works
audio.addEventListener('play', function () {
    supportsAutoplay = true;
});

audio.src = testSrc; //see if the listener is listening

setTimeout(          //wait for listener to run
    function(){
        return supportsAutoplay;
    },
    waitTime
);

While I have not seen one with a setTimeout other than the one above (the Modernizr guys talk about it), there are several versions of this code around. I guess I'll credit Peter Coles. Maybe his version is less likely to suffer from timing issues.

回答7:

Modernizr autoplay test has some reliability issues, as pointed here: https://github.com/Modernizr/Modernizr/issues/1095

You can detect video autoplay support by checking if the paused status of a video element changes after it programmatically plays. This alone can return false negatives in some mobile browsers, so a Promise check should be added in order to cover these.

This method works in all major browsers (desktop and mobile), except for Android <= 4.0 and Windows Phone, where it returns a false negative.

Here is the detect function:

var supports_video_autoplay = function(callback) {

  if (typeof callback !== "function") return false;

  var v = document.createElement("video");
  v.paused = true;
  var p = "play" in v && v.play();

  callback(!v.paused || ("Promise" in window && p instanceof Promise));

};

Usage:

supports_video_autoplay(function(supported) {
  if (supported) {
    // video autoplay supported!
  } else {
    // no video autoplay support :(
  }
});

Live test: https://codepen.io/paulorely/pen/QveEGy

回答8:

Maybe I respond a little bit late but I just test a solution which work fine for me :

var loadStarted = false;

video.onloadstart = function(){
    loadStarted = true;
};

function checkRunning(){
    if(!loadStarted) removeVideo();
}

setTimeout(checkRunning, 1000);

The setTimeout is not very clean, but the overall solution is super simple like that !

回答9:

Maybe you find it useful. I combined all the comments suggested in this thread into this solution: https://github.com/kaufguy/autoplay-detector

Demo here: https://kaufguy.github.io/autoplay-detector/

I also restricted it to inline play only.

var MUTE_DELAY_PORTION = 25;

var isAutoplaySupported = function (callback, timeout) {
    var called = false;
    if (!callback) {
        return;
    }
    if (!isPlaysinline()) {
        return callback({ autoplay: false, muted: false });
    }
    checkAutoplay(false, function () { testHandler(false); });
    setTimeout(function () {
        checkAutoplay(true, function () { testHandler(true); });
    }, timeout / MUTE_DELAY_PORTION);
    var testHandler = function (mute) {
        if (!called) {
            called = true;
            callback({ autoplay: true, muted: mute });
        }
    };
    setTimeout(function () {
        if (!called) {
            called = true;
            callback({ autoplay: false, muted: false });
        }
    }, timeout);
};

var checkAutoplay = function (mute, callback) {
    var video = document.createElement('video');
    video.ontimeupdate = function () {
        if (video.currentTime != 0) {
            return callback();
        }
        ;
    };
    video.autoplay = true;
    video.muted = mute;
    video.setAttribute('webkit-playsinline', 'webkit-playsinline');
    video.setAttribute('playsinline', 'playsinline');
    video.src = 'data:audio/mpeg;base64,/+MYxAAAAANIAUAAAASEEB/jwOFM/0MM/90b/+RhST//w4NFwOjf///PZu////9lns5GFDv//l9GlUIEEIAAAgIg8Ir/JGq3/+MYxDsLIj5QMYcoAP0dv9HIjUcH//yYSg+CIbkGP//8w0bLVjUP///3Z0x5QCAv/yLjwtGKTEFNRTMuOTeqqqqqqqqqqqqq/+MYxEkNmdJkUYc4AKqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq';
    video.style.display = 'none';
    video.load();
    video.play();
    return video;
};

var isPlaysinline = function () {
    return navigator.userAgent.match(/(iPhone|iPod)/g) ? ('playsInline' in document.createElement('video')) : true;
};

isAutoplaySupported(function(autoplayResult){
    //do somthing
}, 400)

Works for me...