Autoplay audio files on an iPad with HTML5

2019-01-01 14:43发布

I'm trying to get an audio file to autoplay in Safari on an iPad. If I go to the page using Safari on my Mac, it's fine. On the iPad, autoplay does not work.

15条回答
谁念西风独自凉
2楼-- · 2019-01-01 15:10

Apple does not support the standard completely, but there is a workaround. Their justification is cellular network congestion, maybe because you'll land on pages that play random audio. This behavior doesn't change when a device goes on wifi, maybe for consistency. By the way, those pages are usually a bad idea anyway. You should not be trying to put a soundtrack on every web page. That's just wrong. :)

html5 audio will play if it is started as the result of a user action. Loading a page does not count. So you need to restructure your web app to be an all-in-one-page app. Instead of a link that opens a page that plays audio, you need that link to play it on the current page, without a page change. This "user interaction" rule applies to the html5 methods you can call on an audio or video element. The calls return without any effect if they are fired automatically on page load, but they work when called from event handlers.

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看淡一切
3楼-- · 2019-01-01 15:11

Apple annoyingly rejects many HTML5 web standards on their iOS devices, for a variety of business reasons. Ultimately, you can't pre-load or auto-play sound files before a touch event, it only plays one sound at a time, and it doesn't support Ogg/Vorbis. However, I did find one nifty workaround to let you have a little more control over the audio.

<audio id="soundHandle" style="display:none;"></audio>

<script type="text/javascript">

var soundHandle = document.getElementById('soundHandle');

$(document).ready(function() {
    addEventListener('touchstart', function (e) {
        soundHandle.src = 'audio.mp3';
        soundHandle.loop = true;
        soundHandle.play();
        soundHandle.pause();
    });
});

</script>

Basically, you start playing the audio file on the very first touch event, then you pause it immediately. Now, you can use the soundHandle.play() and soundHandle.pause() commands throughout your Javascript and control the audio without touch events. If you can time it perfectly, just have the pause come in right after the sound is over. Then next time you play it again, it will loop back to the beginning. This won't resolve all the mess Apple has made here, but it's one solution.

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皆成旧梦
4楼-- · 2019-01-01 15:12

Works with jQuery, tested on Ipad v.5.1.1

$('video').get(0).play();

You have to append/remove the video element from the page.

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步步皆殇っ
5楼-- · 2019-01-01 15:20

UPDATE: This is a hack and it's not working anymore on IOS 4.X and above. This one worked on IOS 3.2.X.

It's not true. Apple doesn't want to autoplay video and audio on IPad because of the high amout of traffic you can use on mobile networks. I wouldn't use autoplay for online content. For Offline HTML sites it's a great feature and thats what I've used it for.

Here is a "javascript fake click" solution: http://www.roblaplaca.com/examples/html5AutoPlay/

Copy & Pasted Code from the site:

<script type="text/javascript"> 
        function fakeClick(fn) {
            var $a = $('<a href="#" id="fakeClick"></a>');
                $a.bind("click", function(e) {
                    e.preventDefault();
                    fn();
                });

            $("body").append($a);

            var evt, 
                el = $("#fakeClick").get(0);

            if (document.createEvent) {
                evt = document.createEvent("MouseEvents");
                if (evt.initMouseEvent) {
                    evt.initMouseEvent("click", true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
                    el.dispatchEvent(evt);
                }
            }

            $(el).remove();
        }

        $(function() {
            var video = $("#someVideo").get(0);

            fakeClick(function() {
                video.play();
            });
        });

        </script> 

This is not my source. I've found this some time ago and tested the code on an IPad and IPhone with IOS 3.2.X.

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无与为乐者.
6楼-- · 2019-01-01 15:20

If you create an Audio element using:

var a = new Audio("my_audio_file.wav");

And add a suspend event listener via:

a.addEventListener("suspend", function () {console.log('suspended')}, false);

And then load the file into mobile Safari (iPad or iPhone), you'll see the 'suspended' get logged in the developer console. According to the HTML5 spec, this means, "The user agent is intentionally not currently fetching media data, but does not have the entire media resource downloaded."

Calling a subsequent a.load(), testing for the "canplay" event and then using a.play() seems like a suitable method for auto triggering the sound.

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心情的温度
7楼-- · 2019-01-01 15:24

It seems to me that the answer to this question is (at least now) clearly documented on the Safari HTML5 docs:

User Control of Downloads Over Cellular Networks

In Safari on iOS (for all devices, including iPad), where the user may be on a cellular network and be charged per data unit, preload and autoplay are disabled. No data is loaded until the user initiates it. This means the JavaScript play() and load() methods are also inactive until the user initiates playback, unless the play() or load() method is triggered by user action. In other words, a user-initiated Play button works, but an onLoad="play()" event does not.

This plays the movie: <input type="button" value="Play" onClick="document.myMovie.play()">

This does nothing on iOS: <body onLoad="document.myMovie.play()">

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