HTML5 video tag volume control missing

问题

The volume control in HTML5 videos on my website is not appearing, see screenshot: The video plays when started, but without any sound. The videos also play fine (with sound) in VLC and Windows Media Player.

I have tested in Chrome (65.0.3325.162), Firefox (59.0.1), and Android (on a Samsung tablet). The volume of my system is fine with other applications, and YouTube videos.

Here is the (minimal) code (adding additional attributes like height and poster etc. makes no difference to the problem):

<!DOCTYPE html>
<html lang='en'>
<body>

    <video controls src='vid1.mp4' width='500'>
    </video>

    <video controls width='500'>
        <source src='vid2.mp4' type='video/mp4' />
    </video>

</body>
</html>

Am I missing something obvious?

[1]: https://i.stack.imgur.com/qAl7D.png

EDIT:

When I tested with a sample video on http://techslides.com/demos/sample-videos/small.mp4 the controls appeared. It seems to have something to do with the encoded mp4 video itself.

I have now removed the video urls. I re-encoded the videos using VLC, and they are now working correctly.

回答1:

Why are these HTML5 video problems cropping up now after 5+ years?

TLDR: Your code routes around video content farms and their ad-click revenue by short circuiting MP4 content and eyeballs per second, this is retaliation. It's par for the course.

Browser developers have busted your HTML5 <video> browser embed code, either on purpose or by accident around the codecs needed to decode them. They own the source code of the browser that interprets and decodes your HTML5 MP4 file for presentation in the browser content area. Chrome developers corner the market on MP4 Videos and had their arms twisted by the powers that be. So the browser sees that the codec required to decode your MP4 is likely from an unauthorized area, and thus here we are scratching our heads as to why chrome isn't showing a volume button.

My requirements has to be that HTML5 Video is fixed on server side, I can't require users to fiddle around with their chrome flags or installing a plugin that corrects the bug. It has to just work by default on the latest Chrome, Safari, Firefox then IE, preferably in that order.

Screenshot of the case of the missing HTML5 video volume button:

The video plays, but at zero volume. No volume button is ever presented either during initial load, nor during or after playback. The mp4 download and go-full screen buttons are presented and work correctly during playback.

And yes, the chrome flags for new media player are disabled:

What it looked like before, what I expect to see:

The stripped down code I'm using:

This code was evolved from the likes of: http://camendesign.com/code/video_for_everybody

<html><body>
<video width="640" 
       preload="none" 
       height="360" 
       poster="some_content.png" 
       controls="controls">
    <source src="some_content.mp4"
    <source src="__VIDEO__.webm" type="video/webm" />
    <source src="__VIDEO__.ogv" type="video/ogg" /><!--[if gt IE 6]>
    <object width="640" height="375" classid="clsid:02BF25D5-8C17-4B23-BC80-D348
    [endif]--><!--[if !IE]><!-->
    <object width="640" height="375" type="video/quicktime" data="__VIDEO__.mp4"
    <param name="src" value="__VIDEO__.mp4" />
    <param name="autoplay" value="false" />
    <param name="showlogo" value="false" />
    <object width="640" height="380" type="application/x-shockwave-flash"
        data="__FLASH__.swf?image=__POSTER__.jpg&amp;file=__VIDEO__.mp4"> 
        <param name="movie" value="__FLASH__.swf?image=__POSTER__.jpg&amp;file=_
        <img src="__POSTER__.jpg" width="640" height="360" />
        <p>
            <strong>No video playback capabilities detected.</strong>
            Why not try to download the file instead?<br>
            <a href="__VIDEO__.mp4">MPEG4</a>
            <a href="__VIDEO__.ogv">Ogg Theora</a>
        </p> 
    </object><!--[if gt IE 6]><!-->
    </object><!--<![endif]-->
</video>
</body></html>

The above code is the code that used to work, but got broken.

Final solution that worked for me: Manual clean of the 3rd party taint from my MP4 videos.

There are many options to clean and re-encode an MP4 video, some free others non-free. One way is open the MP4 file with VLC or other video player or software that has and open/save/reencode/convert tools in it, and save it out to a different video encoding format.

I was able to cook up a handy dandy script in Java to iterate over every MP4 file crack open the MP4 file, clean out the hobo taint if it exists then save and redeploy the mp4 file, and now all is well. Then do this on a schedule.

Other solutions considered, but rejected:

Eliminate the bugged HTML5 video embed tag from your tool set. Display an image with an html5 <img .../> tag, overlay a play button so as to indicate this is a video, when the user clicks either open a new tab where the raw MP4 video plays in browser: the volume button is shown correctly, or worst case the user downloads the MP4 video to disk, and they can open it up from disk with their video player.
Use a different browser or an open source browser, that know how to do the right thing.
Try toggling on the 'new media controls' chrome://flags, maybe at some point in the future the Chrome Devs will push a fix and it won't freak out on the evidence that the mp4 smells of digital rights violations.
Yield the vanguard and eyeball click revenue to the big player content providers, just use an <a href="">whatever</a> tag to redirect users to the websites who are able to show video correctly.

The game is afoot make your time.

回答2:

It seems that you are using a mute video. Because of that, the volume control is not showing.

Check this out:

<video  src='https://www.w3schools.com/tags/mov_bbb.mp4' controls>
</video>

来源：https://stackoverflow.com/questions/49357612/html5-video-tag-volume-control-missing

标签

html5

video

html5-video

volume