如何在HTML5视频上设置缩略图?

Ivi*_*pić 97 html html5 preloading html5-video

有没有办法在HTML5视频上设置缩略图?我想在比赛前看一些照片.我的代码看起来像这样:

<video width="470" height="255" controls>
    <source src="video.mp4" type="video/mp4">
    <source src="video.ogg" type="video/ogg">
    <source src="video.webm" type="video/webm">
    <object data="video.mp4" width="470" height="255">
    <embed src="video.swf" width="470" height="255">
    </object>
</video>
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谢谢!

Jas*_*oks 170

添加poster="placeholder.png"到视频标记.

<video width="470" height="255" poster="placeholder.png" controls>
    <source src="video.mp4" type="video/mp4">
    <source src="video.ogg" type="video/ogg">
    <source src="video.webm" type="video/webm">
    <object data="video.mp4" width="470" height="255">
    <embed src="video.swf" width="470" height="255">
    </object>
</video>
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那样有用吗?

  • 有关更多信息,请参阅 MDN 网站:https://developer.mozilla.org/en-US/docs/Web/HTML/Element/video。该属性得到了很好的支持。 (4认同)
  • 仅供参考,“海报”与嵌入视频文件中的视频缩略图不同。是的,这就是语义,对于大多数人来说,他们会想到 html 中的“缩略图”,这实际上是 HTML5 海报属性,并且不存在于视频文件中。要解决视频拇指问题,您需要执行以下有关设置起始帧的答案。 (3认同)

Dav*_*han 69

将您的视频第一帧显示为缩略图:

添加 preload="metadata"到您的视频标签和第一帧的第二#t=0.5到您的视频来源:

<video width="400" controls="controls" preload="metadata">
  <source src="https://www.w3schools.com/html/mov_bbb.mp4#t=0.5" type="video/mp4">
</video>
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  • 问题是视频从指定的#t = 0.5开始。假设如果您想从t = 8开始缩略图,那么vid将从8秒开始,这不是很理想:) (4认同)

PVC*_*VCS 16

如果您想将视频第一帧作为缩略图,则可以使用

Add #t=0.1 to your video source, like below

<video width="320" height="240" controls>
  <source src="video.mp4#t=0.1" type="video/mp4">
</video>
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注意:确保您的视频类型(例如:mp4,ogg,webm等)

  • 仅在视频已预加载时.否则,在浏览器加载视频之前,它仍会在IE上显示黑色背景! (4认同)
  • 0.1s 究竟如何是第一帧? (2认同)

Ivi*_*pić 5

我找到了我从你的例子和其他例子中得到的解决方案,并做了这个:

<video id="video1" width="470" height="264"  poster="video_poster.jpg" onclick="playPause()">
                  <source src="video.mp4" width="470" height="264" type="video/mp4" >
                  <source src="video.webm" type="video/webm" >
                  <source src="video.ogv" type="video/ogg" >                      
                  <object id="FlashID" classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" width="470" height="264" >
                  <param name="movie" value="video.swf" >
                  <param name="quality" value="high">
                  <param name="wmode" value="opaque">
                  <param name="swfversion" value="11.0.0.0">
                  <!-- This param tag prompts users with Flash Player 6.0 r65 and higher to download the latest version of Flash Player. Delete it if you don’t want users to see the prompt. -->
                  <param name="expressinstall" value="../../Scripts/expressInstall.swf">
                  <!-- Next object tag is for non-IE browsers. So hide it from IE using IECC. -->
                  <!--[if !IE]>-->
                  <object type="application/x-shockwave-flash" data="video.swf" width="500" height="500">
                    <!--<![endif]-->
                    <param name="quality" value="high">
                    <param name="wmode" value="opaque">
                    <param name="swfversion" value="11.0.0.0">
                    <param name="expressinstall" value="../../Scripts/expressInstall.swf">
                    <!-- The browser displays the following alternative content for users with Flash Player 6.0 and older. -->
                    <div>
                      <h4>Content on this page requires a newer version of Adobe Flash Player.</h4>
                      <p><a href="http://www.adobe.com/go/getflashplayer"><img src="http://www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash player" width="112" height="33" /></a></p>
                    </div>
                    <!--[if !IE]>-->
                  </object>
                  <!--<![endif]-->
                    Unfortunately Your browser is old and does not support full video experience.
                </object>


                </video> 
                <script> 
                var myVideo=document.getElementById("video1"); 
                var att=document.createAttribute("poster");
                if (myVideo.error) {
                     switch (myVideo.error.code) {
                       case MEDIA_ERR_NETWORK:alert("Network error - please try again later.");break;
                       case MEDIA_ERR_DECODE:alert("Video is broken.."); break;
                       case MEDIA_ERR_SRC_NOT_SUPPORTED:alert("Sorry, your browser can't play this video."); break;
                     }
                }
                else
                {
                    function playPause()
                    { 
                        if (myVideo.paused) 
                        {
                          myVideo.play();
                          att.value="";
                          myVideo.setAttributeNode(att);
                        }
                        else myVideo.pause();
                    }
                }                       
                </script>
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很棒的工作。谢谢!


deb*_*ish 5

<?php
$thumbs_dir = 'E:/xampp/htdocs/uploads/thumbs/';
$videos = array();
if (isset($_POST["name"])) {
 if (!preg_match('/data:([^;]*);base64,(.*)/', $_POST['data'], $matches)) {
  die("error");
 }
 $data = $matches[2];
 $data = str_replace(' ', '+', $data);
 $data = base64_decode($data);
 $file = 'text.jpg';
 $dataname = file_put_contents($thumbs_dir . $file, $data);
}
?>
//jscode
<script type="text/javascript">
 var videos = <?= json_encode($videos); ?>;
 var video = document.getElementById('video');
 video.addEventListener('canplay', function () {
     this.currentTime = this.duration / 2;
 }, false);
 var seek = true;
 video.addEventListener('seeked', function () {
    if (seek) {
         getThumb();
    }
 }, false);

 function getThumb() {
     seek = false;
     var filename = video.src;
     var w = video.videoWidth;//video.videoWidth * scaleFactor;
     var h = video.videoHeight;//video.videoHeight * scaleFactor;
     var canvas = document.createElement('canvas');
     canvas.width = w;
     canvas.height = h;
     var ctx = canvas.getContext('2d');
     ctx.drawImage(video, 0, 0, w, h);
     var data = canvas.toDataURL("image/jpg");
     var xmlhttp = new XMLHttpRequest;
     xmlhttp.onreadystatechange = function () {
         if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
         }
     }
     xmlhttp.open("POST", location.href, true);
     xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
     xmlhttp.send('name=' + encodeURIComponent(filename) + '&data=' + data);
 }
  function failed(e) {
     // video playback failed - show a message saying why
     switch (e.target.error.code) {
         case e.target.error.MEDIA_ERR_ABORTED:
             console.log('You aborted the video playback.');
             break;
         case e.target.error.MEDIA_ERR_NETWORK:
             console.log('A network error caused the video download to fail part-way.');
             break;
         case e.target.error.MEDIA_ERR_DECODE:
             console.log('The video playback was aborted due to a corruption problem or because the video used features your browser did not support.');
              break;
          case e.target.error.MEDIA_ERR_SRC_NOT_SUPPORTED:
              console.log('The video could not be loaded, either because the server or network failed or because the format is not supported.');
              break;
          default:
              console.log('An unknown error occurred.');
              break;
      }


  }
</script>
//Html
<div>
    <video   id="video" src="1499752288.mp4" autoplay="true"  onerror="failed(event)" controls="controls" preload="none"></video>
</div>
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