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Highlight player seekbar in HTML5 video

由 社会主义新天地 提交于 2020-03-20 05:58:05

问题


I have a customized seekbar for my HTML5 video player. But I need to highlight some predefined portions of the seekbar, say seconds 2-5 and 7-8. How can I do that?

Basically, I need it to be something like this:

Here is my simple code so far:

<!DOCTYPE html> 
<html> 
<head>

<style>
.body{
background-color:black;
}
.video-player {
  position: relative;
  width: 66%;
  height: 66%;
}
.video-player img {
  width: 100%;
  height: 100%;
}
.video-player video {
  position: fixed;
  top: 0;
  left: 0;
  min-width: 66%;
  min-height: 66%;
  width: auto;
  height: auto;
  z-index: -100;
  background-repeat: no-repeat;
}
.video-player .controls {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
}
.video-player .controls .progress-bar {
  position: absolute;
  margin-left: 28%;
  bottom: 10%;
  color: orange;
  font-size: 12px;
  width: 40%;
  height: 8%;
  border: none;
  background: #434343;
  border-radius: 9px;
  vertical-align: middle;
  cursor: pointer;
}
.video-player .controls progress::-moz-progress-bar {
  color: orange;
  background: #434343;
}
.video-player .controls progress[value]::-webkit-progress-bar {
  background-color: #434343;
  border-radius: 2px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.25) inset;
}
.video-player .controls progress[value]::-webkit-progress-value {
  background-color: orange;
}

video#backgroundvid {
  position: absolute;
  right: 0;
  bottom: 0;
  min-width: 100%;
  min-height: 100%;
  width: auto;
  height: auto;
  z-index: -100;
  background-repeat: no-repeat;

}
</style>
</head>

<body>
<div class="video-player">
  <video preload="auto" autoplay loop id="backgroundvid">
    <source src="mov_bbb.mp4" type="video/mp4">
    Your browser does not support HTML5 video.
  </video>
  <img src="top2.png" style="object-fit:cover" alt="" id="backgroundvid">
  <div class="controls">
    <progress class="progress-bar" style="object-fit:cover; z-index=10000" min="0" max="100" value="0">0% played</progress>
  </div>
</div>

<script>
const player = document.querySelector('.video-player');
const video = player.querySelector('video');
const progressBar = player.querySelector('.progress-bar');

video.addEventListener('timeupdate', updateProgressBar, false);
progressBar.addEventListener('click', seek);

function updateProgressBar() {
  var percentage = Math.floor((100 / video.duration) * video.currentTime);
  progressBar.value = percentage;
  progressBar.innerHTML = percentage + '% played';
}

function seek(e) {
  let percent = e.offsetX / this.offsetWidth;
  video.currentTime = percent * video.duration;
  e.target.value = Math.floor(percent / 100);
  e.target.innerHTML = progressBar.value + '% played';
}
</script>
</body> 
</html>

回答1:


You can use a canvas that you will superimpose on top of your progress-bar,

Then you will have just to draw the markers in this canvas.

Just making slight changes in the html (adding an id to the progress-bar id="progress-bar"):

<progress id="progress-bar" class="progress-bar" style="object-fit:cover; z-index=10000" min="0" max="100" value="0">0% played</progress>

Adding the CSS to style place the canvas (same CSS property than your progress-bar)

#markers{
    position: absolute;
    bottom: 10%;
    margin-left: 28%;
    border-radius: 9px;
    pointer-events: none;
}

Note the pointer-events: none; If you don't put it, you can't have access to the control of your progress-bar.

And so, the javascript to create & insert the canvas, and then place the markers on it.

// We need the metadata 'duration', so we wrap the code in an event listener to be sure we execute our code when the metadata is loaded
video.addEventListener('loadedmetadata', function () {
    // Get the dimension of the progress-bar
    const progressbar = document.getElementById('progress-bar');
    const widthProgressBar = window.getComputedStyle(progressbar, null).getPropertyValue("width");
    const heightProgressBar = window.getComputedStyle(progressbar, null).getPropertyValue("height");
    // Create the canvas
    const canvas = document.createElement('canvas');
    const w = canvas.width = parseFloat(widthProgressBar);
    const h = canvas.height = parseFloat(heightProgressBar);
    canvas.id = 'markers';
    const progressBar = document.getElementById("progress-bar");
    // Insert the canvas in the DOM
    progressBar.parentNode.insertBefore(canvas, progressBar.nextSibling)
    // Define the context
    const ctx = canvas.getContext('2d');
    // Calcul how many px will represent 1s
    const videoDuration = video.duration;
    const ratioPxBySeconds = parseFloat(w) / videoDuration;
    // Define the markers
    const markers = {
        'marker1': [2, 5],
        'marker2': [7, 8]
    };

    // Function to draw the markers
    function setMarkers(markers, ratioPxSec, height) {
        for (marker in markers) {
            let x = markers[marker][0] * ratioPxSec; // Start x position of the marker
            let y = 0; // Start y position of the marker
            let w = (markers[marker][1] - markers[marker][0]) * ratioPxSec; // Width of the marker
            let h = parseFloat(height); // Height of the marker
            ctx.fillStyle = "#7f3302"; // Set the color of the marker
            ctx.fillRect(x, y, w, h); // Draw a rectangle
        }
    }

    setMarkers(markers, ratioPxBySeconds, h); // Call the function
});


const player = document.querySelector('.video-player');
const video = player.querySelector('video');
const progressBar = player.querySelector('.progress-bar');

video.addEventListener('timeupdate', updateProgressBar, false);
progressBar.addEventListener('click', seek);

function updateProgressBar() {
  var percentage = Math.floor((100 / video.duration) * video.currentTime);
  progressBar.value = percentage;
  progressBar.innerHTML = percentage + '% played';
}

function seek(e) {
  let percent = e.offsetX / this.offsetWidth;
  video.currentTime = percent * video.duration;
  e.target.value = Math.floor(percent / 100);
  e.target.innerHTML = progressBar.value + '% played';
}

// We need the metadata 'duration', so we wrap the code in an event listener to be sure we execute our code when the metadata is loaded
video.addEventListener('loadedmetadata', function() {
  // Get the dimension of the progress-bar
  const progressbar = document.getElementById('progress-bar');
  const widthProgressBar = window.getComputedStyle(progressbar, null).getPropertyValue("width");
  const heightProgressBar = window.getComputedStyle(progressbar, null).getPropertyValue("height");
  // Create the canvas
  const canvas = document.createElement('canvas');
  const w = canvas.width = parseFloat(widthProgressBar);
  const h = canvas.height = parseFloat(heightProgressBar);
  canvas.id = 'markers';
  const progressBar = document.getElementById("progress-bar");
  // Insert the canvas in the DOM
  progressBar.parentNode.insertBefore(canvas, progressBar.nextSibling)
  // Define the context
  const ctx = canvas.getContext('2d');
  // Calcul how many px will represent 1s
  const videoDuration = video.duration;
  const ratioPxBySeconds = parseFloat(w) / videoDuration;
  // Define the markers
  const markers = {
    'marker1': [2, 5],
    'marker2': [7, 8]
  };

  // Function to draw the markers
  function setMarkers(markers, ratioPxSec, height) {
    for (marker in markers) {
      let x = markers[marker][0] * ratioPxSec; // Start x position of the marker
      let y = 0; // Start y position of the marker
      let w = (markers[marker][1] - markers[marker][0]) * ratioPxSec; // Width of the marker
      let h = parseFloat(height); // Height of the marker
      ctx.fillStyle = "rgb(127, 51, 2, 0.9)"; // Set the color of the marker
      ctx.fillRect(x, y, w, h); // Draw a rectangle
    }
  }

  setMarkers(markers, ratioPxBySeconds, h); // Call the function
  
  // Calculate the new dimensions & redraw
  function resize(){
    const progressBar = document.getElementById('progress-bar');
    const w = canvas.width = progressBar.clientWidth;
    const h = canvas.height = progressBar.clientHeight;
    const ratioPxBySeconds = parseFloat(w) / videoDuration;
    setMarkers(markers, ratioPxBySeconds, h);
  }
  // On page resize, call the resize() function
  window.addEventListener("resize", resize, false);
  
});
body {
  background-color: black;
}

.video-player {
  position: relative;
  width: 66%;
  height: 66%;
}

.video-player img {
  width: 100%;
  height: 100%;
}

.video-player video {
  position: fixed;
  top: 0;
  left: 0;
  min-width: 66%;
  min-height: 66%;
  width: auto;
  height: auto;
  z-index: -100;
  background-repeat: no-repeat;
}

.video-player .controls {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
}

.video-player .controls .progress-bar {
  position: absolute;
  margin-left: 28%;
  bottom: 10%;
  color: orange;
  font-size: 12px;
  width: 40%;
  height: 8%;
  border: none;
  background: #434343;
  border-radius: 9px;
  vertical-align: middle;
  cursor: pointer;
}

#markers {
  position: absolute;
  bottom: 10%;
  margin-left: 28%;
  border-radius: 9px;
  pointer-events: none;
}

.video-player .controls progress::-moz-progress-bar {
  color: orange;
  background: #434343;
}

.video-player .controls progress[value]::-webkit-progress-bar {
  background-color: #434343;
  border-radius: 2px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.25) inset;
}

.video-player .controls progress[value]::-webkit-progress-value {
  background-color: orange;
}

video#backgroundvid {
  position: absolute;
  right: 0;
  bottom: 0;
  min-width: 100%;
  min-height: 100%;
  width: auto;
  height: auto;
  z-index: -100;
  background-repeat: no-repeat;
}
<div class="video-player">
  <video preload="auto" autoplay loop id="backgroundvid">
    <source src="https://www.w3schools.com/html/mov_bbb.mp4" type="video/mp4">
    Your browser does not support HTML5 video.
  </video>
  <img src="https://i.stack.imgur.com/gmK7P.png" style="object-fit:cover" alt="" id="backgroundvid">
  <div class="controls">
    <progress id="progress-bar" class="progress-bar" style="object-fit:cover; z-index=10000" min="0" max="100" value="0">0% played</progress>
  </div>
</div>

Edit:

Added a resize() function to update the markers when the screen resize

(typically, it will happen when you put the video in full screen)

// Calculate the new dimensions & redraw
function resize(){
  const progressBar = document.getElementById('progress-bar');
  const w = canvas.width = progressBar.clientWidth;
  const h = canvas.height = progressBar.clientHeight;
  const ratioPxBySeconds = parseFloat(w) / videoDuration;
  setMarkers(markers, ratioPxBySeconds, h);
}
// On page resize, call the resize() function
window.addEventListener("resize", resize, false);


来源：https://stackoverflow.com/questions/60732196/highlight-player-seekbar-in-html5-video

标签
javascript
html
css
html5-video
video-player
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