ogv.js Lets iPhone Decode and Play WebM Videos

An educational, self-contained demo based on the article: JavaScript decoding, canvas playback, native video comparison, WebAssembly fallback, and the need to build player controls manually.

1. Insert a container and mount an OGV-style player

Code:
<div id="player">
Result:
Source Waiting for player
Rendering target Canvas, not native video chrome
Debug Enabled

2. Canvas playback avoids manufacturer video overlays

Code:
<div class="player-shell">
  <canvas id="canvasDecode" width="667" height="375"></canvas>
  <div class="comment-layer">
    <span class="bullet">Bullet comments stay visible</span>
    <span class="bullet">No forced fullscreen button</span>
    <span class="bullet">Canvas is just normal page content</span>
  </div>
</div>

<button id="canvasToggle">Pause</button>
Result:
Bullet comments stay visible No forced fullscreen button Canvas is just normal page content
Article problem Some Android browsers add native floating buttons over video.
ogv.js idea Decode frames in JavaScript and paint them into canvas.

3. Native video can have a different compatibility result

Code:
<div class="player-shell">
  <div class="video-sim">
    <strong>Native &lt;video&gt; WebM test</strong>
    <span id="nativeMessage">Choose a device profile.</span>
  </div>
  <div class="native-overlay">
    <span class="native-badge">DL</span>
    <span class="native-badge">FULL</span>
  </div>
</div>

<select id="deviceProfile">
  <option value="iphone">iPhone Safari / WeChat</option>
  <option value="newAndroid">New Android browser</option>
  <option value="oldAndroid">Older Android browser</option>
</select>
Result:
Native <video> WebM test
Choose a device profile.
DL FULL
Native result Waiting
Canvas decoder result Waiting

4. Fall back when WebAssembly is unavailable

Code:
function choosePlaybackMode(hasWebAssembly) {
  if (hasWebAssembly) {
    return {
      mode: 'ogv.js canvas decoder',
      detail: 'Use JavaScript/WebAssembly decoding for WebM.'
    };
  }

  return {
    mode: 'native <video> fallback',
    detail: 'Avoid the decoder and let the browser try normal playback.'
  };
}

var support = document.getElementById('wasmSupport');
var output = document.getElementById('fallbackOutput');

support.addEventListener('change', function () {
  var result = choosePlaybackMode(support.checked);
  output.innerHTML = '<strong>' + result.mode + '</strong><br>' + result.detail;
});
Result:

The article suggests falling back to the native video element when the device cannot support the decoder path.

5. Build the player controls yourself

Code:
<div class="manual-player">
  <div class="player-shell">
    <canvas id="manualCanvas" width="667" height="375"></canvas>
  </div>

  <div class="control-bar">
    <button id="manualPlay" class="primary">Play</button>
    <button id="manualPause">Pause</button>
    <div class="timeline">
      <span class="time-text" id="currentTime">0:00</span>
      <input id="seekBar" type="range" min="0" max="100" value="0">
      <span class="time-text">0:20</span>
    </div>
  </div>
</div>
Result:
0:00 0:20

6. Compare the format tradeoff

Code:
var formatSelect = document.getElementById('formatSelect');
var formatOutput = document.getElementById('formatOutput');

var formatNotes = {
  webm: 'WebM is open and royalty-free. With ogv.js, it can become playable on iPhone through canvas decoding.',
  mp4: 'MP4 has the broadest practical support, so it is still the simplest default choice for many products.',
  hevc: 'HEVC/H.265 can be very compact, but browser support is uneven and often Safari-centered.'
};

formatSelect.addEventListener('change', function () {
  formatOutput.innerHTML = '<strong>' + formatSelect.value.toUpperCase() + '</strong><br>' + formatNotes[formatSelect.value];
});
Result: