preload: none html code example
Example: html video preload
const video = document.querySelector('video');
const mediaSource = new MediaSource();
video.src = URL.createObjectURL(mediaSource);
mediaSource.addEventListener('sourceopen', function() {
URL.revokeObjectURL(video.src);
mediaSource.addSourceBuffer('video/webm; codecs="vp9"');
log('Fetching video init segment...');
fetchAndAppendSegment('bytes=0-299');
}, { once: true });
function onSetInfiniteDurationButtonClick() {
log('User clicked "mediaSource.duration = +Infinity" button');
// Makes video behave like a live stream.
mediaSource.duration = +Infinity;
logMediaInfo();
}
function onFetchAndAppend3To6MediaButtonClick() {
log('Fetching video segment that starts at 3 seconds...');
fetchAndAppendSegment('bytes=567140-1196488');
}
function onSetLiveSeekableRangeButtonClick(event) {
const re = /mediaSource\.setLiveSeekableRange\((\d+), (\d+)\)/;
const start = Number(re.exec(event.target.textContent)[1]);
const end = Number(re.exec(event.target.textContent)[2]);
log(`User clicked "mediaSource.setLiveSeekableRange(${start}, ${end})" button`);
mediaSource.setLiveSeekableRange(start, end);
logMediaInfo();
}
function onClearLiveSeekableRangeButtonClick() {
log('User clicked "mediaSource.clearLiveSeekableRange()" button');
mediaSource.clearLiveSeekableRange();
logMediaInfo();
}
function onRemoveMediaSegmentButtonClick() {
const sourceBuffer = mediaSource.sourceBuffers[0];
log('User clicked "sourceBuffer.remove(3, 6)" button');
sourceBuffer.remove(3 /* start */, 6 /* end*/);
sourceBuffer.addEventListener('updateend', function() {
logMediaInfo();
}, { once: true });
}
function onSetFiniteDurationButtonClick() {
log('User clicked "mediaSource.duration = 6" button');
mediaSource.duration = 6;
logMediaInfo();
}
function onEndOfStreamButtonClick() {
log('User clicked "mediaSource.endOfStream()" button');
mediaSource.endOfStream();
mediaSource.addEventListener('sourceended', function() {
logMediaInfo();
}, { once: true });
}
/* Utils */
function fetchAndAppendSegment(range) {
const videoUrl = 'https://storage.googleapis.com/media-session/sample.webm';
const sourceBuffer = mediaSource.sourceBuffers[0];
fetch(videoUrl, { headers: { range } })
.then(response => response.arrayBuffer())
.then(data => {
sourceBuffer.appendBuffer(data);
sourceBuffer.addEventListener('updateend', function() {
logMediaInfo();
}, { once: true });
});
}
function logMediaInfo() {
log(`> Seekable time ranges: ${timeRangesToString(video.seekable)}`);
log(`> Buffered time ranges: ${timeRangesToString(video.buffered)}`);
log(`> MediaSource duration: ${mediaSource.duration}`);
log('');
}
function timeRangesToString(ranges) {
var s = "{";
for (var i = 0; i < ranges.length; ++i) {
s += " [" + ranges.start(i).toFixed(3) + ", " + ranges.end(i).toFixed(3) + ")";
}
return s + " }";
}