HTML5test.com смог предсказать поддержку HLS точно как Да или Нет. Как это работает?
В исходном коде на связанной странице смотрите engine.jsстроки, 2405-2533где HTMLMediaElement.canPlayType()используется
/* video element */
function (results) {
var element = document.createElement('video');
results.addItem({
key: 'video.element',
passed: !!element.canPlayType
});
/* audioTracks property */
results.addItem({
key: 'video.audiotracks',
passed: 'audioTracks' in element
});
/* videoTracks property */
results.addItem({
key: 'video.videotracks',
passed: 'videoTracks' in element
});
/* subtitles */
results.addItem({
key: 'video.subtitle',
passed: 'track' in document.createElement('track')
});
/* poster */
results.addItem({
key: 'video.poster',
passed: 'poster' in element
});
},
/* video codecs */
function (results) {
var element = document.createElement('video');
/* mpeg-4 codec */
results.addItem({
key: 'video.codecs.mp4.mpeg4',
passed: !!element.canPlayType && canPlayType(element, 'video/mp4; codecs="mp4v.20.8"')
});
/* h.264 codec */
/* I added a workaround for IE9, which only detects H.264 if you also provide an audio codec. Bug filed @ connect.microsoft.com */
results.addItem({
key: 'video.codecs.mp4.h264',
passed: !!element.canPlayType && (canPlayType(element, 'video/mp4; codecs="avc1.42E01E"') || canPlayType(element, 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"'))
});
/* h.265 codec */
results.addItem({
key: 'video.codecs.mp4.h265',
passed: !!element.canPlayType && (canPlayType(element, 'video/mp4; codecs="hvc1.1.L0.0"') || canPlayType(element, 'video/mp4; codecs="hev1.1.L0.0"'))
});
/* theora codec */
results.addItem({
key: 'video.codecs.ogg.theora',
passed: !!element.canPlayType && canPlayType(element, 'video/ogg; codecs="theora"')
});
/* vp8 in webm codec */
results.addItem({
key: 'video.codecs.webm.vp8',
passed: !!element.canPlayType && canPlayType(element, 'video/webm; codecs="vp8"')
});
/* vp9 in webm codec */
results.addItem({
key: 'video.codecs.webm.vp9',
passed: !!element.canPlayType && canPlayType(element, 'video/webm; codecs="vp9"')
});
/* does codec detection work properly? */
var passed = true;
if (!!element.canPlayType) {
if (element.canPlayType('video/nonsense') == 'no') {
passed = false;
log('BUGGY: Codec detection bug in Firefox 3.5.0 - 3.5.1 and Safari 4.0.0 - 4.0.4 that answer "no" to unknown codecs instead of an empty string')
}
if (element.canPlayType('video/webm') == 'probably') {
passed = false;
log('BUGGY: Codec detection bug that Firefox 27 and earlier always says "probably" when asked about WebM, even when the codecs string is not present')
}
if (element.canPlayType('video/mp4; codecs="avc1.42E01E"') == 'maybe' && element.canPlayType('video/mp4') == 'probably') {
passed = false;
log('BUGGY: Codec detection bug in iOS 4.1 and earlier that switches "maybe" and "probably" around')
}
if (element.canPlayType('video/mp4; codecs="avc1.42E01E"') == 'maybe' && element.canPlayType('video/mp4') == 'maybe') {
passed = false;
log('BUGGY: Codec detection bug in Android where no better answer than "maybe" is given')
}
if (element.canPlayType('video/mp4; codecs="avc1.42E01E, mp4a.40.2"') == 'probably' && element.canPlayType('video/mp4; codecs="avc1.42E01E"') != 'probably') {
passed = false;
log('BUGGY: Codec detection bug in Internet Explorer 9 that requires both audio and video codec on test')
}
}
results.addItem({
key: 'video.canplaytype',
passed: element.canPlayType ? (passed ? YES : YES | BUGGY) : NO
});
},См. Также Apple HTTP Live Streaming (HLS)