| <!DOCTYPE html> |
| <html> |
| <head> |
| <title> |
| mediaelementaudiosourcenode-preservespitch.html |
| </title> |
| <script src="../../imported/w3c/web-platform-tests/resources/testharness.js"></script> |
| <script src="../../resources/testharnessreport.js"></script> |
| <script src="../resources/audit-util.js"></script> |
| <script src="../resources/audit.js"></script> |
| </head> |
| <body> |
| <script id="layout-test-code"> |
| let audit = Audit.createTaskRunner(); |
| |
| function waitFor(element, type) { |
| return new Promise(resolve => { |
| element.addEventListener(type, resolve, { once: true }); |
| }); |
| } |
| |
| function sleepFor(time) { |
| return new Promise(resolve => setTimeout(resolve, time)); |
| } |
| |
| audit.define( |
| { |
| label: 'mediaelementsourcenode-volume', |
| description: 'Verify volume changes to the media element are audible when attached to a MediaElementSourceNode' |
| }, |
| async (task, should) => { |
| window.audioElement = new Audio('../resources/media/sine440.mp3'); |
| waitFor(audioElement, 'error').then(event => { |
| throw new Error(`Audio element fired "${event.type}" with error code: ${event.target.error.code}, "${event.target.error.message}"`); |
| }); |
| |
| let context = new AudioContext({sampleRate: 48000}); |
| let mediaSource = context.createMediaElementSource(audioElement); |
| let analyser = context.createAnalyser(); |
| let gain = context.createGain(); |
| |
| analyser.fftSize = 2048; |
| analyser.smoothingTimeConstant = 0; |
| analyser.minDecibels = -40; |
| analyser.maxDecibels = 0; |
| let frequencyData = new Uint8Array(analyser.frequencyBinCount); |
| |
| // Silence test output |
| gain.gain.value = 0; |
| |
| mediaSource.connect(analyser); |
| analyser.connect(gain); |
| gain.connect(context.destination); |
| |
| context.resume(); |
| audioElement.play(); |
| |
| let getDecibels = async function(frequency) { |
| let attempts = 0; |
| while (audioElement.currentTime < 0.5) { |
| if (++attempts >= 20) |
| throw new Error(`audioElement.currentTime stuck at ${audioElement.currentTime} after ${attempts} attempts`); |
| await sleepFor(100); |
| } |
| analyser.getByteFrequencyData(frequencyData); |
| const binIndex = Math.round(frequency * analyser.fftSize / context.sampleRate); |
| return frequencyData[binIndex]; |
| } |
| |
| let fullVolumeDecibels = await getDecibels(440); |
| should(fullVolumeDecibels > 0, 'fullVolumeDecibels > 0').beTrue(); |
| |
| audioElement.load(); |
| audioElement.volume = 0.5; |
| audioElement.play(); |
| |
| let halfVolumeDecibels = await getDecibels(440); |
| should(halfVolumeDecibels > 0, 'halfVolumeDecibels > 0').beTrue(); |
| should(halfVolumeDecibels < fullVolumeDecibels, 'halfVolumeDecibels < fullVolumeDecibels').beTrue(); |
| |
| audioElement.pause(); |
| context.suspend(); |
| task.done(); |
| }); |
| audit.run(); |
| </script> |
| </body> |
| </html> |
