Add a WPT for the concept of "acquiring the content" of an AudioBuffer.

Differential Revision: https://phabricator.services.mozilla.com/D131240 bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1741322 gecko-commit: c08ecee64457b5045641a020a3be502c20d389ac gecko-reviewers: karlt
web-platform-tests · Nov 17, 2021 · 08fb0f8 · 08fb0f8
1 parent 2662731
commit 08fb0f8
Showing 1 changed file with 85 additions and 0 deletions.
diff --git a/webaudio/the-audio-api/the-audiobuffer-interface/acquire-the-content.html b/webaudio/the-audio-api/the-audiobuffer-interface/acquire-the-content.html
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+<!doctype html>
+<meta charset="utf-8">
+<title>Test for AudioBuffer's "acquire the content" operation</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+const SAMPLERATE = 8000;
+const LENGTH = 128;
+
+var tests = {
+  "AudioBufferSourceNode setter set with non-null buffer": function(oac) {
+    var buf = oac.createBuffer(1, LENGTH, SAMPLERATE)
+    var bs = new AudioBufferSourceNode(oac);
+    var channelData = buf.getChannelData(0);
+    for (var i = 0; i < channelData.length; i++) {
+      channelData[i] = 1.0;
+    }
+    bs.buffer = buf;
+    bs.start(); // This acquires the content since buf is not null
+    for (var i = 0; i < channelData.length; i++) {
+      channelData[i] = 0.5;
+    }
+    allSamplesAtOne(buf, "reading back");
+    bs.connect(oac.destination);
+    return oac.startRendering();
+  },
+  "AudioBufferSourceNode buffer setter set with null" : (oac) => {
+    var buf = oac.createBuffer(1, LENGTH, SAMPLERATE)
+    var bs = new AudioBufferSourceNode(oac);
+    var channelData = buf.getChannelData(0);
+    for (var i = 0; i < channelData.length; i++) {
+      channelData[i] = 1.0;
+    }
+    bs.buffer = null;
+    bs.start(); // This does not acquire the content
+    bs.buffer = buf; // This does
+    for (var i = 0; i < channelData.length; i++) {
+      channelData[i] = 0.5;
+    }
+    allSamplesAtOne(buf, "reading back");
+    bs.connect(oac.destination);
+    return oac.startRendering();
+  },
+  "ConvolverNode": (oac) => {
+    var buf = oac.createBuffer(1, LENGTH, SAMPLERATE)
+    var impulse = oac.createBuffer(1, 1, SAMPLERATE)
+    var bs = new AudioBufferSourceNode(oac);
+    var convolver = new ConvolverNode(oac, {disableNormalization: true});
+
+    impulse.getChannelData(0)[0] = 1.0; // unit impulse function
+    convolver.buffer = impulse; // This does acquire the content
+    impulse.getChannelData(0)[0] = 0.5;
+
+    var channelData = buf.getChannelData(0);
+    for (var i = 0; i < channelData.length; i++) {
+      channelData[i] = 1.0;
+    }
+    bs.buffer = buf;
+    bs.start();
+
+    bs.connect(convolver).connect(oac.destination);
+    return oac.startRendering();
+  }
+};
+
+function allSamplesAtOne(audiobuffer, location) {
+  var buf = audiobuffer.getChannelData(0);
+  for (var i = 0; i < buf.length; i++) {
+    // The convolver can introduce a slight numerical error.
+    if (Math.abs(buf[i] - 1.0) > 0.0001) {
+      assert_true(false, `Invalid value at index ${i}, expecte close to 1.0, found ${buf[i]} when ${location}`)
+      return Promise.reject();
+    }
+  }
+  assert_true(true, `Buffer unmodified when ${location}.`);
+  return Promise.resolve();
+}
+
+for (const test of Object.keys(tests)) {
+  promise_test(async function(t) {
+    var buf = await tests[test](new OfflineAudioContext(1, LENGTH, SAMPLERATE));
+    return allSamplesAtOne(buf, "rendering");
+  }, test);
+};
+</script>