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/**
* Returns true if a given AudioPort is completely filled with zero samples.
* "AudioPort" is a short-hand for FrozenArray<FrozenArray<Float32Array>>.
*
* @param {FrozenArray<FrozenArray<Float32Array>>} audioPort
* @returns bool
*/
function IsAllZero(audioPort) {
for (let busIndex = 0; busIndex < audioPort.length; ++busIndex) {
const audioBus = audioPort[busIndex];
for (let channelIndex = 0; channelIndex < audioBus.length; ++channelIndex) {
const audioChannel = audioBus[channelIndex];
for (let sample = 0; sample < audioChannel.length; ++sample) {
if (audioChannel[sample] != 0)
return false;
}
}
}
return true;
}
const kRenderQuantumFrames = 128;
const kTestLengthInSec = 1.0;
const kPulseDuration = 100;
/**
* Checks the |outputs| argument of AudioWorkletProcessor.process() and
* send a message to an associated AudioWorkletNode. It needs to be all zero
* at all times.
*
* @class ZeroOutputsCheckProcessor
* @extends {AudioWorkletProcessor}
*/
class ZeroOutputsCheckProcessor extends AudioWorkletProcessor {
constructor() {
super();
this.startTime = currentTime;
this.counter = 0;
}
process(inputs, outputs) {
if (!IsAllZero(outputs)) {
this.port.postMessage({
type: 'assertion',
success: false,
message: 'Unexpected Non-zero sample found in |outputs|.'
});
return false;
}
if (currentTime - this.startTime >= kTestLengthInSec) {
this.port.postMessage({
type: 'assertion',
success: true,
message: `|outputs| has been all zeros for ${kTestLengthInSec} ` +
'seconds as expected.'
});
return false;
}
// Every ~0.25 second (100 render quanta), switch between outputting white
// noise and just exiting without doing anything. (from crbug.com/1099756)
this.counter++;
if (Math.floor(this.counter / kPulseDuration) % 2 == 0)
return true;
let output = outputs[0];
for (let channel = 0; channel < output.length; ++channel) {
for (let sample = 0; sample < 128; sample++) {
output[channel][sample] = 0.1 * (Math.random() - 0.5);
}
}
return true;
}
}
registerProcessor('zero-outputs-check-processor', ZeroOutputsCheckProcessor);