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<title>MediaRecorder {audio|video}bitsPerSecond attributes</title>
<link rel="help" href="https://w3c.github.io/mediacapture-record/MediaRecorder.html">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
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<script>

/*
 * The bitrate handling is difficult to test, given that the spec uses text such
 * as: "values the User Agent deems reasonable" and "such that the sum of
 * videoBitsPerSecond and audioBitsPerSecond is close to the value of recorder’s
 * [[ConstrainedBitsPerSecond]] slot". For cases like that this test tries to
 * use values that are reasonable for the tested track types. Should a UA vendor
 * see a need to update this to fit their definition of reasonable, they should
 * feel free to do so, doing their best to avoid regressing existing compliant
 * implementations.
 */

async function getStream(t, constraints) {
  const stream = await navigator.mediaDevices.getUserMedia(constraints);
  const tracks = stream.getTracks();
  t.add_cleanup(() => tracks.forEach(tr => tr.stop()));
  return stream;
}

function getAudioStream(t) {
  return getStream(t, {audio: true});
}

function getVideoStream(t) {
  return getStream(t, {video: true});
}

function getAudioVideoStream(t) {
  return getStream(t, {audio: true, video: true});
}

const AUDIO_BITRATE = 1e5;      // 100kbps
const VIDEO_BITRATE = 1e6;      // 1Mbps
const LOW_TOTAL_BITRATE = 5e5;  // 500kbps
const HIGH_TOTAL_BITRATE = 2e6; // 2Mbps
const BITRATE_EPSILON = 1e5;    // 100kbps

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t));
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
}, "Passing no bitrate config results in defaults");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    bitsPerSecond: 0,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond, 0,
    BITRATE_EPSILON);
}, "Passing bitsPerSecond:0 results in targets close to 0");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    audioBitsPerSecond: 0,
  });
  assert_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
}, "Passing only audioBitsPerSecond:0 results in 0 for audio, default for video");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    videoBitsPerSecond: 0,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_equals(rec.videoBitsPerSecond, 0);
}, "Passing only videoBitsPerSecond:0 results in 0 for video, default for audio");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    bitsPerSecond: 0,
    audioBitsPerSecond: AUDIO_BITRATE,
    videoBitsPerSecond: VIDEO_BITRATE,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond, 0,
    BITRATE_EPSILON);
}, "Passing bitsPerSecond:0 overrides audio/video-specific values");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    bitsPerSecond: HIGH_TOTAL_BITRATE,
    audioBitsPerSecond: 0,
    videoBitsPerSecond: 0,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond,
    HIGH_TOTAL_BITRATE, BITRATE_EPSILON);
}, "Passing bitsPerSecond overrides audio/video zero values");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    bitsPerSecond: HIGH_TOTAL_BITRATE,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
  assert_approx_equals(rec.audioBitsPerSecond + rec.videoBitsPerSecond,
    HIGH_TOTAL_BITRATE, BITRATE_EPSILON);
}, "Passing bitsPerSecond sets audio/video bitrate values");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    audioBitsPerSecond: AUDIO_BITRATE,
  });
  assert_equals(rec.audioBitsPerSecond, AUDIO_BITRATE);
  assert_not_equals(rec.videoBitsPerSecond, 0);
}, "Passing only audioBitsPerSecond results in default for video");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    videoBitsPerSecond: VIDEO_BITRATE,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_equals(rec.videoBitsPerSecond, VIDEO_BITRATE);
}, "Passing only videoBitsPerSecond results in default for audio");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioStream(t), {
    videoBitsPerSecond: VIDEO_BITRATE,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_equals(rec.videoBitsPerSecond, VIDEO_BITRATE);
}, "Passing videoBitsPerSecond for audio-only stream still results in something for video");

promise_test(async t => {
  const rec = new MediaRecorder(await getVideoStream(t), {
    audioBitsPerSecond: AUDIO_BITRATE,
  });
  assert_equals(rec.audioBitsPerSecond, AUDIO_BITRATE);
  assert_not_equals(rec.videoBitsPerSecond, 0);
}, "Passing audioBitsPerSecond for video-only stream still results in something for audio");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioStream(t), {
    bitsPerSecond: HIGH_TOTAL_BITRATE,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
}, "Passing bitsPerSecond for audio-only stream still results in something for video");

promise_test(async t => {
  const rec = new MediaRecorder(await getVideoStream(t), {
    bitsPerSecond: HIGH_TOTAL_BITRATE,
  });
  assert_not_equals(rec.audioBitsPerSecond, 0);
  assert_not_equals(rec.videoBitsPerSecond, 0);
}, "Passing bitsPerSecond for video-only stream still results in something for audio");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t));
  t.add_cleanup(() => rec.stop());
  const abps = rec.audioBitsPerSecond;
  const vbps = rec.videoBitsPerSecond;
  rec.start();
  assert_equals(rec.audioBitsPerSecond, abps);
  assert_equals(rec.videoBitsPerSecond, vbps);
}, "Selected default track bitrates are not changed by start()");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    audioBitsPerSecond: AUDIO_BITRATE,
    videoBitsPerSecond: VIDEO_BITRATE,
  });
  t.add_cleanup(() => rec.stop());
  const abps = rec.audioBitsPerSecond;
  const vbps = rec.videoBitsPerSecond;
  rec.start();
  assert_equals(rec.audioBitsPerSecond, abps);
  assert_equals(rec.videoBitsPerSecond, vbps);
}, "Passed-in track bitrates are not changed by start()");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioVideoStream(t), {
    bitsPerSecond: HIGH_TOTAL_BITRATE,
  });
  t.add_cleanup(() => rec.stop());
  const abps = rec.audioBitsPerSecond;
  const vbps = rec.videoBitsPerSecond;
  rec.start();
  assert_equals(rec.audioBitsPerSecond, abps);
  assert_equals(rec.videoBitsPerSecond, vbps);
}, "Passing bitsPerSecond for audio/video stream does not change track bitrates in start()");

promise_test(async t => {
  const rec = new MediaRecorder(await getAudioStream(t), {
    bitsPerSecond: LOW_TOTAL_BITRATE,
  });
  t.add_cleanup(() => rec.stop());
  const abps = rec.audioBitsPerSecond;
  const vbps = rec.videoBitsPerSecond;
  rec.start();
  assert_approx_equals(rec.audioBitsPerSecond, LOW_TOTAL_BITRATE,
    BITRATE_EPSILON);
  assert_equals(rec.videoBitsPerSecond, 0);
  assert_not_equals(rec.audioBitsPerSecond, abps);
  assert_not_equals(rec.videoBitsPerSecond, vbps);
}, "Passing bitsPerSecond for audio stream sets video track bitrate to 0 in start()");

promise_test(async t => {
  const rec = new MediaRecorder(await getVideoStream(t), {
    bitsPerSecond: HIGH_TOTAL_BITRATE,
  });
  t.add_cleanup(() => rec.stop());
  const abps = rec.audioBitsPerSecond;
  const vbps = rec.videoBitsPerSecond;
  rec.start();
  assert_equals(rec.audioBitsPerSecond, 0);
  assert_approx_equals(rec.videoBitsPerSecond, HIGH_TOTAL_BITRATE,
    BITRATE_EPSILON);
  assert_not_equals(rec.audioBitsPerSecond, abps);
  assert_not_equals(rec.videoBitsPerSecond, vbps);
}, "Passing bitsPerSecond for video stream sets audio track bitrate to 0 in start()");
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