Quelle test_decoderDelay.html Sprache: HTML

products/Sources/formale Sprachen/C/Firefox/dom/media/webaudio/test/test_decoderDelay.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8" />
  <title>Test that decoder delay is handled</title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
  <script class="testbody" type="text/javascript">
    SimpleTest.waitForExplicitFinish();
    const {AppConstants} = SpecialPowers.ChromeUtils.importESModule(
      "resource://gre/modules/AppConstants.sys.mjs"
    );

    var tests_half_a_second = [
      "half-a-second-1ch-44100-aac.mp4",
      "half-a-second-1ch-44100-flac.flac",
      "half-a-second-1ch-44100-libmp3lame.mp3",
      "half-a-second-1ch-44100-libopus.opus",
      "half-a-second-1ch-44100-libopus.webm",
      "half-a-second-1ch-44100-libvorbis.ogg",
      "half-a-second-1ch-44100.wav",
      "half-a-second-1ch-48000-aac.mp4",
      "half-a-second-1ch-48000-flac.flac",
      "half-a-second-1ch-48000-libmp3lame.mp3",
      "half-a-second-1ch-48000-libopus.opus",
      "half-a-second-1ch-48000-libopus.webm",
      "half-a-second-1ch-48000-libvorbis.ogg",
      "half-a-second-1ch-48000.wav",
      "half-a-second-2ch-44100-aac.mp4",
      "half-a-second-2ch-44100-flac.flac",
      "half-a-second-2ch-44100-libmp3lame.mp3",
      "half-a-second-2ch-44100-libopus.opus",
      "half-a-second-2ch-44100-libopus.webm",
      "half-a-second-2ch-44100-libvorbis.ogg",
      "half-a-second-2ch-44100.wav",
      "half-a-second-2ch-48000-aac.mp4",
      "half-a-second-2ch-48000-flac.flac",
      "half-a-second-2ch-48000-libmp3lame.mp3",
      "half-a-second-2ch-48000-libopus.opus",
      "half-a-second-2ch-48000-libopus.webm",
      "half-a-second-2ch-48000-libvorbis.ogg",
      "half-a-second-2ch-48000.wav",
    ];

    // Those files are almost exactly half a second, but don't have enough pre-roll/padding
    // information in the container, or the container isn't parsed properly, so
    // aren't trimmed appropriately.
    // vorbis webm, opus mp4, aac adts
    var tests_adts = [
      "half-a-second-1ch-44100-aac.aac",
      "half-a-second-1ch-44100-libopus.mp4",
      "half-a-second-1ch-44100-libvorbis.webm",
      "half-a-second-1ch-48000-aac.aac",
      "half-a-second-1ch-48000-libopus.mp4",
      "half-a-second-1ch-48000-libvorbis.webm",
      "half-a-second-2ch-44100-aac.aac",
      "half-a-second-2ch-44100-libopus.mp4",
      "half-a-second-2ch-44100-libvorbis.webm",
      "half-a-second-2ch-48000-aac.aac",
      "half-a-second-2ch-48000-libopus.mp4",
      "half-a-second-2ch-48000-libvorbis.webm",
    ];

    // Other files that have interesting characteristics.
    var tests_others = [
      {
        // Very short VBR file, 16 frames of audio at 44100. Padding spanning two
        // packets.
        "path": "sixteen-frames.mp3",
        "frameCount": 16,
        "samplerate": 44100,
        "fuzz": {}
      },
      {
        // This is incorrect (the duration should be 0.5s exactly)
        // This is tracked in https://github.com/mozilla/mp4parse-rust/issues/404
        "path":"half-a-second-1ch-44100-aac-afconvert.mp4",
        "frameCount": 22464,
        "samplerate": 44100,
        "fuzz": {
          "android": 2
        }
      },
      {
        // Bug 1856145 - Invalid OGG file with busted granulepos in the
        // bytestrem, but we should be able to recover and play it properly.
        // This triggers a bug in the decoder delay trimming logic.
        "path": "1856145.ogg",
        "samplerate": 8000,
        "frameCount": 8192,
        "fuzz" : {}
      },
      {
        // Bug 1924925 - Valid flac file that is very small.
        "path": "tiny.flac",
        "samplerate": 22500,
        "frameCount": 2271,
        "fuzz" : {}
      }
    ];

    var all_tests = [tests_half_a_second, tests_adts, tests_others].flat();

    var count = 0;
    function checkDone() {
      if (++count == all_tests.length) {
        SimpleTest.finish();
      }
    }

    async function doit() {
      var context = new OfflineAudioContext(1, 128, 48000);
      tests_half_a_second.forEach(async testfile => {
        var response = await fetch(testfile);
        var buffer = await response.arrayBuffer();
        var decoded = await context.decodeAudioData(buffer);
        is(
          decoded.duration,
          0.5,
          "The file " + testfile + " is half a second."
        );
        // Value found empirically after looking at the files. The initial
        // amplitude should be 0 at phase 0 because those files are sine wave.
        // The compression is sometimes lossy and the first sample is not always
        // exactly 0.0.
        ok(
          Math.abs(decoded.getChannelData(0)[0]) <= 0.022,
          `The start point for ${testfile} is correct ${ decoded.getChannelData(0)[0] }`
        );
        checkDone();
      });
      tests_adts.forEach(async testfile => {
        var response = await fetch(testfile);
        var buffer = await response.arrayBuffer();
        var decoded = await context.decodeAudioData(buffer);
        // Value found empirically after looking at the files. ADTS containers
        // don't have encoder delay / padding info so we can't trim correctly.
        ok(
          Math.abs(decoded.duration - 0.5) < 0.02,
          `The ADTS file ${testfile} is about half a second (${decoded.duration}, error: ${Math.abs(decoded.duration-0.5)}).`
        );
        checkDone();
      });
      tests_others.forEach(async test => {
        // Get an context at a specific rate to avoid duration changes due to resampling.
        var contextAtRate = new OfflineAudioContext(1, 128, test.samplerate);
        var response = await fetch(test.path);
        var buffer = await response.arrayBuffer();
        var decoded = await contextAtRate.decodeAudioData(buffer);
        const fuzz = test.fuzz[AppConstants.platform] ?? 0;
        ok(Math.abs(decoded.length - test.frameCount) <= fuzz, `${test.path} is ${decoded.length} frames long`);
        checkDone();
      });
    }

    doit();
  </script>
</body>
</html>

Messung V0.5

¤ Dauer der Verarbeitung: 0.3 Sekunden ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.