Maybe we can check supported codecs before returns default value

[nihil-pro]

in passthrough-remuxer.ts line 246
Something like this:

// Since mp4-tools cannot parse full codec string (see 'TODO: Parse codec details'... in mp4-tools)
  // Provide defaults based on codec type
  // This allows for some playback of some fmp4 playlists without CODECS defined in manifest
  if (parsedCodec === 'hvc1' || parsedCodec === 'hev1') {
    // maybe some other
    const codecs = ['hev1.1.2.H150.0', 'hev1.1.6.L120.90', 'hvc1.2.4.L123.B0'];
    const $videoElement = document.createElement('video');
    const checkSupportResults = codecs
      .map((codec) => $videoElement.canPlayType(`video/mp4; codecs="${codec}"`))
      .filter((result) => result === 'probably');

    if (checkSupportResults.length == 0) return 'hvc1.1.c.L120.90'; // maybe something else
    return checkSupportResults[0];
  }

[robwalch]

This should be addressed and commented on in these PRs:

• Add codec string parsing for h264, h265, and mp4a #4996
• Feature/hvcc parser #5024