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Problems with "spectrum" example

  • Hi,
    I'm having problems with the "Spectrum" Example (as well as in an app of mine that's based on that code). This occurs when playing back a song from a WAV file.

    Problem #1 is only in Qt 5.4.1, and does not appear in Qt 5.3.1
    The spectrum display flashes blank every few seconds; deeper exploration seems to indicate that the spectrum is intermittently returning all zeros.

    Problem #2 occurs in both 5.4 and 5.3, and is also intermittent. The "audioNotify" signal stops getting emitted, and the spectrum stops getting updated, even though the song continues to play. The debug output of the engine shows this right before the audioNotify signals stop:

    Engine::audioStateChanged from ActiveStatetoActiveState
    Engine::audioStateChanged from ActiveStatetoActiveState

    (Yes, it prints it twice)
    Pausing and restarting the song will cause the the problem to go away.

    Is anyone else having these problems? I've played with it quite a bit, and can supply more debugging clues. But I didn't want to overwhelm the first post with what might be superfluous details.

    FYI, this is on Mac OS X, and has been a problem from OS 10.8 onwards.

    Any insight appreciated. Thanks very much!

  • Lifetime Qt Champion


    Sounds like there might be a bug in the QtMultimedia module. You should take a look at the bug report system to see if it's something known. If not please consider opening a new report providing as much details you can.

  • @SGaist
    Thanks! I didn't see any bug reports that looked relevant. I'll file one.

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