Previous 1 2 Next 17 Replies Latest reply: Sep 3, 2013 10:41 AM by pctechtv
DeeKnow Level 1 (0 points)
We've been providing access to recorded QT video materials via SMIL playlists to QuickTime player embed-ed into web pages for some time and until the recent 7.6.6 update had no trouble with playback.

Now when clients who have updated to 7.6.6 view a movie via our SMIL file the video plays ok but its audio is stuttered and distorted, to the point of being incomprehensible. If the same videos are played back directly (ie the qtsrc attrib points directly at the media file) the video and audio play back fine. And if the video is downloaded to the clients desktop it also plays back ok.

This problem is present on Windows Vista and Windows 7, and in recent versions of Firefox and IE. We do not see this problem on our OSX test machines.

Here's a sample of the kind of embed we're using, with qtsrc pointing to the SMIL file in this case:

id="main_movie" type="video/quicktime"
scale="tofit" controller="false" autoplay="true" bgcolor="#000000" enablejavascript="true"
qtsrc="http://OURSERVER.COM/OURPLAYLIST.smi?id=HASHOFID&format=quicktime&playli st=0418060http://OURSERVER.COM/data/FILENAME.mp4;"
align="center" height="180" width="320">

And here's a sample SMIL file as served up to browsers...

<video src="http:/OURSERVER.COM/sample_mpeg4.mp4"/>

note: although our SMIL files usually reference our own encoded mp4 media we see the same problem if the playlist points to other sources, including the sample QT files from

If anyone can suggest how we might solve this, or think of further information that might lead to us solving this problem please reply here and I can furnish it.

thanx in advance,

Windows 7
  • ekhayes Level 1 (0 points)
    Having the exact same issue - not using playlists, just using the smil to write some dynamic text over the video - but everything worked fine until 7.6.6. Would be great if Apple would test this stuff before they push it out the door.
  • Patrick Besong Level 2 (260 points)
    Yes, I've seen this problem too. I hope they fix this soon. Audio is very garbled.
  • ShaneTucker Level 1 (0 points)
    Hi All

    I have managed to fix the audio issues within our setup by replacing the QuickTimeAudioSupport.qtx file located in C:\Program Files\QuickTime\QTSystem\.

    Sizes for these extensions are:
    v7.6.5 - 3,468K
    v7.6.6 - 120K

    So they are clearly very different!

    We are useing H.264 with AAC audio and joing these together using SMIL files. Does anyone know of a potential issue with me using the 7.6.5 extension?

  • hagenhagen Level 1 (0 points)
    We have exactly the same problem. Have to advise our customers not to upgrade to QT 7.6.6. This kind of issue is very atypical of Apple products. Hope they provides a fix quickly. This may be an ominous sign that smil is going to die out. QT is the only actively maintained plugin that plays smil. Perhaps it's time to bite the bullet and switch entirely to flv (if only we can figure out how to do text captioning easily without smil).
  • avdleeuw Level 1 (0 points)
    I'm having similar issues as well, in this case streaming video into the Second Life virtual world. Advising our customers to go back to an earlier version or making changes to local files on their computers is not really an option.

    Is Apple already aware of this issue, apart from this thread? If not, is there a way to make them aware of it?


  • DeeKnow Level 1 (0 points)
    Just a quick update in case anyone happens to notice it, we are STILL experiencing this problem with garbled audio via SMIL requests, even with the last months release of QT 7.6.7
  • Maurice Pelletier Level 1 (0 points)
    Problem still exists with QuickTime 7.6.8!!!! This is so frustrating. Filed a bug back with 7.6.6 and it was flagged as a known issue, but obviously nothing was done to fix it. Also experiencing blank video with only sound with a number of our H.264 content. Reverting back to 7.6.5 fixes this too.

    QuickTime is becoming unsupportable on the Windows platform.

    Any solutions yet?
  • tfthompso Level 1 (0 points)
    I confirm that this is still a problem in QT 7.6.8 (on Windows7), and that replacing QuickTimeAudioSupport.qtx with an older version fixes the problem (still not clear whether it introduces new problems).

    Here's another workaround that fixes the problem temporarily (for that movie only):
    a) In Quicktime, go to Window > Show Movie Properties
    b) Uncheck all movie tracks, then check them again. Now it should play fine.
  • donquibeats Level 1 (0 points)
    I've just updated to 7.6.9 on this Windows 7 machine. Still terrible audio playback for SMIL files. Boo.
  • phloe Level 1 (10 points)
    I'm having this exact same problem

    Very sad to see that Apple haven't responded in any shape or form since April 11!?

    Makes it hard defending using Quicktime as a technology...
  • Patrick Besong Level 2 (260 points)
    I can also confirm that this is still an issue with 7.6.9 on Windows. I've posted another question about it here:

    ShaneTucker, you said you were able to fix the problem by replacing the QuickTimeAudioSupport.qtx file on your computer? Is it available to download somewhere?
  • Patrick Besong Level 2 (260 points)
    I was able to fix this problem with QT SMIL movies by opening them in the QT Player on Windows and showing the AV Controls (under the Window menu). By moving the Pitch Shift control slightly to the left, it cured the gabled audio. Unfortunately, you would have to do this separately for each video you opened and the AV controls are not available for movies that are embedded into a web page. I have also reported this as a bug to Apple and included this info. Perhaps it will help them solve the problem. I sure hope so! This really needs to get fixed
  • phloe Level 1 (10 points)
    I submitted a bugreport too

    Apple just got back to me on the problem and requested a testcase. I've only just uploaded it to the bug.

    What Problem ID does your bug report have? Maybe I should add a reference to yours on mine?

    I'm keeping my fingers crossed.
  • phloe Level 1 (10 points)

    Ok.. My fingers are officially sore now


    No Apple reply here nor any update on the bug report I posted...

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