4 Replies Latest reply: Apr 4, 2006 7:36 AM by doclittle
doclittle Level 1 Level 1
Since upgrading to QT Player 7.0.3 and tiger (10.4.3), none of my MP4 (AAC) files play smoothly on QT. Both the audio and video play with intermittent jerks. Playback in VLT is fine, and playback in QT 6.x was not problematic. I have reinstalled QT 7.0.1 and then 7.0.3, but to no avail. This is an unexpected glitch in my QT 7.0.3 because QT is adertised in the following glowing terms:
"QuickTime has a legacy of supporting and developing the latest digital media standards ensuring that you can create and play back the widest range of standard formats in the industry with QuickTime... In fact, the ISO chose the QuickTime file format as the basis for the MPEG-4 file format."
And "With the free QuickTime Player or browser plug-in, you can play back any compliant MPEG-4 file."
These PR statements are not ringing true with me.
Does anybody else have this problem? Does anybody have a fix for me?

PB G4, iBook G4, iBook G3, eMac   Mac OS X (10.4.3)  
  • QuickTimeKirk Level 9 Level 9
    QuickTime 7 nows supports higher frequencies from audio sources.
    Third party software can "alter" these settings.
    The Audio MIDI Setup (Utilities folder) can "adjust" the playback settings and "restore" your video files "playability".
    Open the app, change the output format to 44100Hz, and try the file again.
    You may need to do this each time a non standard formats is used.
    This "fix" also affects FireWire devices and other Apple software (FCP, AE) and other "audio" issues some content providers may be experiencing.
  • doclittle Level 1 Level 1
    Open the app, change the output format to 44100Hz,
    and try the file again.
    You may need to do this each time a non standard
    formats is used.

    Thanks for the info. This was a work around "fix" I noticed in another thread. It seems to have unhappy side effects in other aps--which means it is not a good fix. However, I did try it when I first noticed it in the other thread. It did not work for me when I tried it then, and it does not work for me now. My output format is and has been set at 44100 Hz. My MP4 files still do not play correctly.

    Concerning the terminology of "non-standard format," as far as I know my files are standard format--straight from a relatively new camera. However, I readily admit I do not know what a "non-standard format" might be. But even if my files might be "non-standard" (whatever that means), it baffles me that this problem did not occur with QT 6.x but does with QT 7.x. The sensible thing to assume with a QT upgrade (required for Tiger, no less--this is not an optional upgrade) is that QT 7.x should be backwards compatible with "non-standard" files that played flawlessly on QT 6.x.

    Anyway, thanks for the hint. I am still looking for a solution.
  • James Bevan Level 1 Level 1
    I play MP4 movies on QT on an iBook G4 with no problem. However, I have found that files become fragmented if they are transferred to a hard drive more than one at a time. I have no idea whether this has anything to do with YOUR problem.

    If I copy a problem mp4 file from the internal drive to an external drive -- one at a time -- the new copy plays without jerks. If I grab two mp4s and copy them to my external drive (even if they were both non-jerky to begin with) they will both become jerky.

    I have a number of mp4 files on an external drive. They were put there one at a time and they play with no problem at all.
  • doclittle Level 1 Level 1
    I was finally able to solve this QT stuttering problem by deleting all QT preference files from my user account (~/Library/Preferences/com.apple.*).
    Got the hint to do so from this discussion: "Any Fix For Video Stuttering?" at http://discussions.apple.com/thread.jspa?threadID=373530&start=0&tstart=0