Major bug in latest Windows 10 media players for fragmented mp4 files RRS feed

  • Question

  • My Windows 10 machine updated itself and since the new update, it cannot play fragmented mp4 files properly. 

    Here is an example file:

    After you start the player, you need to seek it a few times for it to play properly. It was fine before the update.

    This file plays fine in Windows 10. Please check this.

    Wednesday, November 30, 2016 6:24 AM

All replies

  • Can somebody play the file and check it. It is a consistent bug.
    Thursday, December 1, 2016 3:44 AM
  • Can somebody play the file and check it. It is a consistent bug.

    Why are you complaining about issues with Windows Media Player after a Windows 10 update in this Forum?

    This is not a Windows Media Player issues Forum or a Windows 10 issues Forum.

    Perhaps you should try here and browse to find either Windows 10 or Windows Media Player to ask a question about. And at the link try spending some time to learn how to use the browse and filter areas so you can best find where or what to ask a question about before you bother posting a question.

    If you spend time to learn how to use it you may end up posting correctly like this post Windows Media Player which "Applies to Music, Movies & TV|Windows Media Player".

    La vida loca

    Thursday, December 1, 2016 3:56 AM
  • Because, inherently, this is a media foundation source reader issue.

    If you take the same file, and try to read it via source reader (IMFSourceReader) on a Windows 10 machine, it reads "randomly" and quits. Try MFCopy with this file and you will see it fail.

    The same code (MFCopy) will read the file fine on Windows 8.1 and print out proper timestamps.

    Does this sound fair to you?

    • Edited by Kadambi Thursday, December 1, 2016 6:26 AM
    Thursday, December 1, 2016 6:25 AM
  • The posting looks relevant. It is not the problem of Windows Media Player exactly. it more looks like a problem with underlying Media Foundation components, I would say that fragmented MP4 media source does not time stamp samples accurately and they pass decoding without proper time indication for playback. Looks like API bug indeed.

    Thursday, December 1, 2016 6:57 AM
  • Roman,

    Exactly. I can confirm this with a simple IMFSourceReader code. Just read the file with source reader and i print out timestamps. It does not do it right and it "quits" before reaching the end of the file.

    The same code is fine on Windows 8.1.

    This happened recently, like about 15-20 days ago, when my machine downloaded the updates.

    Thursday, December 1, 2016 8:23 AM
  • Roman commented at Bug in Media Foundation MPEG-4 File Source related to timestamping video frames of a fragmented MP4 file that this problem still exists as of 11/11/2016

    As of 12/9/2016, I see a new updated mp4srcsink.dll, but I still see problems when first loading this file in Windows Media Player.  The display initially remains blank and timestamps increment randomly until they are way past the duration of the file.  After seeking once, the file plays back correctly.   Also hangs MFCopy, never completing. 

    Relevant files: 

    mfplat.dll 10.0.14393.479 - 11/11/2016

    mfp4srcsink.dll 10.0.14393.576 - 12/9/2016

    Is there an official bug report filed against this?


    Thursday, December 15, 2016 6:31 PM
  • Thank you for your input.

    Yes, it still exists. MFCopy also does not work due to the same bug.

    I hope to hear from Microsoft here. Otherwise, I will be filing a bug report.

    Friday, December 16, 2016 5:28 AM
  • Any updates?
    Monday, December 19, 2016 4:52 AM
  • It appears that you will either hear from Microsoft immediately or not at all.  If I were you, I would go ahead and file a bug.
    Monday, December 19, 2016 5:00 PM
  • I am working with MS paid tech support. It is in investigation phase. I will report back on findings here.
    Wednesday, February 1, 2017 6:05 AM
  • For the record - it looks like they fixed the bug in Win 10 with updates as of now.

    Sunday, May 21, 2017 6:31 PM