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advancing axmediaplayer.ctl.currentposition RRS feed

  • Question

  • I am implementing the AXMEDIAPLAYER control in a .Net 4 C# application and have been trying to code FF/RW functions.  This is to play .WMA files and only the scan forward native function is available so I was trying to code them both programmatically by using a timer and stepping the .currentposition property.  The problem I have is that when the audio file is playing, after I step the .currentposition property, it is decreasing by a varying amount...between 1 and 1.5.  After testing I have concluded the issue is related to Variable VS Constant bit rate...when the file is encoded using VBR it will step forward/reverse fine, but when it is encoded using CBR it displays the anomaly.

    • Moved by Kristin Xie Wednesday, January 7, 2015 10:01 AM
    Monday, January 5, 2015 2:33 PM

Answers

  • I have confirmed that it doesn't work with CBR already...I converted one of my test files to a similar bit-rate in VBR and it worked perfectly.  These files are being sent to us from a client as 10 Kbps CBR WMA files and I am trying to avoid converting if possible, or at the very least understand why this occurs.  Thank you.

    Hello,

    I have tested it with that control and WMA file which is encoded with CBR, and I could reproduce this issue.

    However, if we set the current pesition by right click on that control, tag to advanced settings to set its value, it will also has this issue.

    Since the media player control and the media player application has the same issue, I assume this is a product issue about Media Player.

    Currently we could not get any workaround to solve this issue, you could consider the other control or avoid encoding with CBR, and I would recommend you consider submit a feedback to see whether the product team have any workaround.

    You could submit a feedback in http://connect.microsoft.com, and share its link here that we could helpy you vote it.
    Thanks for your understanding.

    Regards,

    Carl


    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
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    • Marked as answer by cshaperhd Friday, January 9, 2015 2:09 PM
    Thursday, January 8, 2015 10:18 AM

All replies

  • Hi cshaperhd,

    >>After testing I have concluded the issue is related to Variable VS Constant bit rate...when the file is encoded using VBR it will step forward/reverse fine, but when it is encoded using CBR it displays the anomaly.

    Here are some difference between CBR and  VBR.Constant bit rate (CBR) encoding persists the set data rate to your setting over the whole video clip. Use CBR only if your clip contains a similar motion level across the entire duration.  CBR is most commonly used for streaming video content using the Flash Media Server (rtmp)

     
    Variable bit rate (VBR) encoding adjusts the data rate down and to the upper limit you set, based on the data required by the compressor. VBR takes longer to encode but produces the most favorable results.  VBR is most commonly used for http delivery if video content (http progressive)
     

    We recommend you do not use CBR unless you have a specific need for playback on a device that only supports CBR. Our default VRB mode will produce higher quality  at competitive bitrates.

    So in your scenario, using VBR it will step forward/reverse fine.

    Have a nice day!

    kristin


    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
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    Tuesday, January 6, 2015 8:21 AM
  • The problem is I am not creating the files, I am receiving them from an outside source and they are already encoded in CBR.  I understand the differences, and appreciate the explanation on when/where to use which...what I need to know is why CBR is causing the anomalous behavior when I increment the .currentposition value and how to correct for it.
    Tuesday, January 6, 2015 12:38 PM
  • Hi cshaperhd,

    >>but when it is encoded using CBR it displays the anomaly.

    How did you encoded usng CBR? Can you share with us your encode way? or any others file or code? It could be better for us to reproduce your issue.

    In addtion, i will move your thread to winform forum for better support, since it is a control, this forum is discuss and ask questions about the C# programming language, IDE, libraries, samples, and tools. Thanks

    Have a nice day!

    Kritsin


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    Click HERE to participate the survey.

    Wednesday, January 7, 2015 10:00 AM
  • The problem is I am not creating the files, I am receiving them from an outside source and they are already encoded in CBR.  I understand the differences, and appreciate the explanation on when/where to use which...what I need to know is why CBR is causing the anomalous behavior when I increment the .currentposition value and how to correct for it.

    Sounds like it doesn't work for CBR, to get that confirmed, mind sharing us the file you are dealing with?

    If it is too large, you could encode a smaller one and share it with us.


    remember make the reply as answer and vote the reply as helpful if it helps.

    Wednesday, January 7, 2015 10:11 AM
  • I have confirmed that it doesn't work with CBR already...I converted one of my test files to a similar bit-rate in VBR and it worked perfectly.  These files are being sent to us from a client as 10 Kbps CBR WMA files and I am trying to avoid converting if possible, or at the very least understand why this occurs.  Thank you.
    Wednesday, January 7, 2015 11:35 AM
  • I have confirmed that it doesn't work with CBR already...I converted one of my test files to a similar bit-rate in VBR and it worked perfectly.  These files are being sent to us from a client as 10 Kbps CBR WMA files and I am trying to avoid converting if possible, or at the very least understand why this occurs.  Thank you.

    I am trying to reproduce this issue to look for the solution, workaround or the reason, but failed due to lacking CBR file. That is why I asked for a simple CBR file to test.


    remember make the reply as answer and vote the reply as helpful if it helps.

    Thursday, January 8, 2015 1:57 AM
  • I have confirmed that it doesn't work with CBR already...I converted one of my test files to a similar bit-rate in VBR and it worked perfectly.  These files are being sent to us from a client as 10 Kbps CBR WMA files and I am trying to avoid converting if possible, or at the very least understand why this occurs.  Thank you.

    Hello,

    I have tested it with that control and WMA file which is encoded with CBR, and I could reproduce this issue.

    However, if we set the current pesition by right click on that control, tag to advanced settings to set its value, it will also has this issue.

    Since the media player control and the media player application has the same issue, I assume this is a product issue about Media Player.

    Currently we could not get any workaround to solve this issue, you could consider the other control or avoid encoding with CBR, and I would recommend you consider submit a feedback to see whether the product team have any workaround.

    You could submit a feedback in http://connect.microsoft.com, and share its link here that we could helpy you vote it.
    Thanks for your understanding.

    Regards,

    Carl


    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
    Click HERE to participate the survey.


    • Marked as answer by cshaperhd Friday, January 9, 2015 2:09 PM
    Thursday, January 8, 2015 10:18 AM
  • I've tried the other options I could find...System.Media.Soundplayer won't play .WMA files and System.Windows.Media.MediaPlayer experiences the same anomaly as the Axmediaplayer object, so I'll look into either extraction or conversion of the audio files and submit feedback as suggested.  Thank you all for your help, this has been perplexing me for months. 
    Friday, January 9, 2015 2:09 PM