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Thread: WMV Audio

  1. #1
    dBpoweramp Enthusiast
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    WMV Audio

    I'm chasing some online music concert files (from CBC's Concerts On Demand facility, http://www.cbc.ca/radio2/cod/, and have been using Replay Media Catcher to get the base files.

    Turns out that the base files are in WMV format, being streamed as .asx. Is there a reason why this format would be used?

    When I look at properties of the downloaded files, it gives two different values for the bitrates, as illustrated below. Can anyone annotate this info (properties obtained by hovering over the filename)? I am assuming that the audio quality is equivalent to 128kbps mp3s, that's what they sound like, but I don't know how to interpret the 65kbps.

    Ron


  2. #2
    Administrator
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    Re: WMV Audio

    If there is video also within then it is no easy to guess which is correct (128kbps would be a 5MB file for 5 minutes).

  3. #3
    dBpoweramp Enthusiast
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    Re: WMV Audio

    No video. This is an audio streaming service. I'm trying to figure out why they use WMV format for this, with only audio content, when they could use wma.

    R.

  4. #4
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    Re: WMV Audio

    Some WMA files can contain multiple audio streams (at different qualities), given the length 5M and size 10MB the actual bit rate is 256kbps, if there are multiple streams then each would have part of that.

  5. #5
    dBpoweramp Enthusiast
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    Re: WMV Audio

    I gathered from this set of posts that wmv is in effect wma. I tried changing the v to an a in the extension, and it was picked up by windows media player as a wma file, and played fine. I'll see if SC works with it properly after my late-night auto-update happens.

    Although I actually know nothing, nada, zilch, my hunch is that the 65 bit rate refers to a per-channel value; this means that stereo is 130 (or actually 128), which is what is shown below. I also suspect that the wmv format is a container for both audio and video data; the audio would normally be wma, and there is a facility for video that even empty probably takes up space; hence the file-size being larger than you would expect for 128 files of the given length.

    If anyone actually knows anything about this, do let me know!

    R.
    Last edited by RonM; 08-05-2010 at 09:32 PM.

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