Womble - major audio bugs

Discussion in 'Amateur Video Production' started by Terry Pinnell, Nov 20, 2006.

  1. I've had Womble Wizard for about a week now. After attempting in vain
    throughout the weekend to finish my first serious project I was sorely
    disappointed to conclude that major bugs in its audio track handling
    make it virtually unusable.

    If there are any Womble MPEG DVD Wizard users here who *are*
    successfully making DVD compliant MPGs, complete with accurately
    placed music tracks, I'd greatly appreciate hearing how they do it
    please.

    The key problem I've hit is that, for some imported audio clips, their
    DURATIONS appear to be wrongly displayed and processed. Various
    symptoms result from that, but the most obvious is that an added music
    soundtrack does not finish where Womble's timeline says it does.

    So, on what I'd hoped was the finished DVD, instead of my last piece
    of music, JWilliam.mp3, finishing a few seconds after the final video
    clip faded, as I wanted, it finished a full 2 minutes earlier!

    In this screenshot
    http://www.terrypin.dial.pipex.com/Images/WVW-AudioBug-1.jpg
    the music stopped at about 08:48, whereas when played before export it
    stopped at 10:57.

    It's not just a one-off. I imported 6 music tracks and here's a
    self-explanatory summary:

    <-----Duration mm:ss------>
    Clip Info Timeline
    Name of track Actual Secs mm:ss Error
    ------------- ------ --------- -------- -------
    JWilliam.mp3 2:24 282 4:42 + 96%
    ZipDooDah.mp3 2:29 150 2:30 OK
    Conniff.wma 2:53 173 2:53 OK
    Detective.mp3 1:40 161 2:41 + 61%
    Schools.mp3 1:00 118 1:58 + 97%
    IvorEngine.mp3 0:24 43 0:43 + 79%

    FWIW, I am using what I assume is the latest build. Help>About just
    says 'June 2006 update'

    I emailed Womble Support urgently, and had this prompt reply:
    "Please note that the mp3 support is added via windows Direct Show
    filter API, and it still unstable to a high degree and needs more
    testing and modification."

    Are others getting similar unpredictable results? If so, what
    work-arounds are you using please? Assuming I can believe the accuracy
    of the timing scale, then - although it would be tricky - maybe I
    could manually *calculate* where the music will stop, ignoring the
    timeline display, and base my work on that? Short of trial/error,
    that's all I can think of so far.

    It's a great pity, as one feature of Womble that I really like is
    being able to adjust the volume flexibly with the sound point editor.
     
    Terry Pinnell, Nov 20, 2006
    #1
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  2. Terry Pinnell

    Jukka Aho Guest

    A workaround that might or might not help:

    1) Download and install Audacity.

    <http://audacity.sourceforge.net/>

    2) Open each problematic audio file in Audacity, one at a time. Change
    the sample rate to 48 kHz (the "Project rate" setting on the bottom
    toolbar) and save them as 48 kHz 16-bit WAVs.

    3) Import the WAV files to Womble MPEG DVD Wizard and use them instead
    of the original files.
     
    Jukka Aho, Nov 20, 2006
    #2
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  3. Brilliant, thanks! In fact it's turned out even easier than that...

    I'm not familiar with Audacity and initially had some trouble with its
    interface, and its concept of a 'project' (which seems to mean a
    file?). But eventually worked out how to save ('Export') the WAV at
    48000 Hz using that 'Project rate' button.

    On importing that to Womble, I was delighted to find that it was
    displayed correctly. (The comparison can be shown dramatically by
    using WVW's 2 separate audio channels.)

    There was a very small (3%) increase in the duration. For example, my
    2:24 file became 2:27. Any idea why?

    Experimenting, I then found that even if I simply saved as a WAV at
    the same 44100 Hz, that too was OK in WVW.

    Going one step further, I tried merely resaving immediately in MP3, at
    the existing 44100Hz - and that worked as well!

    While on a roll, I switched to GoldWave, with which I'm a bit more
    comfortable, and tried saving the original MP3 as WMA. And *that* was
    OK in WVW too!

    Love to know why sometime, but that has immediately allowed me to
    finish the DVD. (Well, I say 'finish', but I now see I still have an
    aspect ratio issue with my video clips...!)

    Thanks again for that breakthrough.
     
    Terry Pinnell, Nov 20, 2006
    #3
  4. Terry Pinnell

    Jukka Aho Guest

    I suggested Audacity mainly because it's free and I didn't know you
    already had another audio editor. But GoldWave should do just as well.
    Audacity is a multitrack audio editor. You can import several audio
    files into a single Audacity project, on different tracks, and mix the
    tracks together. (See "Project" -> "Import audio...")
    Where did you compare the original and new length of the clip? In
    Audacity? In some other tool?
    Conversion to 48 kHz format was because the DVD format requires 48 kHz
    audio. Even if you import the file to Womble in its original 44.1 kHz
    format, Womble must then resample it to 48 kHz format itself if it is to
    produce DVD-compliant files.

    The reason why I suggested converting the clip in Audacity was that I
    _know_ Audacity can handle that conversion. On the other hand, what I
    _don't_ know is how well Womble will do the same thing, and whether
    importing 44.1 kHz clips into a Womble DVD project could trigger some
    strange behaviour. (Since you were already experiencing strange
    behaviour in Womble - for which one possible reason _could_ have been
    the difference in the sample rates - I didn't want to risk it.)
    That's does not really make much sense. If Womble was having problems
    with your original 44.1 kHz MP3s, how could resaving in the same format
    change a thing? :)
    (Unless the problematic files were VBR MP3s and you saved them in CBR
    format.)

    Note that neither Audacity nor Goldwave are native MP3 editors. They
    don't have "smart rendering" support for MP3 files. Needlessly resaving
    an audio file in a lossy format, such as MP3 or WMA, leads to... uhm...
    loss of sound quality. Saving to (PCM) WAV format is safer, since (PCM)
    WAV files are lossless.
     
    Jukka Aho, Nov 20, 2006
    #4
  5. Audacity, GoldWave, various players and tag ID progs, and WVW itself -
    all show 2:27.
    No idea why, but I've just repeated it, with same good result. No
    other changes, just a straight Export As MP3.
    http://www.terrypin.dial.pipex.com/Images/WVW-DirectResave.jpg
    Note how that too was fractionally longer, at 2:25.
     
    Terry Pinnell, Nov 20, 2006
    #5
  6. I'm still interested in the puzzle of this apparent contradiction.
    Here's the first of the examples I gave earlier, showing the original
    2:24 file incorrectly handled by WVW, and the one I made by simply
    saving from Audacity, without changing anything, which is handled
    properly.
    http://www.terrypin.dial.pipex.com/Images/WVW-DurationBug-2.jpg

    In case you'd like to take a look, I've also uploaded the two files
    JustWilliamORIGINAL.mp3
    JustWilliamORIGINAL.mp3JustWilliamResavedAudacity44.mp3
    here
    http://download.yousendit.com/4E733F27056D97CB
    http://download.yousendit.com/74CAA6BC42F40005
     
    Terry Pinnell, Nov 21, 2006
    #6
  7. Terry Pinnell

    Jukka Aho Guest

    Like I already suggested in one of my earlier messages to this thread,
    the original file abbears to be a VBR (variable bitrate) MP3 whereas the
    one you exported from Audacity is a CBR (constant bitrate) MP3. See here
    for more information:

    <http://en.wikipedia.org/wiki/Variable_bitrate>

    You can easily see this in e.g. WinAmp. When playing back the original
    file, the bitrate display (the "kbps" field on WinAmp's window) is
    changing all the time, whereas in the new file you exported it stays at
    steady 128 kbps. If you double-click on the scrolling filename display
    in WinAmp you will see some more technical information about the MP3
    file that is currently playing - including whether the file is in the
    CBR or VBR format.

    I believe Womble MPEG Wizard just does not know how to calculate the
    length of a VBR MP3 file.
     
    Jukka Aho, Nov 21, 2006
    #7
  8. Thanks - mystery solved.

    In my usual player, MediaMonkey, it seems to be showing *two* bitrates
    http://www.terrypin.dial.pipex.com/Images/BitratePuzzle1.jpg
    .... and they remain constant!
    But in the Info box I can pop-up, he VBR does indeed have a Yes for
    the original and a No for the straight re-save.

    I'll pass this on to Womble.
     
    Terry Pinnell, Nov 21, 2006
    #8
  9. Terry Pinnell

    STRATEGY Guest


    I had this problem a couple of years ago with Womble and a few MP3's.
    They may very well have been VBR too...


    STRATEGY
     
    STRATEGY, Nov 21, 2006
    #9
  10. Terry Pinnell

    Jukka Aho Guest

    320 kbps would appear to be the highest bitrate that has been used in
    that file. (Only the most demanding segments are stored with a 320 kbps
    bitrate.)

    249 kbps is the average bitrate when considering the whole stream:
    4513515 bytes * 8 / 144 / 1000 =~ 250 kbps. (The file format and its
    internal structures add some overhead to the total size of the file.
    MediaMonkey probably does not include that overhead in its
    calculations - basing them only on the raw audio data - so that's why it
    reports the bitrate as 249 kbps.)
     
    Jukka Aho, Nov 21, 2006
    #10
  11. Thanks Jukka.

    I've notified Womble. It will be interesting to see how long they take
    to fix it.
     
    Terry Pinnell, Nov 21, 2006
    #11
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