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Virtualdub (Fixing Audio) !?

Discussion in 'MPEG-1 and MPEG-2 encoding (AVI to DVD)' started by Slug716, Nov 12, 2004.

  1. Slug716

    Slug716 Member

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    When I load some movies in Virtualdub not all a box pops up saying this


    [bold]"Virtualdub has detected an inproper VBR audio encoding in the source avi file (audio stream 1) the current preference is to rewrite the audio header with standard CBR values during processing for better compatibility this may introduce up to 18904 ms of skew from the video stream if this is unacceptable decompress the entire audio stream to an uncompressed WAV file and recompress with a constant bitrate encoder (bitrate 128.4 + 16.5 kbps)"[/bold]


    Can some one please explain to me what this means and how I can fix the audio step by step

    Im new to all this so any help I would appricate
     
  2. aldaco12

    aldaco12 Active member

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    Lucky you! You found a really BIG problem! Luckily it happened also to me and I found the solution (alas, in another forum!) and now I'm able to answer you.

    1. extract the .WAV from the movie with Virtualdub. Set Audio X [bold]Full Processing Mode [/bold] then do Save WAV (--> very large - 1 GB - WAV for a movie! But this is necessary or you'll fail if Audio is set on [bold]Direct Stream Copy[/bold])
    2. encode the .WAV file into a .MP2 file with BeSweet (very good compressor. You can use it also if TMPGenc cannot load/decode the movie's audio (generally it happens on MPGs) but you must set Vitutaldub on [bold]Direct Stream Copy[/bold] to extract the .WAV you're unable to decode); it's better for you use the useful BeSweet GUI. You just have to a) tell it where BeSweet it b)select the profile MP2 for SVCD c) tell it which is the file to compress and the output MP2 name).

    After that press [WAV to MP2] and your > 1 GB WAV will become a 300 Mb MP2. You may join this sound when you convert the AVI to Video-CD mpeg with TMPGenc (click 'browse' in the 'audio input' screen or, if you're doing a KVCD special Video-CD, multiplex (choose as Type: "non-standard video-cd"). As soon you've got the MP2 you can delete the huge .WAV to free your HD.


    Non at all easy, is it?
     
    Last edited: Nov 12, 2004
  3. Slug716

    Slug716 Member

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    thanks aldaco12 4 the help

    a few questions when i save the audio as a wav (Full Processing Mode) does it matter what audio compression i use cause theres a whole list of them when i click on the compression tab under audio or should i leave that alone

    and after i extract the audio (Wav) from the avi what should i select to save the movie "save as avi" or "save old format avi"
     
  4. aldaco12

    aldaco12 Active member

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    >> when i save the audio as a wav (Full Processing Mode) does it matter what audio compression i use cause theres a whole list of them when i click on the compression tab under audio or should i leave that alone?

    Leave it alone. You choose Full Processing Mode to avoid compressing the sound, keeping it good (and huge). I don't think that on 'Full Processing Mode' Virtualdub compresses the sound. It's later, with BeSweet, that yoou'll compress it and your 1 GB .WAV file will become a 200 MB .MP2 file. Simply, under Audio, you should have checked 'Source Audio' and 'Full Processing Mode'. No other setting is required.


    >> and after i extract the audio (Wav) from the AVI what should i select to save the movie "save as avi" or "save old format avi"

    I don't think you should have problems with the audio unless you convert AVI-->MPG, therefore if you leave the AVI as it is, you can see it on the PC.
    The .MP2 sound you just made shall be multiplexed with the MPG you make with TMPGenc (or used firectly with you convert AVI-->MPG using the MP2 as 'audio input' in TMPGenc's main screen).
     
  5. Slug716

    Slug716 Member

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    Thanks again aldaco12 thats working great on my movies no problem

    except when i try to do it with this one video file a box pops up and says

    [bold]No audio decompressor can be found to decompress the source audio format[/bold]

    This is the only file im having a problem with now

    could u please expain to me what this means and if i can fix it

    Thank You
     
  6. aldaco12

    aldaco12 Active member

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    This is the problem I was speaking to you about before. You can't read the audio with TMPGenc. In http://www.afterdawn.com/guides/archive/svcd_to_vcd_from_cd_images_or_mpeg_files_page_3.cfm you can find tricks to teach TMPGenc how to read the audio.

    Otherwise, you can use my trick:


    ".... BeSweet is very good.... You can use it also if TMPGenc cannot load/decode the movie's audio (generally it happens on MPGs) but you must set Vitutaldub on Direct Stream Copy to extract the .WAV you're unable to decode)."
    In this case, I hope you aren't simultaneously unable to decode the .WAV and to extract .WAV 'Full Processing Mode' because there's a wrong VBR, otherwise you have to do that twice (one to extract the Audio "Direct Stream Copy" for compressing it to MP2 - and now you should able to decode it - and the 2nd to extract the now loadable audio created by BeSweet "Full processing mode" to correct the bad VBR setting.
    (I hope it works. I neved had this problem)
     
    Last edited: Nov 15, 2004
  7. Slug716

    Slug716 Member

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    thanks aldaco

    but now im pretty sure its just a corrupt file no fixing it i cant even convert the audio just keeps giving me errors

    anyway i have another quesion off topic

    When u get a video file where the audio is out of sync is there anyway to fix that so it plays perfectly in my dvd player i think you can do it in virtualdub but in not really sure how to


    Would I just extraxt the audio & video sepertaly than convert it in tmpgenc or do i have to do somethin else
     
  8. Drizz

    Drizz Guest

    I also was wondering if there was a way to fix a video file where the audio is out of sync, to it will play perfect in my dvd player? Anyone?
     
  9. Phu

    Phu Member

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  10. mike187

    mike187 Guest

    I just got vurtualdub and besweet and i have no clue how to use it can anyone please help me i would truly appreciate it.
     

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