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  1. Thread AuthorThread Author   #1  
    espr3ss0's Avatar
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    Default Demux

    Hi me again ;-p ...

    Noticed recently, instead of encoding from AVI to MP4 I could save a lot of time with a 'Demux' Application for the Mac. Then all that's needed is the 'Media Container' instead of AVI with no change to the Video & Audio into an MP4 container and maybe even M4V. Trouble is, I have no idea which App for the Mac to use !?, but I did come across "ffmpeg" which uses Mac's Terminal based command line input. The other trouble with this is the 'download source'.

    Any thoughts ? o_O
  2. #2  
    Karenkcoulter's Avatar

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    Default Demux

    Not sure exactly what you're getting at but I'll give it a shot anyway…

    I think basically you want a way to get the video out of the avi wrapper and into a mp4 wrapper so that iTunes can play it? And you want to do that without re-encoding the whole file?

    Well assuming that the internal parts of avi and mp4 are the same (which I don't know), the only Mac program I've come across that can change the "wrapper" without re-encoding the whole file is Simple MovieX. It is the only thing I know of that can do native editing rather than transcoding. I use Simple MovieX to chop out commercials and save the video without transcoding it. But I'm starting and ending with an mp4 or m4v. I don't know if it will work for what you want (it is not a free program btw).
  3. Thread AuthorThread Author   #3  
    espr3ss0's Avatar
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    Default Re: Demux

    Your pretty much right, no extra coding involved. I had come across "Simple MovieX" a while ago and didn't give it much thought, I ended with "Mpeg Streamclip" which isn't much to run & very easy to edit Video. I used it for the same reasons but now I find even though it has on the menu 'Demux' it's strangely disabled. I've come across very frequently "ffmpeg" but seems too much to install.

    If I'm not wrong what your saying, SMX will do AVI wrapper to MP4 ?
  4. #4  
    Karenkcoulter's Avatar

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    Default Demux

    Not sure on the avi to mp4. But probably avi to mov which would still be iTunes compatible. I'd try it for you but I don't have any avi files to work with.

    If you have a relatively short avi or know where I can find a free and legal one, I'd be happy to give it a try.
  5. Thread AuthorThread Author   #5  
    espr3ss0's Avatar
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    Default Re: Demux

    By Demuxing what I mean is, the wrapper is AVI as with MP4 but the content should be extractable both the Audio & Video from the AVI wrapper to MP4.

    Is this possible ?
  6. #6  
    kch50428's Avatar

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    Default Re: Demux

    Quote Originally Posted by espr3ss0 View Post
    By Demuxing what I mean is, the wrapper is AVI as with MP4 but the content should be extractable both the Audio & Video from the AVI wrapper to MP4.

    Is this possible ?
    Convert AVI to MP4? There are any number of programs out there that 'transcode' files from one format to another. Google will help you find one.
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  7. #7  
    Karenkcoulter's Avatar

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    Default Demux

    Quote Originally Posted by kch50428 View Post
    Convert AVI to MP4? There are any number of programs out there that 'transcode' files from one format to another. Google will help you find one.
    But what he's looking to do is avoiding the transcoding and just changing format which is possible sometimes. Transcoding takes a good bit of time and there is always some loss if quality.
  8. #8  
    Karenkcoulter's Avatar

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    Default Demux

    Quote Originally Posted by espr3ss0 View Post
    By Demuxing what I mean is, the wrapper is AVI as with MP4 but the content should be extractable both the Audio & Video from the AVI wrapper to MP4.

    Is this possible ?
    Like I said above, I'm not sure about that particular transformation but Simple MovieX does do saving in some cases rather than transcoding. If you can PM me an avi file or point me to a free legal non-explicit one on the web, I'd be happy to try it with Simple MovieX for you.
  9. Thread AuthorThread Author   #9  
    espr3ss0's Avatar
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    Default Re: Demux

    I will try "Simple MovieX", I've been trying to figure "AviDemux" which outputs fine for coping the Video but leaves out the Audio for unknown reasons. I will probably miss on sending a file, thanks all the same.
  10. Thread AuthorThread Author   #10  
    espr3ss0's Avatar
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    Default Re: Demux

    I tried "Simple MovieX" and can't see any 'Demuxing' options, obviously I'm missing something but all I end up with is more encoding. Is there an easy Guide for it ? Sticking with "Handbrake" for now. Also looked at "MKVToolNix" which can switch the Container to .MKV but it also converts the Video 'FourCC' and is not readable to "Subler" :-( I like "Subler" but it won't process AVI's
  11. #11  
    Karenkcoulter's Avatar

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    Default Demux

    You want the "Save As…" option in Simple MovieX which, if available, will save the file in the new selected format without transcoding.
  12. #12  
    Karenkcoulter's Avatar

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    Default Re: Demux

    Here's the info from Simple MovieX's help file:

    Saving and Converting
    Once you're done with editing, it's time to save your work.

    The important thing to remember is: You can't always save your work in the original format.
    What ? Wasn't this supposed to be a nice movie editor for the rest of us ?

    OK, we're not perfect, but SimpleMovieX is still probably one of the best product to this regard: It supports native editing of QuickTime, AVI, MPEG-1, MPEG-2 and MPEG-4.

    Understanding limitations
    Saving has a few limitations coming from the underlying multimedia technology. First of all, some codecs are one-way, they just open and decode but cannot encode or save. This is the case for example of mp3. In this case, the only possible saving options are QuickTime format, that always works, or re-encoding if the codec allows to do it.
    Re-encoding means loss of quality and a very lengthy process.
    QuickTime format is great as long as the "final customer" can read it. For example, set-top boxes can usually read DivX AVI and MPEGs, but not QuickTime format.

    The second limitation is related to container format capabilities. While QuickTime can do almost anything, MPEG and AVI cannot handle chapter, resizing or mixing media from several sources. Therefore, for AVI, MPEG, the following actions will be discarded when saving:
    Add Chapters
    Resize or rotate movie
    and finally mixing media from incompatible sources will probably force you to save in QuickTime format.

    A lot of ways to save your work
    File>Save tries to keep same file location and format.
    File>Save As... gives you the choice of location and of format.
    File>Export or Convert is a different way to save a movie. It involves re-encoding the media to the same or to a different codec and format, thus is very slow and involves some quality loss.
    Save RefMovie... is like regular QuickTime format saving, but without "flattening". It means that SimpleMovieX doesn't copy the media data, just the recipe to describe the movie. You can think of it as a kind of playlist where you can specify which chunks of movies are played in sequence. The main advantage is speed and low file size, the main drawback is fragility as if you move or delete any of the referenced media data, the RefMovie can be lost.



    Native Editing
    Native Formats

    We call Native the formats that SimpleMovieX can read, edit and save.
    SimpleMovieX can also read and edit more formats, actually all the formats supported by QuickTime and codecs installed in the system. However, saving is restricted to the following ones:

    QuickTime .mov
    MPEG-1 and MPEG-2 (more info)
    Microsoft .avi
    MPEG-4


    Native vs Transcoding

    SimpleMovieX also leverages the exporter components compatible with QuickTime to make transcoding of format possible. For example, a DV clip can be converted to MPEG-4 through the Export menu.
    Transcoding is not as good as Native editing, because it is about 10 times slower to perform and some quality is lost. If you have a 5 minutes DivX .avi clip, you can either save it natively in avi format, which will take a dozen of seconds, or transcode it with DivX avi exporter, which will take 5 minutes and erode the image quality.

    QuickTime .mov

    No restriction. Any file that SimpleMovieX is able to open, can be edited and saved in .mov format. Movie is saved as it is in the editor window.

    MPEG-1 and MPEG-2

    Editing is possible as long as files are homogenous, i.e. they share the same audio and video encoding, bitrate and pixel size. It means that cutting and pasting is not only possible within a document, but also between separate files.

    The main restriction is about editing accuracy : If the document is saved in .mov format, frame accurate editing is permitted. However, if you save in MPEG format, editing points are rounded to the nearest keyframe (Group of Picture), which means that accuracy is around 15 frames. SimpleMovieX v3.0 features a keyframe indicator and a sticky mode to help you.

    The last restriction is relative to MPEG-2, and comes from Apple's component : Only mp2 audio codec is supported, not AC3 (a52, Dolby not supported). See also MPEG support.

    Main advantages with respect to QuickTime Pro are, besides editing and native saving capabilities :

    Audio transcoding. You can convert MPEG files without loosing audio.
    Support for files beyond 4GB.

    MPEG-4

    No restriction as long as the movies involved have the same pixel size. Movie is saved as it is in the editor window, but chapters are lost.

    Any movie (any format or container) can be saved as MPEG-4 if its video codec is H264/AVC1 or MPEG-4 Video and its audio is AAC.

    AVI

    AVI files contain in general one DivX or 3vix video track and one mp3 audio track. SimpleMovieX supports any video codec that QuickTime understands (this includes DivX and 3vix if you install the respective codecs) and the following audio codecs:

    raw, integer, a-law, mu-law, AAC, AC-3 (A52 Dobly, 5 channels), MP2, MP3, DVI ADPCM.

    Other audio formats are not supported at this stage. This is why an .avi file containing an Ogg Vorbis sound track cannot be saved as .avi, even untouched.

    Several files can be edited and mixed if they share the same homogenous video and audio codecs, bitrates and pixel size. If you save in native AVI format, editing points are rounded to the nearest keyframe. SimpleMovieX features a keyframe indicator and a sticky mode to help you.

    Main advantages with respect to QuickTime Pro, besides native saving capability, are support for OpenDML and for big files beyond 1, 2, and even 4 GB. (QT Pro would truncate them).
  13. #13  
    yili3952's Avatar
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    Default Re: Demux

    Video Converter does it well and you can queue up a bunch of AVI files and choose the output format (.mp4) to convert them.
    Take a look at this avi to mp4 mac guide: How to Convert AVI Files to MP4 (or Vice Versa) on Mac

    Also, The device presets work fine to view the converted videos on the iPads & other Apple products.

    Regards
  14. Thread AuthorThread Author   #14  
    espr3ss0's Avatar
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    Default Re: Demux

    Is anyone familiar with VLC ?

    I tried Simple Movie x but it costs ;-p
  15. Thread AuthorThread Author   #15  
    espr3ss0's Avatar
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    Default Re: Demux

    I've gone all out to install FFMPEG :-) and so far everything has been done ok. But !, with "copy" for Audio & Video from the 'container' the .AVI file to a new .MP4 file, which worked ok but might have a header problem of some sorts, playing the new .MP4 in VLC works 100% fine however QuickTime plays very jumpy.

    Is there any way to fix this ??

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