iMovie Exporting .mov or .m4v?

Discussion in 'Digital Video' started by WhyIs TJ SoCool, Dec 28, 2008.

  1. WhyIs TJ SoCool macrumors newbie

    Joined:
    Jul 1, 2008
    #1
    Hi all,

    I'm hoping somebody would be able to provide a good explanation on why .mov files are so much larger than .m4v files when you export your videos from iMovie and which file is more universal (ie. will i have a hard time finding players that support .m4v).

    Example, I put together a video that's 52.32 minutes long of a family trip to Australia.

    The .m4v file is only 1.44 GB
    Dimensions: 960x540
    Codecs: H.264 AAC
    Channel count: 2
    Total bit rate: 3,945

    and the .mov file is 4.86 GB
    Dimensions: 960x540
    Codecs: H.264 Integer (Little Endian)
    Channel count: 2
    Total bit rate: 13,237

    I think that's 'a HUGE difference in file size and I don't notice any quality differences. Is there a way that I can reduce the .mov size to a comparable level without loosing any quality? I want to minimize file size, uphold quality, and save my family videos in a format that will be playable in many different media players.

    EDIT: I forgot to mention that I searched the forms and Google for this topic and only found one relative page talking about these files as containers. That whole explantation to me seemed to miss the point of the other poster's question so if it's possible to avoid the whole "container discussion", that would be great.

    THanks,

    -TJ
     
  2. DPA macrumors 65816

    DPA

    #2
    The reason .mov (Quicktime Movie) files are so much larger than .mp4 (MPEG-4) files are because when converted to MPEG-4 the video is compressed. You may also notice that an .mp4 file is smaller (lower resolution) and when you try to make the image larger is pixelates. When you compress something, you are making the file size smaller and/or a different file type. If you want your video a high resolution then keep it .mov. If you want it to be smaller for a DVD or USB drive (for transport) then make it .mp4 if possible. Hope I could help you understand better.:)
     
  3. -DH macrumors 65816

    Joined:
    Nov 28, 2006
    Location:
    Nashville Tennessee
    #3
    The first thing to consider is 'what will be your delivery format?" If it's going to be web delivery, then Flash will provide the highest playback compatibility. But if you want to delever via a specialty site such as Youtube or Vimeo, they'll each have their own recommendations.

    If it's going to be DVD-Video, then exporting a QuickTime Movie (self-contained or reference) is what you'll need for authoring in iDVD or DVD-SP. You do NOT want to use MPEG-4 because you'll only be adding more compression to the video.

    If it's for DVD-ROM (data) delivery, then MPEG-4 would be fine.

    If you intend to have multiple delivery types (web, DVD-Video, iPod, etc), it is best to create a separate file of the appropriate type for each delivery method.

    -DH
     
  4. DPA macrumors 65816

    DPA

    #4
    Thank you -DH, I didn't mention the different uses and what is best for each. If you put your video up on YouTube or Vimeo then I would suggest a .mov file. YouTube only offers three types of video resolution, normal, high and HD. Vimeo offers SD and HD. So if you upload it in HD then it will, eventually, have a higher quality option. The quality of a Flash encoded video depends on what codecs you put the video through. Codecs, here, are basically types of compression. I believe there are hundreds in Flash. If you've heard of H.264, that's a codec. The more codecs you put your video through, usually the faster it streams, the smaller the file and the lesser the quality. Thats the reason higher quality video (high and HD) on YouTube streams (loads) slower.
     
  5. -DH macrumors 65816

    Joined:
    Nov 28, 2006
    Location:
    Nashville Tennessee
    #5
    The QuickTime .mov file type designation is only a container that could be made from any number of codecs. The same is true of the .avi file type. Both Youtube and Vimeo ( and most other sharing sites) automatically convert every video to Flash.

    Partially correct. A Codec is a compression & decompression scheme. It defines both how the file is compressed AND decompressed for playback.

    You do NOT want to compress the video any more times than is needed to get to your destination. Each compression will take it's toll on quality.

    -DH
     
  6. DPA macrumors 65816

    DPA

    #6
    I basically was on a time crunch and that is why I didn't fully explain what a codec is, I didn't want him to be misinformed so I included the Wikipedia page which explains what a codec is in more depth than I can explain. Once again, because of time I had to shorten, I didn't get to say that most sharing site convert to Flash. I tried to get at that you did not want to compress any more than necessary by saying it reduces the quality. If anybody who read my previous post did not understand I'm sorry, -DH has replied and posted a nice reply explaining with some more detail and explanation.:) The compression vs. quality issue is mainly the reason why some videos on the web have high speed/T1 and broadband/DSL connection choices for viewing videos options.
     
  7. Courtaj macrumors 6502a

    Courtaj

    Joined:
    Jul 3, 2008
    Location:
    Edinburgh, U.K.
    #7
    Shut. Up. I mean that in a nice way. Would you like more detail and explanation?
     
  8. DPA macrumors 65816

    DPA

    #8
    I didn't think anybody meant anything in a mean way if that's what you mean. I just was thanking -DH you giving a better explanation then me. And if you think I sound a little weird like too nice or something I guess you are right I do sound a little bit like kindergarten teacher trying to get the kindergartners to use manners. HAHA.
     
  9. WhyIs TJ SoCool thread starter macrumors newbie

    Joined:
    Jul 1, 2008
    #9
    Thank you to all who have responded; I appreciate the assist. I don't recall seeing any difference in quality between the two videos but perhaps I need to hook my laptop up to my TV and sample the two again. If not I think I may just stick with the MPEG-4 to save room.
     
  10. DPA macrumors 65816

    DPA

    #10
    You might as well just stay with the MPEG-4 if there is not much resolution and quality loss. The reason you aren't seeing a difference may be because you saved it as a reference movie (does iMovie have the self-contained/reference option) which basically looks off of the files you have saved on your hard drive. You possibly will notice a bigger difference if you saved it as a self-contained movie. I don't know if iMovie gives you that option though, I think it may just automatically save it as a self-contained movie. That would make more sense.
     

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