HD Video Footage...

Discussion in 'MacBook Pro' started by Trialser, May 5, 2009.

  1. Trialser macrumors member

    Joined:
    Sep 25, 2008
    #1
    I recently bought an Aiptek Action HD GVS camera and have some footage on it. I watched it on my non-hd tv and it looked great, but when I put it on my MBP, the quality drops greatly. Dark shots get grainy and outdoor shots look pixelated. Why would this be? Is there a better way to get files off of a SD card then plug in the camera? Or are there settings or programs that allow for better HD playback?
     
  2. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #2
    It's because the SD TV has a lower resolution and the video was downconverted so to speak to be displayed on that TV. By doing that you get only a quarter of the original resolution which seems to be fine when viewed.

    But the original resolution has to be pixelated as the CMOS sensor in that camera is not that big. Look at pictures taken wit a normal point and shot camera in their normal resolution and you will see grain (if low light) and pixels too.

    The smaller the sensor the more pixelated and noisy/grainy (in low light) the footage. That's why Digital SLR cameras have bigger sensors to achieve better image quality and prosumer and professional camcorders have also bigger sensors.

    Also CMOS chips are not the best with video footage, CCDs are better in that regard.


    You also have to take into account that the camera uses the .h264 codec to compress its video footage. .h264 is a lossy and highly compressive codec made for distribution and not footage acquiring.

    I've just looked at sample footage from http://www.megaupload.com/?d=M080FXN4 via http://forums.steves-digicams.com/forums/view_topic.php?id=599934&forum_id=92 and saw that the data rate of the video was 8.26 Mbit/s which is 1.0325 MByte/s for 29.97 frames which results in 35 KByte per picture with 1980x1080 resolution. My digital point and shoot camera with 4000x3000 sized images took 2-4 MByte per picture in JPEG compression, my DSLR takes 5-8 MByte per picture and more when shooting in RAW.

    As the .h264 codec doesn't store every frame, only approximations and changes from one frame to another, you also have loss of quality.

    I hope that much technical information helps.


    PS: a little calculation example.

    The P&S camera takes a picture with 4000*3000 pixels (12000000 pixels as a whole) and creates a 5 MByte picture.
    You camera records a 1920*1080 frame (2073600 pixels as a whole) and takes 35 KByte to store it.

    The 4000*3000 image is 5.78 times bigger than the 1920*1080 frame, but takes up 146.3 times more bytes per pixel than the video frame.

    So the video frame quality is less than 1/25 of the quality of the still image shot with the P&S, and I can still see compression when viewed at 100% in my P&S image.




    PPS: What program are using to edit them if you want to? Does this program read them without problem, or do you have to convert them to something else?
     
  3. Apple Corps macrumors 68020

    Joined:
    Apr 26, 2003
    Location:
    California
    #3
    Let me think - most high quality 1080p HD camcorders sell for $3500 - $10,000 with lens.

    Your unit sells for $250 at a drugstore.

    The one thing I can assure you is that your MacBook Pro

    IS NOT THE PROBLEM
     
  4. Trialser thread starter macrumors member

    Joined:
    Sep 25, 2008
    #4
    Thanks for the input, interesting info. I use Final Cut Pro for editing with my footage from a Panasonic GS300, but when I try to import the HD clips, I get an error. It says unknown file type? So I put them into iMovie HD, and they play smooth and fine, but still not near the quality it should be.
    I know that this camera takes really good quality video, I have seen it on a HDTV. I dont expect the quality of a $3000 cam, but its just no where near what Ive seen from it on a tv.
     
  5. spinnerlys Guest

    spinnerlys

    Joined:
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    forlod bygningen
    #5
    A computer monitor is more brutal to any compressed image than a TV.

    Just look at the sample video in my post above, and you'll see, that the picture quality of the camera is not that much to go with.

    As to the FCP "problem": Panasonic might use a special container format (like .mod, .ts, ....) with the .h264 codec, that is not FCP compatible, as FCP reads professional formats and not every special consumer format the companies can think of.
    And as the video is compressed with .h264, FCP doesn't want it too, as .h264 is not a editing codec.

    You have to convert your video using MPEG Streamclip maybe to something more editable. Consult the manual of FCP for more information.
     

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