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Mp4 to raw video...

  1. Jul 28, 2018 #1
    Hello everyone,

    Does anyone know if it is possible to convert a mp4 video clip to raw video? Or once the video is in mp4 format or any other format there is no way to go back to raw?

    Do certain cameras allows to shoot the video so that both types of files can be saved at the same time?

    Thank you!
     
  2. jcsd
  3. Jul 28, 2018 #2

    Stephen Tashi

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    What file format do you consider to be "raw" video?
     
  4. Jul 28, 2018 #3
    Well, I know that certain cameras can be set to RAW to just capture information without adding anything to it. The mp4 format seems to be slightly edited.

    I think canon has a setting called RAW in the quality settings...
     
  5. Jul 28, 2018 #4

    Stephen Tashi

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    You need to look at the file your camera produces and determine its format.

    My video camera produces files in the "Quicktime" (*.MOV) format.

    There are programs to convert mp4 files to Quicktime.

    If a video is taken in Quicktime or other format and converted to mp4 format, information may be lost. This depends on the settings used to make the conversion. For example, the name mp4 does not specify that the video must have a particular resolution in pixels. If video file is converted to a lower resolution mp4 file, you cannot recreate the original video by reversing the conversion.

    For example, videos of old films and TV shows downloaded from YouTube are often in the mp4 or webm format. They are usually highly compressed versions of the information in the original video, so they have less resolution in pixels and lower frame rates that the original.
     
  6. Jul 28, 2018 #5
    The RAW setting on Canon camera is for images, it cannot be used for video (it would use way too much bandwidth and storage space). For video you have the option of using Quicktime MOV or MP4 however both are container file formats and can use different encoding algorithms not to speak of different settings. One of the options on the Canon cameras (MOV or MP4) results in slightly higher quality but I don't remember which.
     
  7. Jul 28, 2018 #6
    I see. Thank you.
    I was wondering if it was possible to shoot video, with a camera, in raw format, as I often hear, in order to have the maximum flexibility later as far as editing goes.
     
  8. Jul 28, 2018 #7
    The answer to that is yes or no depending on the specific camera you are using.
     
  9. Jul 30, 2018 #8
    What parameter mainly determines the quality of the video? The sample rate? I am thinking that the higher the sample rate, the more information are captured, the higher the details hence the higher the video quality.
     
  10. Aug 1, 2018 #9
    I would like to point out that ".mov" is not a video format, it's just a container. It's basically the same idea as a zip file or a tarball that can have stuff inside of it an a variety of format, plus a manifest that says how to play them. There is no MOV codec, so if you're camera saves things as mov, it's still likely compressing it to mp4 or mpeg2.
     
  11. Aug 1, 2018 #10

    russ_watters

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    Staff: Mentor

    Sampling rate is a parameter for compression. RAW means raw; no compression.

    The size of an uncompressed image file is a simple function of the number of pixels and their bit depth(number of available colors). Then video has a number of frames per second.

    So, for example, if a camera shoots 4K (3840×2160) video and has a color depth of 12 bits per pixel and a framerates of 30 fps, that's 3840x2160x12x30= 3 billion bits per second or 355 megabytes per second.

    Now, I do have an astronomy camera that can transmit uncompressed video directly to a computer, but the resolution is low.
     
    Last edited: Aug 1, 2018
  12. Aug 1, 2018 #11
    Out of curiosity, are you sure it’s sending raw data? I see no reason why it would do that as there are ways to send compressed but lossless data. I feel like it’s be cheaper computationally to do a lossless compression then do the socket transfer, rather than trying to shove raw pixels through what Id assume is a TCP socket.
     
  13. Aug 5, 2018 #12

    russ_watters

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    I guess I can't be certain what is going on under the hood, but the codec the camera uses by default is y800, which is uncompressed, not lossless. I guess my thought was that computationally it is easier to do no processing and just read, then send the raw data through the USB interface. Here's the camera, if you are interested in looking further into it:
    https://www.theimagingsource.com/products/industrial-cameras/usb-2.0-monochrome/dmk31au03/
     
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