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Time Lapse Video using gphoto2 and ffmpeg

August 30th, 2009

An interesting little project I’ve been working on is time lapse photography. I picked up a used Canon Powershot A520 pretty cheap, and set up a laptop with Ubuntu to communicate with the camera. I’m still working on the best angle to minimize the power lines out front, but I’ve got a good start going.

What you’ll need:

  • A Linux machine (a laptop really helps)
  • gphoto2 >= 2.4.5 (note that you can upgrade jaunty’s gphoto2 with the karmic packages to get this version)
  • A camera that supports remote capture
  • An AC power outlet near were you want to take your photos (and an AC adapter for your camera unless you have really awesome batteries).
  • jpeg2yuv and ffmpeg (with libx264 support)
  • Something relatively interesting to take pictures of

This is what I ended up with:

So here’s what I did:

  1. Connect the USB cable to the camera
  2. Run the following command (in a while loop in case it crashes):
    while true ; do
        gphoto2 --capture-and-download -I 30
    done

  3. Wait about 8 hours or so
    1. If you’re impatient like me, you can nfs mount the laptop after about 45 frames (about 20 minutes) and get a preview.
    2. You can rsync the laptop’s nfs mounted directory locally so you don’t have to copy the files over (most likely) wireless every time you want to encode the latest version
  4. Collect all of your images and make sure that each frame is numbered sequentially.
  5. Create an MPEG with jpeg2yuv by piping the output to ffmpeg:
    starframenum=XXXX # put the number of the first image in the sequence here
    jpeg2yuv -b $startframenum \
            -v 0 \
            -j the/path/to/your/images/IMG_%04d.JPG \
            -f 15 \
            -I p | ffmpeg -threads 2 -y -i - \
            -vcodec libx264 \
            -b 2500k \
            -acodec libfaac -ab 48k -ar 48000 -ac 2
            -s 1024x768 -f mp4 \
            outputfile.mp4

  6. In the options above, the important ones are ffmpeg “-f” which is the framerate. You can change this to speed up and or slow down your movie. The “-s” option is the size. Keep in mind that the width and height of your images needs to be a multiple of 16 (ie, 640×480, 1024×768, 1920×1152, etc). Note that 1080 is not divisble by 16. 1280×720 will work for widescreen (16:9) hi-def though. Lastly, the “-b” option is the video encoding bitrate. Increase it for better quality and decrease it for smaller output movie files.

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