WORK IN PROGRESS!!
This web page briefly describes the main steps to create a video of a meteor shower. It does not pretend to be a complete manual but just hints about how to do the main steps to create a video like this one:
ffmpegfrom the terminal:
> ffmpeg -r 24 -f image2 -start_number 2045 -i 0R7A%04d.jpg -vcodec libx264 -crf 25 -pix_fmt yuv420p -vf scale=1620:1080 video.mp4
-r 24: 24 frames per second
-f image2: use static images as source for the video
-start_numer 2045: start at image number 2045 (the first one in my sequence)
-i 0R7A%04d.jpg: the name of the images.
%04dwill be transformed into 0 left padded numbers with 4 digits. So the first image that it will use would be
-vcodec libx264 -crf 25 -pix_fmt yuv420p: Additional codec and format parameters.
-vf scale=1620:1080: Size of the resulting video (near to HD size)
video.mp4: Name of the resulting video
meteors. Take care not selecting other objects like satellites or planes: if it appears in more than 2 frames it is not a meteor. If it appears in 2 frames it might be a meteor. They usually look like a thin line which becomes thinner in its extrems. Some of them might be very faint and small. Comparing the previous frame with the current one is the easiest way to get them. I use Gwenview to blink the files and get them. Yes, this is one of the first hard steps.
File->Open...a frame that does not contain any meteor.
File->Open as Layers...the frames with meteors. If there are many images with meteors (lucky you!!) do not open all the images as your computer may run out of memory. You can do this process grouping your frames. In the
Windows->Dockable Dialogs->Layers)you should see all your frames stacked with the one of the preovious step at the bottom:
eye iconoff in the
Layerspanel, so you will see the first image (the one without meteors):
eye icon) and zoom the meteor to see it clearly.
Right click on layer name->Add layer mask...->White (full opacity). A white square appears right to the layer miniature. Make sure you click on that square (the white border will be on the mask miniature, not the image miniature) as we are going to work in the layer mask, not the layer itself:
Paintbrush toolfrom your
Toolbox. Make sure you use
blackas primary color and an appropiate tool
25respectively might be a good starting point). Just hand draw over your meteor. It should "disappear" letting the below image pixels show. You can show your layer mask with
Right click on layer mask miniature->Show layer mask:
Colors->Invert) and, if necessary, blur the mask a little bit to avoid edge artifacts (
Filters->Blur->Gaussian Blur). Experiment with the parameters and hide the layer mask to see the results
Right click on layer mask miniature->Show layer mask. You show see your original image with the meteor of the second image overlaped. Play with the
eye icon, the
bluruntil you get a good result:
Last update: May 7th, 2019