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• How do I connect two GIFs to play one after another in Python ?

  9 novembre 2022, par Andrew

  If I have two GIFs, GIF 1 being 10 seconds long and GIF 2 being 5 seconds long, is there a way to connect them so the final GIF is a total of 15 seconds long ?

  


  Would I have to loop through each frame of both the GIFs with imageio.mimread() and output, once all the frames are read in memory ?

  


  Or is there another way by knowing the start and end times and shifting it ?

  


  Edit :
The solution presented by FirefoxMetzger is extremely Pythonic, ideal if you do not wish to install other software / packages like gifsicle.

  


  import imageio.v3 as iio
import numpy as np

frames = np.vstack([
    iio.imread("imageio1.gif"),
    iio.imread("imageio2.gif"),
])

# get duration each frame is displayed
iio.imwrite("imageio_combined.gif", frames)


  


  This completes in 15.6 seconds for two GIFs, each containing 100 frames.

  


  However, if runtime is important, I recommend gifsicle :

  


  gifsicle(
    sources=["imageio1.gif", "imageio2.gif"], # or just omit it and will use the first source provided.
    destination="imageio3.gif",
    options=["--optimize=2", "--threads=2", "--no-conserve-memory"]
)


  


  This completes in 4.8 seconds, which is three times as fast.

  


• Run ffmpeg once but get multiple screenshots

  9 novembre 2017, par user779159

  I get a screenshot from a remote video file using ffmpeg with a command like ffmpeg -ss $TIME -i $URL -frames:v 1 -filter:v $FILTER file.jpg (-ss comes before -i for fast seeking https://trac.ffmpeg.org/wiki/Seeking). $FILTER is how I want to transform the screenshot, like cropping/resizing. In this case it’s "crop=iw-5:ih-5, scale=100:100:force_original_aspect_ratio=increase, crop=100:100")

  If I want to get 3 screenshots, at 3 seconds, 5 seconds, and 14 seconds, I need to run this command 3 separate times, passing 3, 5, and 14 as $TIME. But is it possible to run the command once but have it output multiple screenshot files for the different times ?

  And would ffmpeg do that in a way where it would make the round-trip remote request just 1 time instead of 3 ? In that case it would be more efficient. If not, then maybe it’s better to make the 3 requests separately since I could do it in parallel.

• How to generate only 10 thumbnails irrespective of video duration with ffmpeg

  15 août 2022, par EaBengaluru

  Hi i want to generate only 10 thumbnails irrespective of video duration with ffmpeg

  


  I have followed this thread Create multiple thumbnails from a video at equal times / intervals

  


  here is the command i'm using

  


  ffmpeg -i input.mp4 -vf "select='not(mod(t,60/12))'" -vsync vfr output_%04d.jpg


  


  for 14.4 duration video it is generating only 3 thumbnails , i want always 10 with equal interval.

  


  For example if i have 120 duration video i must get thumbnails at

  


  [0 or 12, 24,36,48,60,72,84,96,108,120]


  


  Question : i want to generate always 10 thumbnails with equal interval as shown in example for duration of 120