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• Generating movie from python without saving individual frames to files

  8 avril 2015, par Paul

  I would like to create an h264 or divx movie from frames that I generate in a python script in matplotlib. There are about 100k frames in this movie.

  In examples on the web [eg. 1], I have only seen the method of saving each frame as a png and then running mencoder or ffmpeg on these files. In my case, saving each frame is impractical. Is there a way to take a plot generated from matplotlib and pipe it directly to ffmpeg, generating no intermediate files ?

  Programming with ffmpeg’s C-api is too difficult for me [eg. 2]. Also, I need an encoding that has good compression such as x264 as the movie file will otherwise be too large for a subsequent step. So it would be great to stick with mencoder/ffmpeg/x264.

  Is there something that can be done with pipes [3] ?

  [1] http://matplotlib.sourceforge.net/examples/animation/movie_demo.html

  [2] http://stackoverflow.com/questions/2940671

  [3] http://www.ffmpeg.org/ffmpeg-doc.html#SEC41

• ffmpeg - convert video into individual frame image files ? [closed]

  2 janvier 2021, par MrFunreal

  i am trying to turn every single frame of a video file into png files using ffmpeg.
i have found several guides on how to do that, most of which look the same, by doing this :

  


  


  ffmpeg -i vid.mp4 frames/out%03d.png

  


  


  However, this does not work. FFmpeg for some reason just replaces the "%0" of the output file with the entire path of the bat file and then tells me that's wrong, like so :

  


  


  [image2 @ 000002c6aa87f680] Could not open file :
frames/outG :\Videos\vid_to_frames\3_video_to_frames.bat3d.jpg
av_interleaved_write_frame() : I/O error

  


  


  If i remove the "%0" of the output file it creates a single frame and gives me an error, telling me i need to put the "%03d" into the name, which doesn't work.

  


  


  [image2 @ 000001dc9a09fd40] Could not get frame filename number 2 from
pattern '$filename3d.png'. Use '-frames:v 1' for a single image, or
'-update' option, or use a pattern such as %03d within the filename.
av_interleaved_write_frame() : Invalid argument

  


  


  Is this just broken ?
I found about 20 guides on how to do it, all of which use this exact same method and it just doesn't work.

  


  Does anyone know another way to do this via ffmpeg ? (it must be via ffmpeg)

  


• FFmpeg individual image zoom-in transition

  19 juillet 2024, par The Somebody

  I'm stuck with an ffmpeg command that needs to generate a video. Originally, I had an ffmpeg command that would loop through images and change after a certain amount of time. Now, to improve the video a little bit, I wish to add a zoom in effect on each image.

  


  I am facing an issue that when I generate the video, the images no longer change. That is, it is constantly first image. I can the zoom effect replay as it should (for every changing image), but the images do not actually change (it is always the first picture). Any advice/suggestion would be appreciated. I am sure, it will be something wrong with the syntax, but now I am at a loss..

  


  Original code, that works fine (without the zoom in) :

  


  ffmpeg -n -loop 1 -t 26.01 -i "\image_0.png" -loop 1 -t 26.01 -i "\image_1.png"
 -loop 1 -t 26.01 -i "\image_2.png" -loop 1 -t 26.01 -i "\image_3.png" 
 -i "/speech.mp3" 
 -filter_complex "[0:v]scale=1080x1920,setpts=PTS-STARTPTS[v0]; 
 [1:v]scale=1080x1920,setpts=PTS-STARTPTS[v1]; 
 [2:v]scale=1080x1920,setpts=PTS-STARTPTS[v2]; 
 [3:v]scale=1080x1920,setpts=PTS-STARTPTS[v3]; 
 [v0][v1][v2][v3]concat=n=4:v=1:a=0,subtitles='"C\:/transcription.ass"'[v]" -map "[v]" -map 4:a -c:v libx264 -c:a aac -b:a 192k
 -shortest "C:\Videos/Video.mp4" -loglevel verbose


  


  Code that does not work as intended :

  


  ffmpeg -n -loop 1 -t 26.01 -i "\image_0.png" -loop 1 -t 26.01 -i "\image_1.png" -loop 1 -t 26.01 -i "\image_2.png" -loop 1 -t 26.01 -i "\image_3.png" -i "/speech.mp3" -filter_complex "[0:v]scale=1080x1920,zoompan=z='zoom+0.001':d=650:s=1080x1920:x=iw/2-(iw/zoom/2):y=ih/2-(ih/zoom/2),setpts=PTS-STARTPTS[v0]; [1:v]scale=1080x1920,zoompan=z='zoom+0.001':d=650:s=1080x1920:x=iw/2-(iw/zoom/2):y=ih/2-(ih/zoom/2),setpts=PTS-STARTPTS[v1]; [2:v]scale=1080x1920,zoompan=z='zoom+0.001':d=650:s=1080x1920:x=iw/2-(iw/zoom/2):y=ih/2-(ih/zoom/2),setpts=PTS-STARTPTS[v2]; [1:v]scale=1080x1920,zoompan='z=zoom+0.001':d=650:s=1080x1920:x=iw/2-(iw/zoom/2):y=ih/2-(ih/zoom/2),setpts=PTS-STARTPTS[v3]; [v0][v1][v2][v3]concat=n=4:v=1:a=0,subtitles='C\:/transcription.ass'[v]" -map "[v]" -map 4:a -c:v libx264 -c:a aac -b:a 192k -shortest "C:\Videos/Video.mp4" -loglevel verbose


  


  I tried to change and see if it really is just the first image that's used through out the video and confirmed it. Also tried to play around with the symbols '"', ' ' ', etc.