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• FFMPEG and Matplotlib for animations - strange outputs ?

  27 juin 2020, par user13132640

  I'm trying to create animations using FFMPEG and matplotlib. Using the below code, I am creating the FFMpeg writer, and then using a loop, writing a series of graphs to the animation. However, the outputs I'm getting are very strange ; sometimes, when I watch the .mp4 file, the first 5 seconds are blank, then the video "ends" (the playback time on my media player says that it's complete), and at that point, my animation shows up. Other times, some frames are missing or skipped. I've tried searching around, but frankly I haven't found anyone with similar issues.

  


  I just installed the latest version of FFMpeg today.

  


  FFMpegWriter = manimation.writers['ffmpeg']
metadata = dict(title='Animation test', artist='name')
writer = FFMpegWriter(fps=1, metadata=metadata) # 1 frames per second, each year is 1 second


  


  Then, the plotting part...(I've excluded the code where I setup the fig, ax etc.)

  


  with writer.saving(fig, "animation.mp4", dpi=200):
    year = "2005"
    for i in range(4):

        d1_plot = d1[d1['Year'].str.contains(year, na=False)]
        ax.scatter(d1_plot["Lat"], d1_plot["Long"], c='g', s=d1_plot["Size"], transform=ccrs.PlateCarree())
        ax.set_title(year)
        writer.grab_frame()
        year = str(int(year)+1)


  


• ffmpeg:Unable to broadcast to live stream from webcam

  13 mai 2020, par gbenga ogunbule

  I have this code that I believe should be able to grab from webcam and broadcast a live stream i.e. Users will be able to watch or stream live what there admin is doing at that moment in time.

  



  I have this code for it

  



  C:\Apache24\htdocs\v­ideo\assets\ffmpeg\b­in>ffmpeg -f dshow -i video="HP Webcam" -c:v libx264 -preset ultrafast -tune zerolatency -r 10 -async 1 -c:a libmp3lame -b:a 24k -ar 22050 -bsf:v h264_mp4toannexb -maxrate 750k -bufsize 3000k -f mpegt s C:\Apache24\htdocs\v­ideo\assets\uploads\­videos\en.mp4


  



  Also notice I use the absolute path mpegt s C:\Apache24\htdocs\v­ideo\assets\uploads\­videos\en.mp4 instead localhost/video/assets/uploads/videos/en.mp4 and the reason is because, when I use the latter, it is recording the video into the folder where I run the command.

  



  And this is the HTML code I wrote for it.

  



  <video width="320" height="240" controls="controls">&#xA;  <source src="assets/uploads/videos/en.mp4" type="video/mp4">&#xA;Your browser does not support the video tag.&#xA;</source></video>&#xA;

  



  How do I online streaming using ffmpeg

  


• Concatenating image with video for Freeze frame effect

  12 mai 2015, par Code_Ed_Student

  I am currently trying to achieve with ffmepg a freeze frame effect. This is something easy to do with adobe after effects shown here. However I would like to achieve a freeze frame effect(of 5 seconds duration) followed by the 15 second video for the final output video. This should amount to a final duration of 20 seconds. However with the settings below, I am getting a still image with the video following but it does not show a "freeze frame effect". How can I achieve a "freeze frame effect" in ffmpeg ?

  //create image

  ffmpeg -i "/media/test/test.mp4" -ss 00:00:00.023222 -vframes 1 "/media/test/test.png"

  //create freeze image effect

  ffmpeg -i "/media/test/test.mp4" -loop 1 -i "/media/test/test.jpg" -an \
  
  -filter_complex "[1:v]trim=start=0:end=5[ol];[0:v]setpts=[nv];[nv][ol]overlay=eof_action=pass[final]" \
  
  -map '[final]' -c:a aac -strict experimental -c:v libx264 -q 1 "/media/test/test_effect.mp4"