Sur d’autres sites (12739)

• create video editor error stream specifier [on hold]

  25 mai 2018, par Oussama

  I am a beginner in ffmpeg, and I started by creating a video editor, but I encountered an error while executing an ffmpeg command :

  ’Stream specifier’ ’ in filtergraph description .... matches no streams’

  Here is the command :

  ’ffmpeg -y -i icone1.jpg -i icone2.jpg -i icone3.jpg -i icone4.jpg -loop 1 -framerate 24 -t 5 -i image1.jpg -loop 1 -framerate 24 -t 5 -i image2.jpg -i song.mp3 -filter_complex " color=black@0:1365x701,format=yuva444p[c0] ; color=black@0:1365x701,format=yuva444p[c1] ; [c0][4]scale2ref[ct0][mv0] ; [c1][5]scale2ref[ct1][mv1] ; [ct0]setsar=1,split=2[t00][t01] ; [ct1]setsar=1,split=1[t10] ; [t00]drawtext=fontfile=’arial’:text=’azaazzaza’:fontcolor=red:fontsize=30[tfi00] ; [t01]drawtext=fontfile=’arial’:text=’drtgfh’:fontcolor=red:fontsize=30[tfi01] ; [t10]drawtext=fontfile=’arial’:text=’uygfdsdsqds’:fontcolor=blue:fontsize=30[tfi10] ; [mv0][tfi00]overlay=x=55.0000:y=12.0000:shortest=1[mv0] ; [mv0][tfi01]overlay=x=55.0000:y=12.0000:shortest=1[mv0] ; [mv1][tfi10]overlay=x=55.0000:y=55.0000:shortest=1[mv1] ; [0]scale=500:500,setsar=sar=1[img0] ; [1]scale=500:500,setsar=sar=1[img1] ; [2]scale=40:50,setsar=sar=1[img2] ; [3]scale=500:500,setsar=sar=1[img3] ; [mv0][img0]overlay=20.0000:20.0000[mv01] ; [mv01][img1]overlay=12.0000:12.0000[mv02] ; [mv1][img2]overlay=20.0000:12.0000[mv12] ; [mv12][img3]overlay=55.0000:12.0000[mv13] ; [mv02]scale=1280:720,setsar=sar=1[fram0] ; [mv13]scale=1280:720,setsar=sar=1[fram1] ; [5]atrim=duration=10[a1] ; [fram0][fram1]concat=n=2:v=1:a=0[all]" -map [all] -map [a1] video-8.mp4’

• How do I properly save an animation involving circles with matplotlib.animation and ffmpeg ?

  12 juillet 2020, par bghost

  I recently tried out matplotlib.animation, and it's a wonderful tool. I can now make and save basic animations (ie that only involve straight lines) without any issues. However, when I made an animation involving circles, even though the interactive display was perfect, the saved mp4 file wasn't really satisfying. In the mp4 file, the edges of the circles were blurred, and if the circles were made semi-transparent (ie with an alpha value < 1), they all suddenly became completely opaque after a couple of frames. I suspected it was due to the fact that my bitrate wasn't high enough, but I went up to 10000 kb/s (instead of 1800), and exactly the same phenomenon occurred.

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  What can be done to solve these 2 issues (blurred edges + negated transparency) in the generated mp4 file ?

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  Here is a simple animation that describes what I just said :

  &#xA;

  import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation

fig = plt.figure(figsize=(11, 7))
ax = plt.axes(xlim=(-1.2, 1.2), ylim=(-0.7, 0.7))
ax.set_aspect('equal')

dict_circles = {}
dict_circles['ring'] = plt.Circle((-0.5, 0), 0.5, color='b', lw=2, fill=False)
dict_circles['disk'] = plt.Circle((-0.5, 0), 0.5, color='b', alpha=0.2)

def init():
    for circle in dict_circles.values():
        ax.add_patch(circle)
    return(dict_circles.values())

nb_frames = 100
X_center = np.linspace(-0.5, 0.5, nb_frames)

def animate(frame):
    for circle in dict_circles.values():
        circle.center = (X_center[frame], 0)
        ax.add_patch(circle)
    return(dict_circles.values())

ani = animation.FuncAnimation(fig, animate, init_func=init, frames=nb_frames, blit=True, interval=10, repeat=False)
plt.show()

plt.rcParams['animation.ffmpeg_path'] = 'C:\\ffmpeg\\bin\\ffmpeg.exe'
Writer = animation.writers['ffmpeg']
writer_ref = Writer(fps=15, bitrate=1800)

ani.save('Blue circle.mp4', writer=writer_ref)


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• FFMPEG, Blur an area of a video using Image Select Areas Plugin

  12 juillet 2016, par Drupalist

  I am building an online video editor. I need to allow the users to blur an area of movies. This must be done graphically, I mean user should be able to select an area of a video, using an screenshot, then the selected area must be blurred. Some thing like this

  

  Is there anyway to map this selected area dimension and its distance from borders to the real values that must be applied to the video ?

  I mean four numbers, width, length, top, left will be provided using this plug in and I need to use these numbers to blur an area of videos.

  I take an screenshot of video. In order to keep the aspect ratio, I will fix the width to 800px and let the height to be scaled up/down. It is clear that the width, length, top, left of the selected area of the screenshot is a factor of the width, length, top, left of the area that must be blurred in video. but I don’t know how to get this factor. Besides that I don’t know how to get the video resolution.

  Thanks in advance.

  ---

  Update

  This is my PHP code that gets the selected area dimensions and offsets

  $iLeft = $_POST['left'];
  
  $iTop = $_POST['top'];
  
  $iWidth = $_POST['width'];
  
  $iHeight = $_POST['height'];
  
  exec('ffmpeg -i '.$url.' -filter_complex "[0:v]scale=iw*sar:ih,setsar=1,split[bg][bb];[bb]crop='.$iWidth.'*iw/800:iw*'.$iHeight.'/800:'.$iWidth.'*iw/800:'.$iHeight.'*iw/800,boxblur=10[b0];[bg][b0]overlay='.$iLeft.'*W/800:'.$iTop.'*W/800"" '.$name.' > block.txt 2>&1');

  $iLeft, $iTop, $iWidth, $iHeight are the left, top, width and height of the selected area via the image plugin.

  It blurs many selected areas very well, but areas like this

  

  The Image Left, Top, Width, Height is 257,  39.26666259765625,  10,  391

  don’t get blurred. Also a video with Dimension 207x207 didn’t get blurred as well.