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• ffmpeg mp4 shows blurred frames after seeking in the video with internet explorer

  21 février 2014, par Larzzz

  I have a question regarding JWPlayer 5, IE and video encoding.
  Basicly I use a Wowza server to stream my files. This works on all devices (windows, iOS and Android).
  However when i play it in Internet Explorer, it behaves strange.
  It plays fine, and the entire movie looks good without any issues. But when I seek in the video, it shows a line in the center of my video, like if the previous frame is still showing some part, and it refreshes after a few frames move in the video.
  The frames itself are not broken, as if i just play the video without seeking it all looks good.
  This does not happen in Chrome, Firefox or Safari, neither does this happen on android & iOS.
  I've tested this with JW 6 as well, and it shows the same results for IE.

  Altough it's showing fine on other browsers, I still believe it's an issue with encoding, as other videos do not show this behavior.

  Example viewable here : http://www.mobileevolution.be/standardcode-withsmil.html

  The FFMPEG code i use to convert any file (.avi in this case) to an MP4 :

  "ffmpeg.exe" -i "%1" -vcodec libx264 -strict experimental -c:a aac -profile:v baseline -level 3 -movflags faststart -bufsize 1000k -tune zerolatency -b:v 1000k -minrate 600k -maxrate 1500k "%5%71000k.mp4"

  the %1, %5 and %7 are variables i send with a script.

  I have tried various options, but could not figure out what the problem is.
  I have also tried converting with handbrake, but this shows similar results.

  My questions are :
  Has anyone seen this before ?
  Does anyone know a solution ?
  What's wrong with my FFMPEG settings ?

  Thanks for any help,
  Grts

  EDIT
  pictures :
  http://www.mobileevolution.be/foto1.jpg
  http://www.mobileevolution.be/foto2.jpg
  console output :
  http://www.mobileevolution.be/consoleoutput.txt

• 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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• Revision 6ce718eb18 : Merge "End of orientation zero group experiment" into experimental

  22 avril 2013, par Deb Mukherjee

  Changed Paths : Modify /vp9/decoder/vp9_decodframe.c Modify /vp9/encoder/vp9_encodemb.c Modify /vp9/encoder/vp9_rdopt.c Merge "End of orientation zero group experiment" into experimental