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• Matplotlib can not save animation

  1er avril 2020, par Justin Furuness

  I have a matplotlib animation and it will not save. If I do not save it, it runs totally fine and without error. When I try to save it errors with a message that is not helpful. I have googled this error and checked everything, but I cannot seem to find an answer to this problem. I have installed ffmpeg. Am I doing something wrong that is obvious ? I am running on ubuntu 19.10 with matplotlib 3.2.1 if that matters.

  



  The code to save the animation is below :

  



      def run_animation(self, total_rounds):
        anim = animation.FuncAnimation(self.fig, self.animate,
                                       init_func=self.init,
                                       frames=total_rounds * 100,
                                       interval=40,
                                       blit=True)
#        Writer = animation.writers['ffmpeg']
#        writer = Writer(fps=15, metadata=dict(artist='Me'), bitrate=1800)
        anim.save('animation.mp4')


  



  The error traceback :

  



  2020-04-01 02:20:58,279-INFO: MovieWriter._run: running command: ffmpeg -f rawvideo -vcodec rawvideo -s 1200x500 -pix_fmt rgba -r 25.0 -loglevel error -i pipe: -vcodec h264 -pix_fmt yuv420p -y animation.mp4
Traceback (most recent call last):
  File "/home/anon/.local/lib/python3.7/site-packages/matplotlib/backend_bases.py", line 2785, in _wait_cursor_for_draw_cm
    self.set_cursor(cursors.WAIT)
  File "/home/anon/.local/lib/python3.7/site-packages/matplotlib/backends/backend_gtk3.py", line 468, in set_cursor
    self.canvas.get_property("window").set_cursor(cursord[cursor])
AttributeError: 'NoneType' object has no attribute 'set_cursor'


  



  Thanks a million for your help

  


• ffplay -noborder option missing argument

  10 janvier 2021, par Tomás Arturo Herrera Castro

  If I do :

  


  ffplay -i vid.mp4


  


  ffplay works fine, however if I try the borderless option :

  


  ffplay -noborder -i vid.mp4

Failed to set value '-i' for option 'noborder': Option not found


  


  Trying the -noborder option at the end of the command :

  


  ffplay -i vid.mp4 -noborder

Missing argument for option 'noborder'


  


  Any clue on the argument -noborder is waiting for or why isn't this working ?

  


  This is the ffplay version I am using :

  


  ffplay version 2.8.17-0ubuntu0.1 Copyright (c) 2003-2020 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.12) 20160609
  configuration: --prefix=/usr --extra-version=0ubuntu0.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv


  


• Ffmpeg inaccurate cut duration with ts [duplicate]

  30 juillet 2020, par Lemon Sky

  I need to accurately seek and cut a video. Some online sources say put -ss in front or after the source. The result is the same for me. In the examples below, the start time is accurate but the duration is not accurate.

  


  ffmpeg -y -ss 00:00:05 -t 00:00:05 -i http://tyberis.com/output.ts 5s.wav
ffprobe 5s.wav

Duration: 00:00:04.74

ffmpeg -y -i http://tyberis.com/output.ts -ss 00:00:05 -t 00:00:05 5s.wav
ffprobe 5s.wav

Duration: 00:00:04.74


  


  Sometimes the starting point is not accurate but the duration is. This is clearly audible by cutting the ts file and cutting an uncompressed wav file, and listening to both.

  


  ffmpeg -y -i http://tyberis.com/output.ts -ss 00:00:15 -t 00:00:05 5s.wav

ffmpeg -y -i http://tyberis.com/output.wav -ss 00:00:15 -t 00:00:05 5s-reference.wav


  


  What fixes the starting time is if I use an m3u8 file that contains the byte offset for every keyframe AND I put the -ss option in front of the source file (if I put it after the source, the start time is inaccurate but the duration is accurate) :

  


  ffmpeg -y -ss 00:00:15 -t 00:00:05 -i http://tyberis.com/output.m3u8 5s.wav


  


  This fixes the start time but the duration is at the location that I would get had I used no m3u8 file (duration is just 4.47s).

  


  It seems different timestamps are involved, and sometimes one or the other gets used.

  


  The ts file was generated by capturing a UDP stream and storing it with ffmpeg and -codec:v copy.

  


  Is ffmpeg broken, or the ts file ? How do I work around this issue or fix the ts file ? What I realize is that the video starts later than the audio, probably because the video does not start with a keyframe. Can I get ffmpeg to start the -codec:v copy after the first keyframe ? What I also notice is that using ffprobe reports "start : 1.400000". Can I force it to start at 0 ?

  


  Any hints would be appreciated.

  


  I tried both ffmpeg 4.3.1 and ffmpeg git-2020-07-24-21442a8.