Recherche avancée

Sur d’autres sites (3547)

• Problem while building libffmpeg.so from ffmpeg sources (undefined symbol : avcodec_version)

  10 octobre 2023, par serggt1

  I'm trying to build libffmpeg.so shared library from sources on Linux. Sources are here FFmpeg.git.

  


  I run

  


  ./configure
make -j4

gcc -shared \
    libavcodec/libavcodec.a \
    libavdevice/libavdevice.a \
    libavfilter/libavfilter.a \
    libavformat/libavformat.a \
    libavutil/libavutil.a \
    libswresample/libswresample.a \
    libswscale/libswscale.a \
    -o libffmpeg.so


  


  The problem is the resulting libffmpeg.so is only 15 KB and says

  


  dlsym fail : /opt/yandex/browser/libffmpeg.so: undefined symbol: avcodec_version


  


  What do I wrong and how to link the library in correct way ?

  


  UPD :

  


  Now trying with this :

  


  ./configure --enable-pic --disable-programs  --enable-gpl --enable-version3 --enable-nonfree

make -j4

ld \
    -rpath-link=/usr/lib \
    -L/usr/lib \
    -L/lib \
    --library=c --library=m --library=z --library=dl --library=log \
    -soname libffmpeg.so -shared -nostdlib -Bsymbolic --whole-archive --no-undefined \
    libavcodec/libavcodec.a \
    libavdevice/libavdevice.a \
    libavfilter/libavfilter.a \
    libavformat/libavformat.a \
    libavutil/libavutil.a \
    libswresample/libswresample.a \
    libswscale/libswscale.a \
    -o libffmpeg.so


  


  Error is ld: cannot find -lc: No such file or directory

  


• Problem to capture a video in 4K with FFmpeg

  16 mars 2020, par Ale7

  I am a new user of FFmpeg. I am trying to capture a ten minutes video in mp4 format, on 4 4K’s slot and 4 FHD’s slot with cards video Pro Capture by Magewell.
  My machine has the following characteristics :

  • OS : Windows Server 2012
  • RAM : 64 GB
  • CPU : 2 processors Intel Xeon E5-2640 v3 @ 2.60 GHz

  The FFmpeg script, for slot 4K (I change resolution for FHD), used is the following :

  ffmpeg -rtbufsize 2048M -re -y -thread_queue_size 20384 -pix_fmt yuv420p -f dshow -video_size 3840x2160 -r 50 -i video="Video (05-0 Pro Capture HDMI 4K+)"  -codec:v libx264  -preset ultrafast -threads 8 -pix_fmt yuv420p -tune fastdecode -bufsize 2048M output.mp4

  This command is the best solution found at the moment, but the CPU goes up to 100% and the buffer fills up quickly and starts to drop the frames.
  So, my question : Is there a way to improve it or is a limit, principally, of the my machine ?
  If it is a machine limit, you would indicate me the minium requirments to do that.

  Thanks in advance to everyone.

• problem with moviepy.video.io.ffmpeg_tools.ffmpeg_movie_from_frames

  7 mars 2023, par fjal

  when i try using this code it gives me this error

  


  from moviepy.video.io.ffmpeg_tools import ffmpeg_movie_from_frames as a
a('file.mp4','New folder',24)


  


  Traceback (most recent call last) :
File "C :\Users\lenovo\Desktop\fr.py", line 2, in 
a('file.mp4','New folder',24)
File "C :\Users\lenovo\AppData\Local\Programs\Python\Python37-32\lib\site-packages\moviepy\video\io\ffmpeg_tools.py", line 20, in ffmpeg_movie_from_frames
"-b", "%dk"%bitrate,
TypeError : %d format : a number is required, not str