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• node-fluent-ffmpeg doesn't resize videos correctly when given specific size

  8 décembre 2019, par Yagiz

  Version information

  • fluent-ffmpeg version : 2.1.2
  • ffmpeg version : ffmpeg version 4.1.3
  • OS : mac os x mojave 10.14.3

  Code to reproduce

  First cut the videos using this command :

  const cutVideo = async (currentWord) => {
  
      return new Promise((resolve, reject) => {
  
          console.log('cutting video', currentWord.file)
  
          ffmpeg(currentWord.file)
  
              .videoCodec('libx264')
  
              // .addOptions('-vf "setdar=ratio=16/9:max=1000"')
  
              .on('start', command => console.log('command', command))
  
              .on('error', reject)
  
              .on('end', resolve)
  
              .withSize('640x360')
  
              .withAspect('16:9')
  
              .applyAutopadding(true, 'black')
  
              .saveToFile(currentWord.file.replace('-unfinished', ''), './')
  
      })
  
  }

  Later merge them together using .mergeToFile() command :

  const mergeFilesAsync = async function(files, folder, filename)
  
  {
  
      return new Promise((resolve, reject) => {
  
          console.log('merging files', files)
  
          var cmd = ffmpeg({ logger: console })
  
              .videoCodec('libx264')
  
              .on('start', command => console.log('command', command))
  
              .on('error', reject)
  
              .on('end', resolve)
  
  
  
          for (var i = 0; i < files.length; i++)
  
          {
  
              const currentWord = files[i]
  
              cmd.input(currentWord.file.replace('-unfinished', ''))
  
          }
  
  
  
          cmd.mergeToFile(folder + "/" + filename, folder);
  
      });
  
  }

  Expected results

  The videos resized in cutVideo function should have 640x360 size with 16:9 aspect ratio.

  Observed results

  The first video processed had a dimension of : 850 × 480, the output after processing it is : 642 × 360 (It should be 640x360)

  The second video processed had a dimension of : 1152 × 480, the output after processing it is : 638 × 360

  The third video processed had a dimension of 853 × 480, the output after processing it is : 642 × 360

  FFmpeg command produced by fluent-ffmpeg :

  ffmpeg -i /Users/yagiz/Desktop/video-creator/what's-unfinished.mp4 -y -vcodec libx264 -filter:v scale=w='if(gt(a,1.7777777777777777),640,trunc(360*a/2)*2)':h='if(lt(a,1.7777777777777777),360,trunc(640/a/2)*2)',pad=w=640:h=360:x='if(gt(a,1.7777777777777777),0,(640-iw)/2)':y='if(lt(a,1.7777777777777777),0,(360-ih)/2)':color=black /Users/yagiz/Desktop/video-creator/what's.mp4
  
  cutting video /Users/yagiz/Desktop/video-creator/up?-unfinished.mp4

  and

  ffmpeg -i /Users/yagiz/Desktop/video-creator/up?-unfinished.mp4 -y -vcodec libx264 -filter:v scale=w='if(gt(a,1.7777777777777777),640,trunc(360*a/2)*2)':h='if(lt(a,1.7777777777777777),360,trunc(640/a/2)*2)',pad=w=640:h=360:x='if(gt(a,1.7777777777777777),0,(640-iw)/2)':y='if(lt(a,1.7777777777777777),0,(360-ih)/2)':color=black /Users/yagiz/Desktop/video-creator/up?.mp4

  I think that 1.77777 value in this command produces a lower bound or an upper bound of the actual item.

  Any idea where the issue lies ?

  Thanks !

• problems playing h264 generated by ffmpeg rawvideo with vlc

  1er octobre 2019, par Alex

  I am using an application that generates frames in rgba format, I added some code to launch ffmpeg (popen) and pass the frames generated as input, I use ffmpeg with the following arguments :

  ffmpeg-cuda -y -f rawvideo -s 1920x1080 -pix_fmt rgba -r 25 -fflags +genpts -i - -an -r 25 -pix_fmt yuv420p -c:v h264_nvenc \
  
          -rc:v vbr_hq -cq:v 19 -b:v 2500k -maxrate:v 5000k -profile:v high /tmp/output.264

  the file is created and is displayed correctly, vlc manages to reproduce it but shows duration 0, if I jump to a point in the file it does it but has some problems :

  [00007f0e8cc02080] main decoder error: Could not convert timestamp 1624400802 for FFmpeg
  
  [00007f0e8cc02080] main decoder error: Timestamp conversion failed (delay 300000, buffering 100000, bound 9000000)

  I think it’s a pts problem but I’m not sure, at the moment I don’t know how to fix it, I’m looking at the ffmpeg arguments, suggestions ?

• can't read mp4 in opencv3.2 (ubuntu, python3)

  28 mars 2017, par lhk

  I’ve ran into a problem with my opencv installation, it is unable to open an mp4 video. My system is ubuntu 16.04, 64bit, opencv3.2 used from python 3.5.

  VideoCapture.read returns False and None.

  There are other questions with this problem, but they target different platforms or different opencv versions.

  Apparently, I’m missing the proper codec.
  So I ran make uninstall from my build directory, purged opencv* with apt and built from source again. This time making sure that ffmpeg was installed before the compilation.

  Here are my steps :

  • clone opencv and opencv_contrib
  • cd opencv/
  • mkdir build
  • cd build
  • cmake -D CMAKE_BUILD_TYPE=RELEASE     -D CMAKE_INSTALL_PREFIX=/usr/local     -D INSTALL_PYTHON_EXAMPLES=ON     -D INSTALL_C_EXAMPLES=OFF     -D OPENCV_EXTRA_MODULES_PATH=../../opencv_contrib/modules     -D BUILD_EXAMPLES=ON ..
  • make -j 8
  • sudo make install

  I checked the output of cmake, ffmpeg is there :

  Video I/O:
  
  --     DC1394 1.x:                  NO
  
  --     DC1394 2.x:                  NO
  
  --     FFMPEG:                      YES
  
  --       avcodec:                   YES (ver 56.60.100)
  
  --       avformat:                  YES (ver 56.40.101)
  
  --       avutil:                    YES (ver 54.31.100)
  
  --       swscale:                   YES (ver 3.1.101)
  
  --       avresample:                NO
  
  --     GStreamer:                   NO
  
  --     OpenNI:                      NO
  
  --     OpenNI PrimeSensor Modules:  NO
  
  --     OpenNI2:                     NO
  
  --     PvAPI:                       NO
  
  --     GigEVisionSDK:               NO
  
  --     Aravis SDK:                  NO
  
  --     UniCap:                      NO
  
  --     UniCap ucil:                 NO
  
  --     V4L/V4L2:                    NO/YES
  
  --     XIMEA:                       NO
  
  --     Xine:                        NO
  
  --     gPhoto2:                     NO

  But the problem persists. How can I fix this ?

  UPDATE

  I had to manually remove some .so files from /usr/local.

  Then I installed all avi related codecs I could find.
  https://wiki.ubuntuusers.de/Codecs/
  plus libavcodec-extra and ffmpeg

  Then I recompiled and now it works.