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• configure : select riffdec for act demuxer

  1er novembre 2019, par Lou Logan

  configure : select riffdec for act demuxer
  Signed-off-by : Lou Logan <lou@lrcd.com>
  
  Signed-off-by : Carl Eugen Hoyos <ceffmpeg@gmail.com>
  

  • [DH] configure

• Changing Audio Volume using FFmpeg Android Error

  23 août 2018, par kataroty

  I am using FFmpeg and I need to change the volume of the Audio.

  This is the command that should change the volume of the audio :

  ffmpeg -i input.wav -filter:a "volume=1.5" output.wav

  I read from somewhere that it had to overwrite the file if it already existed so either one had to delete the file or use -y. When I tried to do it without the -y command it never got to onSuccess() or ´onFailure(), but it always printed out the onStart() message.

  String[] cmdy = { "-i -y" , pcmtowavTempFile.toString(),  "-af", "volume=5", pcmtowavTempFile.toString()};
  
      ffmpeg.execute(cmdy, new ExecuteBinaryResponseHandler() {
  
  
  
          @Override
  
          public void onStart() {
  
              System.out.println("ayy: onStart");
  
          }
  
  
  
          @Override
  
          public void onSuccess(String message) {
  
              System.out.println("ayy: onSuccess");
  
              super.onSuccess(message);
  
          }
  
          @Override
  
          public void onFailure(String message) {
  
              System.out.println("ayy: onFailure " + message);
  
              super.onFailure(message);
  
          }
  
  });

  At the moment I get this error :

  ffmpeg version n4.0-39-gda39990 Copyright (c) 2000-2018 the FFmpeg developers
  
    built with gcc 4.9.x (GCC) 20150123 (prerelease)
  
    configuration: --target-os=linux --cross-prefix=/root/bravobit/ffmpeg-android/toolchain-android/bin/arm-linux-androideabi- --arch=arm --cpu=cortex-a8 --enable-runtime-cpudetect --sysroot=/root/bravobit/ffmpeg-android/toolchain-android/sysroot --enable-pic --enable-libx264 --enable-ffprobe --enable-libopus --enable-libvorbis --enable-libfdk-aac --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-fontconfig --enable-libvpx --enable-libass --enable-yasm --enable-pthreads --disable-debug --enable-version3 --enable-hardcoded-tables --disable-ffplay --disable-linux-perf --disable-doc --disable-shared --enable-static --enable-runtime-cpudetect --enable-nonfree --enable-network --enable-avresample --enable-avformat --enable-avcodec --enable-indev=lavfi --enable-hwaccels --enable-ffmpeg --enable-zlib --enable-gpl --enable-small --enable-nonfree --pkg-config=pkg-config --pkg-config-flags=--static --prefix=/root/bravobit/ffmpeg-android/build/armeabi-v7a --extra-cflags='-I/root/bravobit/ffmpeg-android/toolchain-android/include -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-strict-overflow -fstack-protector-all' --extra-ldflags='-L/root/bravobit/ffmpeg-android/toolchain-android/lib -Wl,-z,relro -Wl,-z,now -pie' --extra-cxxflags=
  
    libavutil      56. 14.100 / 56. 14.100
  
    libavcodec     58. 18.100 / 58. 18.100
  
    libavformat    58. 12.100 / 58. 12.100
  
    libavdevice    58.  3.100 / 58.  3.100
  
    libavfilter     7. 16.100 /  7. 16.100
  
    libavresample   4.  0.  0 /  4.  0.  0
  
    libswscale      5.  1.100 /  5.  1.100
  
    libswresample   3.  1.100 /  3.  1.100
  
    libpostproc    55.  1.100 / 55.  1.100
  
  Unrecognized option 'i -y'.

  Which clearly states that it does not recognize option i -y, but also as I said earlier then if I remove the -y it never gets to onSuccess() or onFailure().

  help me to find a solution. Thanks.

• Overlaying one video on another one, and making black pixels transparent

  25 janvier 2023, par Michael A

  I'm trying to use FFMPEG to create a video with one video overlayed on top another.

  



  I have 2 MP4s. I need to make all BLACK pixels in the overlay video transparent so that I can see the main video underneath it.

  



  I found two ways to overlay one video on another :

  



  First, the following positions the overlay in the center, and therefore, hides that portion of the main video beneath it :

  



      ffmpeg -i 1.mp4 -vf "movie=2.mp4 [a]; [in][a] overlay=352:0 [b]" combined.mp4 -y


  



  And, this one, places the overlay video on the left, but it's opacity is set to 50% so at least other one beneath it is visible :

  



  ffmpeg -i 1.mp4 -i 2.mp4 -filter_complex "[0:v]setpts=PTS-STARTPTS[top]; [1:v]setpts=PTS-STARTPTS, format=yuva420p,colorchannelmixer=aa=0.5[bottom]; [top][bottom]overlay=shortest=0" -acodec libvo_aacenc -vcodec libx264 out.mp4 -y


  



  My goal is simply to make all black pixels in the overlay (2.mp4) completely transparent. How can this be done.