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• Android combine videos and images into one video

  15 septembre 2017, par Patrix Williams

  I need to make an app which does the following :

  • User can select images and videos from his gallery
  • This selection must be made into one video with square dimensions
  • A watermark has to be added to the resulting video
  • All audio must be removed from all videos, and my own audio has to be added (mp3 file)

  What would be the option to do this ? I see alot of answers which uses ffmpeg but on Android API > 22 this has huge performance issues with has text relocations.

  What would be the best solution ?

• advanced ffmpeg compression controll

  27 décembre 2015, par Daniel Mahler

  I am using very aggressive video compression, eg -crf 51. I am using this for ’artistic’ effect, so what I am doing may not make sense from a normal video compression point of view.

  So far I have only been using very basic compression control using only the -crf or -b:v flags. The results look like ffmpeg divides images into square patches and the makes smooth approximations within the patches. This gives 2 control dimensions to the process : the patch size and the aggressiveness of the smoothing within the patches.

  It have found that ffmpeg uses both parameters to some extent, but there appears to be an absolute maximum patch size in pixels beyond which it will not go regardless of the frame size.
  After that it will only increase compression by reducing the detail within the patches.

  This is suboptimal for high resolution video, where this becomes equivalent to reducing the resolution. The problem is particularly noticeable on fractal like images which have large featureless region as well as regions of high detail.

  How can I tell ffmpeg to increase the maximum patch size and retain more detail within the patches ?

• ffmpeg resize maintain aspect - filter not found

  4 décembre 2015, par paul

  I am trying to create image thumbnails that maintain the aspect of the orginal but crop it if the dimensions are too far out.
  found a likely code snippet here

  ffmpeg -i Einstein_500_459.jpg -vf scale="'if(gt(a,320/240),320,-1)':'if(gt(a,320/240),-1,240)'" Einstein_320x240_fit.png

  but cannot get ffmpeg to execute it. as is it generates error in terminal :

  ffmpeg -i Einstein_500_459.jpg -vf scale="'if(gt(a,320/240),320,-1)':'if(gt(a,320/240),-1,240)'" Einstein_320x240_fit.png
  
  ffmpeg version 0.10.12-7:0.10.12-1~precise1 Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Apr 26 2014 09:49:36 with gcc 4.6.3
  
    configuration: --arch=amd64 --disable-stripping --enable-pthreads --enable-runtime-cpudetect --extra-version='7:0.10.12-1~precise1' --libdir=/usr/lib/x86_64-linux-gnu --prefix=/usr --enable-bzlib --enable-libdc1394 --enable-libfreetype --enable-frei0r --enable-gnutls --enable-libgsm --enable-libmp3lame --enable-librtmp --enable-libopencv --enable-libopenjpeg --enable-libpulse --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-vaapi --enable-vdpau --enable-libvorbis --enable-libvpx --enable-zlib --enable-gpl --enable-postproc --enable-libcdio --enable-x11grab --enable-libx264 --shlibdir=/usr/lib/x86_64-linux-gnu --enable-shared --disable-static
  
    libavutil      51. 35.100 / 51. 35.100
  
    libavcodec     53. 61.100 / 53. 61.100
  
    libavformat    53. 32.100 / 53. 32.100
  
    libavdevice    53.  4.100 / 53.  4.100
  
    libavfilter     2. 61.100 /  2. 61.100
  
    libswscale      2.  1.100 /  2.  1.100
  
    libswresample   0.  6.100 /  0.  6.100
  
    libpostproc    52.  0.100 / 52.  0.100
  
  Input #0, image2, from 'Einstein_500_459.jpg':
  
    Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: mjpeg, yuvj444p, 500x459 [SAR 300:300 DAR 500:459], 25 tbr, 25 tbn, 25 tbc
  
  Incompatible pixel format 'yuvj444p' for codec 'png', auto-selecting format 'rgb24'
  
  [buffer @ 0x236d720] w:500 h:459 pixfmt:yuvj444p tb:1/1000000 sar:300/300 sws_param:
  
  [scale @ 0x235d5e0] [Eval @ 0x7fffcb68f270] Missing ')' or too many args in 'if(gt(a,320/240),320,-1)'
  
  [scale @ 0x235d5e0] [Eval @ 0x7fffcb68f270] Missing ')' or too many args in 'if(gt(a,320/240),-1,240)'
  
  Error when evaluating the expression 'if(gt(a,320/240),-1,240)'.
  
  Maybe the expression for out_w:'if(gt(a,320/240),320,-1)' or for out_h:'if(gt(a,320/240),-1,240)' is self-referencing.
  
  Error opening filters!

  after escaping single quotes

  ffmpeg -i Einstein_500_459.jpg -vf scale="\'if(gt(a,320/240),320,-1)\':\'if(gt(a,320/240),-1,240)\'" Einstein_320x240_fit.png

  it generates error

  ffmpeg -i Einstein_500_459.jpg -vf scale="\'if(gt(a,320/240),320,-1)\':\'if(gt(a,320/240),-1,240)\'" Einstein_320x240_fit.png
  
  ffmpeg version 0.10.12-7:0.10.12-1~precise1 Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Apr 26 2014 09:49:36 with gcc 4.6.3
  
    configuration: --arch=amd64 --disable-stripping --enable-pthreads --enable-runtime-cpudetect --extra-version='7:0.10.12-1~precise1' --libdir=/usr/lib/x86_64-linux-gnu --prefix=/usr --enable-bzlib --enable-libdc1394 --enable-libfreetype --enable-frei0r --enable-gnutls --enable-libgsm --enable-libmp3lame --enable-librtmp --enable-libopencv --enable-libopenjpeg --enable-libpulse --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-vaapi --enable-vdpau --enable-libvorbis --enable-libvpx --enable-zlib --enable-gpl --enable-postproc --enable-libcdio --enable-x11grab --enable-libx264 --shlibdir=/usr/lib/x86_64-linux-gnu --enable-shared --disable-static
  
    libavutil      51. 35.100 / 51. 35.100
  
    libavcodec     53. 61.100 / 53. 61.100
  
    libavformat    53. 32.100 / 53. 32.100
  
    libavdevice    53.  4.100 / 53.  4.100
  
    libavfilter     2. 61.100 /  2. 61.100
  
    libswscale      2.  1.100 /  2.  1.100
  
    libswresample   0.  6.100 /  0.  6.100
  
    libpostproc    52.  0.100 / 52.  0.100
  
  Input #0, image2, from 'Einstein_500_459.jpg':
  
    Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
  
      Stream #0:0: Video: mjpeg, yuvj444p, 500x459 [SAR 300:300 DAR 500:459], 25 tbr, 25 tbn, 25 tbc
  
  Incompatible pixel format 'yuvj444p' for codec 'png', auto-selecting format 'rgb24'
  
  [buffer @ 0x1897720] w:500 h:459 pixfmt:yuvj444p tb:1/1000000 sar:300/300 sws_param:
  
  No such filter: '320/240)'
  
  Error opening filters!

  is this just a syntax problem ? or is my ffmpeg missing something ? or what ?
  this is ubuntu 12.04 with what i believe is a full install of ffmpeg, not the libav default thing. any help is appreciated.