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• How convert High bitrate mp3 to lower rate using ffmpeg in android

  23 mars 2018, par Android Team

  We want to convert 320kbps mp3 file to 128kbps mp3 so currently we are using below ffmpeg command but its not working.

  ffmpeg -i input.mp3 -codec:a libmp3lame -qscale:a 5 output.mp3

  Result :-the output bitrate same as input mp3.

  And we are following the FFmpeg Encoding guideline for that here is the link :- https://trac.ffmpeg.org/wiki/Encode/MP3

  so please suggest any solution.

• FFmpeg, low quality merge using overlay filter [closed]

  24 mars, par He2A

  I am currently building a script, part of its functionality is to generate a cover art. I want to limit the scripts dependency to ffmpeg only so please don't suggest to use any other software to do the same.

  


  For this, I am using ffmpeg to generate separate components for the coverart, code is given below :

  


  # Draws transparent circle in correct background
ffmpeg -y -f lavfi -i "color=c=0x20292FFF:s=4000x4000,format=rgba" -filter_complex "geq=r='32':g='41':b='47':a='255*(1-between(hypot(X-2000,Y-2000),0,1150))'" -frames:v 1 -update 1 background.png

# Draws a circle gradient
ffmpeg -y -f lavfi -i "gradients=s=4000x4000:c0=0x33517e:c1=0x645098:c2=0xa53f97:c3=0xdf1177:c4=0xff033e:c5=0x2f4858:n=5:y0=750:x0=750:y1=3250:x1=3250:t=linear,format=rgba" -filter_complex "geq=g='g(X,Y)':a='255*between(hypot(X-2000,Y-2000),0,1200)'" -frames:v 1 -update 1 gradcir.png

# Draws the inner symbol
ffmpeg -y -f lavfi -i "color=c=0x20292FFF:s=4000x4000,format=rgba" -vf "geq=a='255*max(lte((X-2000+(530/3)+25)+sqrt(3)*abs(Y-2000),530)*gte(X-2000+(530/3)+25,0),between(hypot(X-2000,Y-2000),570,630))':r='255*max(lte((X-2000+(530/3)+25)+sqrt(3)*abs(Y-2000),530)*gte(X-2000+(530/3)+25,0),between(hypot(X-2000,Y-2000),570,630))':g='255*max(lte((X-2000+(530/3)+25)+sqrt(3)*abs(Y-2000),530)*gte(X-2000+(530/3)+25,0),between(hypot(X-2000,Y-2000),570,630))':b='255*max(lte((X-2000+(530/3)+25)+sqrt(3)*abs(Y-2000),530)*gte(X-2000+(530/3)+25,0),between(hypot(X-2000,Y-2000),570,630))'" -frames:v 1 shape.png


  


  Now to merge all three pngs, I am using the following command :

  


  ffmpeg -y -i background.png -i gradcir.png -i shape.png -filter_complex "[0][1]overlay[tmp];[tmp][2]overlay" cover.png


  


  All the code works but the problem is that the output is severely low quality with banding and improper merges in the borders of each image.

  


  I believe png is lossless so there shouldn't be any issue with artifacts but still I experimented with different levels of png compression but to no avail. I even tried enforcing rgba format for all three images prior to merging but to no avail.

  


  For now I alleviated the problem by generating all images in 4000x4000 resolution, applying a deband filter and then resizing it to 1000x1000.

  


  ffmpeg -y -i background.png -i gradcir.png -i shape.png -filter_complex "[0][1]overlay[tmp1];[tmp1][2]overlay[tmp2];[tmp2]format=rgb24,scale=2000:2000:flags=spline,deband,scale=1000:1000:flags=lanczos" -frames:v 1 -update 1 cover.png


  


  But the above method is expensive, which is problematic for low performance systems. Can anyone find out what seems to be the issue or suggest some better way to merge it ?

  


• avfilter/vf_delogo : unbreak fate

  2 septembre 2019, par Paul B Mahol

  avfilter/vf_delogo : unbreak fate
  It is not clear what was real intention of previous commit to this filter.
  
  It was not working correctly, hopefully this is fixed now.
  
  It never checked that new x/y/w/h are actually valid, hopeffully this is fixed now.
  
  It uses named variables in expressions that are never set, still not fixed.
  
  It does not set named variables that uses actual frame widht/height, making actual
  
  expressions less usable for our users, still now fixed.
  

  • [DH] libavfilter/vf_delogo.c