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• ffmpeg alpha export color

  11 mars 2015, par TheCutestPuppy

  I’m converting a mov to h264 mp4. I have this working fine with the following command :

  ffmpeg -i v1.mov -pix_fmt yuv420p -c:v libx264 -s 1200:900  out.mp4

  While I want to remove the alpha channel, ffmpeg automatically exports it to black. I’d like to export it to a different color such as white. I can’t seem to find a way to do so. Anybody have any ideas ?

• ffmpeg convert white color to alpha

  11 janvier 2021, par tony

  Hello i took a picture with my camera :a drawing of a square frame on a white paper ; i'm trying to convert the white to transparent and keep the black color frame.

  


  So i started making 1 palette with only 2 colors to make the colors uniform and 1 palette to add the transparency

  


  ffmpeg -f lavfi -i "color=color=white:100x100" -f lavfi -i "color=color=black:100x100" -filter_complex "[0][1]hstack" -frames:v 1 blackwhite.png`
ffmpeg -i blackwhite.png -filter_complex "[0]split[a][b];[a]palettegen[pal1];[b]palettegen=reserve_transparent=on:transparency_color=white[pal2]" -map [pal1] palette1.png -map [pal2] palette2.png


  


  then i mapped the image png of the frame to convert the white to transparent and overlayed the result to a red background

  


  ffmpeg -i image.png -i palette1.png -i palette2.png -i background.png -filter_complex "[0:v][1:v]paletteuse=dither=bayer[a],[a]split[a1][a2];[a1][2:v]paletteuse=alpha_threshold=128[c];[3:v][c]overlay[d]" -map [a2] -c:v png out.png -map [d] -c:v png out1.png


  


  the png mapped to the first palette (as a test) comes as it should be, pure black and white,the second comes with no transparency at all and covers the background
what am i doing wrong ?

  


• FFMPEG output the wrong color when using it with BackColour / OutlineColour

  5 mai 2023, par Youssef

  I have tried both OutlineColour, BackColour and BoxColour none of this worked well with colors, only black/white in both opaque and with transparency works. I am not sure how to fix this code, It's been 3 days searching for a solution

  


  my color is E63946 clearly it's red

  


  

  


  When making the necessary adjustments with the code below

  


    const bgColorHex = '#E63946';
  const bgColorFFmpeg = bgColorHex.replace('#', '&H00');
  console.log(bgColorFFmpeg);


  


  I use with the code below

  


   const ffmpeg = spawn("ffmpeg", [
    "-i",
    "test.mp4",
    "-vf",
    `subtitles=${subtitlePath}:force_style='BorderStyle=3,Shadow=no,BackColour=${bgColorFFmpeg},OutlineColour=${bgColorFFmpeg}'`,
    "-c:a",
    "copy",
    "-progress", "pipe:1",
    outputPath,
  ]); 


  


  This is the result I get

  


  

  


  I tried other methods like with tinycolor, same issue

  


  const bgColor = `&H${tinycolor(bgColorHex).toHex8().substr(2)}`;


  


  Please help this is very confusing it should be easy to input a color into ffmpeg, text color on the other hand gave me no issue at all only this captions background is causing problems.

  


  Let me know if you need more info