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• Using 'blend' filter with ffmpeg colors my video pink

  12 octobre 2022, par Ilan Yashuk

  I am using ffmpeg's library fluent-ffmpeg in nodejs.

  


  My purpose is to blend a black box with text upon a video (using 'lighten' blend filter)
so the background will be deleted in a clean & beautiful way.

  


  For some reason the video turns pink after I do that.

  


  The code for blending :

  


  return new Promise((resolve, reject) => {
ffmpeg()
  .input(videoPath) // input '0', the background video
  .input(picturePath) // input '1', the black box with text
  .complexFilter([
    {
      filter: "blend",
      inputs: ["1", "0"],
      options: {
        all_mode: "lighten",
      },
    },
  ])

  .saveToFile(endPath)
  .on("error", (err) => {
    console.log(err);
    reject(false);
  })
  .on("end", () => {
    resolve(true);
  });


  


  Before the blend :

  


  

  


  After the blend :


  


  I've read here that the problem's cause may be that blend's format is YUV and not GBRP. I've tried it and it didn't work.

  


  Any help would be appreciated. If possible, please give a code answer and not a command-line answer because converting it sometimes tends to do problems.

  


• opengl es yuv to rgb conversion display only green and pink colors

  3 février 2014, par DSG

  I am doing yuv to rgb conversion using opengl shaders. But its only show green and pink colors. I am using ffmpeg to decode movie. I am beginner in this, so have no idea how to solve it. ffmpeg give me three buffers of yuv. I am directly assigning these buffers to three textures.

  Here are shaders I am using.

  static const char* VERTEX_SHADER =
  
  "attribute vec4 vPosition;                      \n"
  
  "attribute vec2 a_texCoord;                     \n"
  
  "varying vec2 tc;                               \n"
  
  "uniform mat4 u_mvpMat;                         \n"
  
  "void main()                                    \n"
  
  "{                                              \n"
  
  "   gl_Position = u_mvpMat * vPosition;         \n"
  
  "   tc = a_texCoord;                            \n"
  
  "}                                              \n";
  
  
  
  static const char* YUV_FRAG_SHADER =
  
  "#ifdef GL_ES                                   \n"
  
  "precision highp float;                         \n"
  
  "#endif                                         \n"
  
  "varying vec2 tc;                               \n"
  
  "uniform sampler2D TextureY;                    \n"
  
  "uniform sampler2D TextureU;                    \n"
  
  "uniform sampler2D TextureV;                    \n"
  
  "uniform float imageWidth;                      \n"
  
  "uniform float imageHeight;                     \n"
  
  
  
  "void main(void)                                \n"
  
  "{                                              \n"
  
      "float nx, ny;                              \n"
  
      "vec3 yuv;                                  \n"
  
      "vec3 rgb;                                  \n"
  
      "nx = tc.x;                                 \n"
  
      "ny = tc.y;                                 \n"
  
  
  
      "yuv.x = texture2D(TextureY, tc).r;         \n"
  
      "yuv.y = texture2D(TextureU, vec2(nx/2.0, ny/2.0)).r - 0.5;   \n"
  
      "yuv.z = texture2D(TextureV, vec2(nx/2.0, ny/2.0)).r - 0.5;   \n"
  
  
  
      // Using BT.709 which is the standard for HDTV
  
      "rgb = mat3( 1,              1,      1,     \n"
  
                  "0,       -0.18732, 1.8556,     \n"
  
                  "1.57481, -0.46813,      0)*yuv;\n"
  
  
  
      // BT.601, which is the standard for SDTV is provided as a reference
  
      //"rgb = mat3( 1,            1,     1,        \n"
  
      //            "0,     -0.34413, 1.772,        \n"
  
      //            "1.402, -0.71414,     0) * yuv; \n"
  
      "gl_FragColor = vec4(rgb, 1.0);             \n"
  
  "}                                              \n";

  Output :

  

  What wrong am I doing ? Please help me out with this.

  Thank You.

  UPDATE :

  While debugging ffmpeg decoding, I found that ffmpeg decoder give PIX_FMT_YUV420P output format. Do I have to make some tweaks to get correct image colors ?

• FFmpeg screen blend mode turns image pink

  18 mai 2021, par IAmDamoSuzuki

  I'm having trouble using the screen blend mode. I'm trying to create a video delay/echo effects. I have things working fairly well, but whenever I try to use the screen blend mode I get a pink image. Other blend modes don't have this issue, but the screen mode is likely going to give me the best visual results.

  


  I see that someone else asked a similar question here, and the answers suggested converting to RGBa before doing the blends. I've tried this and it didn't work. Here's my code and ffmpeg info.

  


  ffmpeg -i sampleVideo.mov -c:v prores -profile:v 3 -filter_complex "split[dry][toEcho];[toEcho]setpts=PTS+0.2/TB[wet];[wet][dry]blend=all_mode=screen:all_opacity=1,format=yuv422p10le[out]" -map [out] sampleVideo_echo.mov


  


  ffmpeg info :

  


  ffmpeg version 4.2.3 Copyright (c) 2000-2020 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.3_1 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags=-fno-stack-check --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/morgan/Movies/AVAA/TapeDamage01.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.20.100
  Duration: 00:00:05.16, start: 0.000000, bitrate: 3717 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x480 [SAR 81:80 DAR 27:20], 3560 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : Apple Video Media Handler
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 160 kb/s (default)
    Metadata:
      handler_name    : Apple Sound Media Handler
File '/Users/morgan/Movies/AVAA/TapeDamage01_echo.mov' already exists. Overwrite ? [y/N] y
Stream mapping:
  Stream #0:0 (h264) -> split
  format -> Stream #0:0 (prores)
Press [q] to stop, [?] for help
Output #0, mov, to '/Users/morgan/Movies/AVAA/TapeDamage01_echo.mov':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.29.100
    Stream #0:0: Video: prores (HQ) (apch / 0x68637061), yuv422p10le, 640x480 [SAR 81:80 DAR 27:20], q=2-31, 200 kb/s, 29.97 fps, 30k tbn, 29.97 tbc (default)
    Metadata:
      encoder         : Lavc58.54.100 prores


  


  Here's a sample of the input file :

  


  

  


  and here's the pink output