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• Merge commit ’fa8934d6d6a0bb290010bdf16265c40b331d56fb’

  10 décembre 2014, par Michael Niedermayer

  Merge commit ’fa8934d6d6a0bb290010bdf16265c40b331d56fb’
  * commit ’fa8934d6d6a0bb290010bdf16265c40b331d56fb’ :
  
    dashenc : log file output progress in verbose mode
  Merged-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavformat/dashenc.c

• Android opengl es YUV to RGB conversion using shaders

  1er février 2014, par DSG

  I am working on a video player for android device, in which I am using ffmpeg for decoding and opengl es for rendering. I am stuck at one point where I am using opengl es shaders for YUV to RGB conversion. Application is able to display image but its not displaying correct colors. After conervting from YUV to RGB, image only displays green and pink colors. I did searched on google, but no solution found. Can any one please help me on this topic ?

  I am getting three different buffers (y, u, v) from ffmpeg and then I am passing these buffers to 3 textures as it is.

  Here are shaders I am using.

  static const char kVertexShader[] =
  
  "attribute vec4 vPosition;      \n"
  
    "attribute vec2 vTexCoord;        \n"
  
    "varying vec2 v_vTexCoord;        \n"
  
  "void main() {                        \n"
  
      "gl_Position = vPosition;       \n"
  
      "v_vTexCoord = vTexCoord;       \n"
  
  "}                                          \n";
  
  
  
  static const char kFragmentShader[] =
  
      "precision mediump float;               \n"
  
      "varying vec2 v_vTexCoord;          \n"
  
      "uniform sampler2D yTexture;        \n"
  
      "uniform sampler2D uTexture;        \n"
  
      "uniform sampler2D vTexture;        \n"
  
      "void main() {                      \n"
  
          "float y=texture2D(yTexture, v_vTexCoord).r;\n"
  
          "float u=texture2D(uTexture, v_vTexCoord).r - 0.5;\n"
  
          "float v=texture2D(vTexture, v_vTexCoord).r - 0.5;\n"
  
          "float r=y + 1.13983 * v;\n"
  
          "float g=y - 0.39465 * u - 0.58060 * v;\n"
  
          "float b=y + 2.03211 * u;\n"
  
          "gl_FragColor = vec4(r, g, b, 1.0);\n"
  
      "}\n";
  
  
  
      static const GLfloat kVertexInformation[] =
  
      {
  
           -1.0f, 1.0f,           // TexCoord 0 top left
  
           -1.0f,-1.0f,           // TexCoord 1 bottom left
  
            1.0f,-1.0f,           // TexCoord 2 bottom right
  
            1.0f, 1.0f            // TexCoord 3 top right
  
      };
  
      static const GLshort kTextureCoordinateInformation[] =
  
      {
  
           0, 0,         // TexCoord 0 top left
  
           0, 1,         // TexCoord 1 bottom left
  
           1, 1,         // TexCoord 2 bottom right
  
           1, 0          // TexCoord 3 top right
  
      };
  
      static const GLuint kStride = 0;//COORDS_PER_VERTEX * 4;
  
      static const GLshort kIndicesInformation[] =
  
      {
  
           0, 1, 2, 
  
           0, 2, 3
  
      };

  Here is another person who had asked same question : Camera frame yuv to rgb conversion using GL shader language

  Thank You.

  UPDATE :

  ClayMontgomery's shaders.

  const char* VERTEX_SHADER = "\
  
  attribute vec4 a_position;\
  
  attribute vec2 a_texCoord;\
  
  varying   vec2 gsvTexCoord;\
  
  varying   vec2 gsvTexCoordLuma;\
  
  varying   vec2 gsvTexCoordChroma;\
  
  \
  
  void main()\
  
  {\
  
      gl_Position = a_position;\
  
      gsvTexCoord = a_texCoord;\
  
      gsvTexCoordLuma.s = a_texCoord.s / 2.0;\
  
      gsvTexCoordLuma.t = a_texCoord.t / 2.0;\
  
      gsvTexCoordChroma.s = a_texCoord.s / 4.0;\
  
      gsvTexCoordChroma.t = a_texCoord.t / 4.0;\
  
  }";
  
  
  
  
  
  const char* YUV_FRAGMENT_SHADER = "\
  
  precision highp float;\
  
  uniform sampler2D y_texture;\
  
  uniform sampler2D u_texture;\
  
  uniform sampler2D v_texture;\
  
  varying   vec2 gsvTexCoord;\
  
  varying vec2 gsvTexCoordLuma;\
  
  varying vec2 gsvTexCoordChroma;\
  
  \
  
  void main()\
  
  {\
  
      float y = texture2D(y_texture, gsvTexCoordLuma).r;\
  
      float u = texture2D(u_texture, gsvTexCoordChroma).r;\
  
      float v = texture2D(v_texture, gsvTexCoordChroma).r;\
  
      u = u - 0.5;\
  
      v = v - 0.5;\
  
      vec3 rgb;\
  
      rgb.r = y + (1.403 * v);\
  
      rgb.g = y - (0.344 * u) - (0.714 * v);\
  
      rgb.b = y + (1.770 * u);\
  
      gl_FragColor = vec4(rgb, 1.0);\
  
  }";

  Here is output :

  

• Unknown encoder 'libx264' - Heroku Rails App

  11 février 2014, par scientiffic

  In my Rails app, I installed ffmpeg on Heroku in order to transcode uploaded video files.

  This worked fine until I added exiftool functionality (as outlined in this stackoverflow post) and I started getting the error 'Unknown encoder libx264' when I try to transcode videos (ONLY when I try uploading video through Heroku ; I don't get any errors when I upload videos locally). The full error message from my heroku logs is below :

  Running transcoding...
  
  ffmpeg -y -i /app/public/uploads/tmp/1392153416-9-9551/portrait.mp4 -vcodec libx264 -acodec libfaac -s 640x360  -vf transpose=1 -aspect 0.5625 /app/public/uploads/tmp/1392153416-9-9551/tmpfile.mp4
  
  
  
  Failed encoding...
  
  ffmpeg -y -i /app/public/uploads/tmp/1392153416-9-9551/portrait.mp4 -vcodec libx264 -acodec libfaac -s 640x360  -vf transpose=1 -aspect 0.5625 /app/public/uploads/tmp/1392153416-9-9551/tmpfile.mp4
  
  
  
  Unknown encoder 'libx264'

  I don't know why I'm getting this error because I installed ffmpeg with the —enable-libx264 option (my full installation instructions are here), and when I run 'which x264' in the heroku bash, it does return the correct path.

  The strangest part is that I'm testing everything on my test server right now, and my deployed app on my main server is able to run the transcoding with no problems using libx264. The only difference between my main server and test server is the addition of exiftool.

  Does anyone have any idea what's going in here ??