Recherche avancée

Sur d’autres sites (9509)

• Making a lossless video from a sequence of png image buffers using ffmpeg and c++

  3 juillet 2013, par Ven

  I am trying to create a movie file form a sequence of png buffers.
  Can some one help me in understating how to create loss less mpeg4 video file from png buffers using ffmpeg and c++.
  I know we can do this by command line if you are using .png files but i would like implement using c++ as i am creating loss less png buffer from raw data.

• Ffmpeg auto Scaling does not working

  2 juillet 2013, par thevoipman

  I am trying to scale any videos that has a width greater than 720 to 720 - i do not want any 1080p stuff. The commands I am using is below and where ever I add scale=720 :-1, it would give me an error saying that the option scale is not available for use.

  FFMPEG_COMMAND="ffmpeg -i "\"$FILENAME\"" -vf "\""movie=water.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:main_h-overlay_h-10[out]\""" -ac 2 -vcodec libx264 -threads 10 -acodec libfaac -async 2 "\""$OUTPUT_DIRECTORY/abc$OUTPUTFILENAME"\"

  Any kind of help I can get with this is greatly appreciated !

• a lot of GREEN Color at YUV420p —> RGB in OpenGL 2.0 Shader on iOS

  25 octobre 2012, par 이형근

  I want to make a movie player for iOS using ffmpeg and OpenGL ES 2.0
  but I have some problem. Output RGB image has a lot of GREEN color.
  This is code and images

  • 480x320 width & height :
  • 512x512 Texture width & height

  I got a YUV420p row data from ffmpeg AVFrame.

      for (int i = 0, nDataLen = 0; i < 3; i++) {
  
          int nShift = (i == 0) ? 0 : 1;
  
          uint8_t *pYUVData = (uint8_t *)_frame->data[i];
  
          for (int j = 0; j < (mHeight >> nShift); j++) {
  
              memcpy(&pData->pOutBuffer[nDataLen], pYUVData, (mWidth >> nShift));
  
              pYUVData += _frame->linesize[i];
  
              nDataLen += (mWidth >> nShift);
  
          }
  
      }

  and prepare texture for Y, U & V channel.

  //: U Texture
  
      if (sampler1Texture) glDeleteTextures(1, &sampler1Texture);
  
  
  
      glActiveTexture(GL_TEXTURE1);
  
      glGenTextures(1, &sampler1Texture);
  
      glBindTexture(GL_TEXTURE_2D, sampler1Texture);
  
  
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  
      // This is necessary for non-power-of-two textures
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  
      glEnable(GL_TEXTURE_2D);
  
  
  
      glTexImage2D(GL_TEXTURE_2D, 
  
                   0, 
  
                   GL_LUMINANCE, 
  
                   texW / 2, 
  
                   texH / 2, 
  
                   0, 
  
                   GL_LUMINANCE, 
  
                   GL_UNSIGNED_BYTE,
  
                   NULL);
  
  
  
      //: V Texture
  
      if (sampler2Texture) glDeleteTextures(1, &sampler2Texture);
  
  
  
      glActiveTexture(GL_TEXTURE2);
  
      glGenTextures(1, &sampler2Texture);
  
      glBindTexture(GL_TEXTURE_2D, sampler2Texture);
  
  
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  
      // This is necessary for non-power-of-two textures
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  
      glEnable(GL_TEXTURE_2D);
  
  
  
      glTexImage2D(GL_TEXTURE_2D, 
  
                   0, 
  
                   GL_LUMINANCE, 
  
                   texW / 2, 
  
                   texH / 2, 
  
                   0, 
  
                   GL_LUMINANCE,
  
                   GL_UNSIGNED_BYTE,
  
                   NULL);
  
  
  
      //: Y Texture
  
      if (sampler0Texture) glDeleteTextures(1, &sampler0Texture);
  
  
  
      glActiveTexture(GL_TEXTURE0);
  
      glGenTextures(1, &sampler0Texture);
  
      glBindTexture(GL_TEXTURE_2D, sampler0Texture);
  
  
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  
      // This is necessary for non-power-of-two textures
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  
      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  
      glEnable(GL_TEXTURE_2D);
  
  
  
      glTexImage2D(GL_TEXTURE_2D, 
  
                   0, 
  
                   GL_LUMINANCE, 
  
                   texW, 
  
                   texH, 
  
                   0, 
  
                   GL_LUMINANCE,
  
                   GL_UNSIGNED_BYTE, 
  
                   NULL);

  Rendering part is below.

  int _idxU = mFrameW * mFrameH;
  
  int _idxV = _idxU + (_idxU / 4);
  
  
  
  // U data
  
  glActiveTexture(GL_TEXTURE1);
  
  glBindTexture(GL_TEXTURE_2D, sampler1Texture);
  
  glUniform1i(sampler1Uniform, 1);
  
  
  
  glTexSubImage2D(
  
                  GL_TEXTURE_2D, 
  
                  0, 
  
                  0, 
  
                  0, 
  
                  mFrameW / 2,            // source width
  
                  mFrameH / 2,            // source height
  
                  GL_LUMINANCE,
  
                  GL_UNSIGNED_BYTE, 
  
                  &_frameData[_idxU]);
  
  
  
  // V data
  
  glActiveTexture(GL_TEXTURE2);
  
  glBindTexture(GL_TEXTURE_2D, sampler2Texture);
  
  glUniform1i(sampler2Texture, 2);
  
  
  
  glTexSubImage2D(
  
                  GL_TEXTURE_2D, 
  
                  0, 
  
                  0, 
  
                  0, 
  
                  mFrameW / 2,            // source width
  
                  mFrameH / 2,            // source height
  
                  GL_LUMINANCE,
  
                  GL_UNSIGNED_BYTE,
  
                  &_frameData[_idxV]);
  
  
  
  // Y data
  
  glActiveTexture(GL_TEXTURE0);
  
  glBindTexture(GL_TEXTURE_2D, sampler0Texture);
  
  glUniform1i(sampler0Uniform, 0);
  
  
  
  glTexSubImage2D(
  
                  GL_TEXTURE_2D, 
  
                  0, 
  
                  0, 
  
                  0, 
  
                  mFrameW,            // source width
  
                  mFrameH,            // source height
  
                  GL_LUMINANCE,
  
                  GL_UNSIGNED_BYTE,
  
                  _frameData);

  Vertex Shader & Fragment Shader is below.

  attribute vec4 Position;
  
  attribute vec2 TexCoordIn;
  
  
  
  varying vec2 TexCoordOut;
  
  varying vec2 TexCoordOut_UV;
  
  
  
  uniform mat4 Projection;
  
  uniform mat4 Modelview;
  
  
  
  void main()
  
  {
  
      gl_Position = Projection * Modelview * Position;
  
      TexCoordOut = TexCoordIn;
  
  }
  
  
  
  
  
  
  
  uniform sampler2D sampler0; // Y Texture Sampler
  
  uniform sampler2D sampler1; // U Texture Sampler
  
  uniform sampler2D sampler2; // V Texture Sampler
  
  
  
  varying highp vec2 TexCoordOut;
  
  
  
  void main()
  
  {
  
      highp float y = texture2D(sampler0, TexCoordOut).r;
  
      highp float u = texture2D(sampler2, TexCoordOut).r - 0.5;
  
      highp float v = texture2D(sampler1, TexCoordOut).r - 0.5;
  
  
  
      //y = 0.0;
  
      //u = 0.0;
  
      //v = 0.0;
  
  
  
      highp float r = y + 1.13983 * v;
  
      highp float g = y - 0.39465 * u - 0.58060 * v;
  
      highp float b = y + 2.03211 * u;
  
  
  
      gl_FragColor = vec4(r, g, b, 1.0);
  
  }

  Y Texture (Grayscale) is correct but U & V has a lot of Green Color.
  So final RGB image (Y+U+V) has a lot of GREEN Color.
  What's the problem ?

  Please help.
  thanks.