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• Ffmpeg watermarking multiple images

  5 avril 2013, par r3zfr

  I'm a bit puzzled here and can't find an answer to the following question. Is it possible to have 2 .png files watermarked into a video in a single command line with Libavfilter ?

  I'm using this commandline, but everything I try to get the second PNG image in it fails.

  ffmpeg –i inputvideo.avi -vf "movie=watermarklogo.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:10 [out]" outputvideo.flv

• Simple example of using ffmpeg as a Python subprocess, and "checking in" on the conversion

  30 août 2012, par ensnare

  I'm looking to convert a large directory of movies from one format to another, and to check in on the status of the conversion. I'm programming in Python.

  Something like this :

  >> m = MovieGenerator()
  
  >> m.convertMovie('/path/to/movie/movie1.avi')
  
  >> print m.status
  
  >> 35 frames completed

  Is this possible (or recommended) ? Does anyone have a working example of how to use ffmpeg as a subprocess ?

  Once the conversion is happening, is there any way to "check in" on the status of the conversion (for example, how many frames have been completed ?)

• CVOpenGLESTextureCacheCreateTextureFromImage from uint8_t buffer

  6 novembre 2015, par resident_

  I’m developing an video player for iPhone. I’m using ffmpeg libraries to decode frames of video and I’m using opengl 2.0 to render the frames to the screen.

  But my render method is very slowly.

  A user told me :
  iOS 5 includes a new way to do this fast. The trick is to use AVFoundation and link a Core Video pixel buffer directly to an OpenGL texture.

  My problem now is that my video player send to render method a uint8_t* type that I use then with glTexSubImage2D.

  But if I want to use CVOpenGLESTextureCacheCreateTextureFromImage I need a CVImageBufferRef with the frame.

  The question is : How I can create CVImageBufferRef from uint8_t buffer ?

  This is my render method :

  - (void) render: (uint8_t*) buffer

  
  NSLog(@"render") ;

  [EAGLContext setCurrentContext:context];
  
  
  
  glBindFramebuffer(GL_FRAMEBUFFER, defaultFramebuffer);
  
  glViewport(0, 0, backingWidth, backingHeight);
  
  
  
  glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
  
  
  
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  
  
  
  // OpenGL loads textures lazily so accessing the buffer is deferred until draw; notify
  
  // the movie player that we're done with the texture after glDrawArrays.         
  
  glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, mFrameW, mFrameH, GL_RGB,GL_UNSIGNED_SHORT_5_6_5, buffer);   
  
  
  
  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
  
  
  
  [moviePlayerDelegate bufferDone];
  
  
  
  glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
  
  [context presentRenderbuffer:GL_RENDERBUFFER];

  Thanks,