Recherche avancée

Sur d’autres sites (4489)

• Merge remote-tracking branch ’cehoyos/master’

  25 juillet 2013, par Michael Niedermayer

  Merge remote-tracking branch ’cehoyos/master’
  * cehoyos/master :
  
    Show max bitrate for mpeg2 video streams in avcodec_string().
  
    Allow native compilation on the iPhone.
  Merged-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] configure
  • [DH] libavcodec/utils.c

• ffmpeg-Error "Buffer queue overflow, dropping." when merging two videos with delay

  20 septembre 2016, par Stefan Urbansky

  I want to merge two videos (as example the iphone video from https://peach.blender.org/trailer-page/). The videos are placed on an background image with the overlay filter and the second video starts 3 seconds later.

  And I need that the audio is mixed.

  Here is my code :

  ffmpeg \
  
      -loop 1 -i background.png  \
  
      -itsoffset 0  -i trailer_iphone.m4v \
  
      -itsoffset 3  -i trailer_iphone.m4v \
  
      \
  
      -y \
  
      -t 36 \
  
      -filter_complex "
  
          [2:a] adelay=3000 [2delayed];
  
          [1:a][2delayed] amerge=inputs=2 [audio];
  
          [0][1:v] overlay=10:10:enable='between(t,0,33)' [lv1];
  
          [lv1][2:v] overlay=10:300:enable='between(t,0,36)' [video]
  
      " \
  
      \
  
      -threads 0 \
  
      -map "[video]" -map "[audio]" \
  
      -vcodec libx264 -acodec aac \
  
      merged-video.mp4

  I get the error message :

  [Parsed_overlay_3 @ 0x7fe892502ac0] [framesync @ 0x7fe892502b88] Buffer queue overflow, dropping.

  And the merged video has many dropped frames.

  I know that are some other posting with this error message. But the suggested solutions doesn’t work for me.

  How can I fix the problem ?

• 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,