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• BGRA to AVFrame(ffmpeg) and viceversa ? for IOS

  8 février 2012, par Asta ni enohpi

  Am working Video Processing in IOS(iphone/ipod/ipad) Using Objective c. i am using AVFoundation Framework to Capture Video . i want to Encode/decode those video frame using ffmpeg-libx264. i have compiled ffmpeg-x264 lib for ios. i got kCVPixelFormatType_32BGRA from AVFoundation.

  my problem is
  1.How to convert kCVPixelFormatType_32BGRA to AVFrame for enode using avcodec_encode_video ?

  2.How to convert AVFrame to kCVPixelFormatType_32BGRA @ decode side from avcodec_decode_video2 ?

  Please help me to start above process or give path for working tutorial .Thanks in advance.

• what is the best open source framework for programmatically producing .mov or .flv video files ? [closed]

  12 mai 2013, par Andrew Arrow

  I would like to programmatically produce a simple animation video. Don't think "Toy Story" level of animation, think simple stick figures moving around the screen and other very simple lines and dots in black and white only. The point of the video is to explain a complicated scientific concept with a 5 minute video vs. pages and pages of text trying to describe images with words.

  What is the best open source framework to make a .mov or .flv file that I can then upload to youtube or vimeo. I could use ImageMagick to write out jpeg after jpeg, and then ffmpeg to turn those jpegs into a .mov file. But is there a better framework out there for simple animation like this ? I feel like the ImageMagick to ffmpeg route is going to involve a lot of me writing code from scratch to make a stick figure walk across the screen.

• OpenGL ES glReadPixels exc_bad_access

  6 décembre 2011, par Yanny

  I'm trying to create video from images using OpenGL ES and ffmpeg, but on iPad(4.3) I have a crash on glReadPixels

  -(NSData *) glToUIImage {
  
  
  
      int numberOfComponents = NUMBER_OF_COMPONENTS; //4
  
      int width = PICTURE_WIDTH; 
  
      int height = PICTURE_HEIGHT;
  
  
  
      NSInteger myDataLength = width * height * numberOfComponents;   
  
  
  
      NSMutableData * buffer= [NSMutableData dataWithLength :myDataLength];    
  
  
  
      [self checkForGLError]; 
  
  
  
      GLenum type = NUMBER_OF_COMPONENTS == 3 ? GL_RGB : GL_RGBA; //RGBA
  
      glReadPixels(0, 0, width, height, type, GL_UNSIGNED_BYTE, [buffer mutableBytes]);   //EXC_BAD_ACCESS here
  
  
  
      return buffer; 
  
  }

  It is working on iPhone 4 (4.3) and iPod Touch, but have problems on iPhone 3G(3.0) and iPad(4.3). Can you help me with this issue ?

  Also on iPhone 3G(3.0) and iPad(4.3) I have problems with Video - first 5-20 video frames have trash. Maybe issue with optimization ? Or architecture ?

  EDITED
  Stack :

  #0  0x33be3964 in void BlockNxN<64ul, 16ul, 1, BLOCK_CONVERTER_NULL_32>(unsigned long, int, int, unsigned long, int, int, unsigned int, unsigned int, unsigned int, unsigned int) ()
  
  #1  0x33be1c76 in glrBIFDetile ()
  
  #2  0x33b586b2 in sgxGetImage(SGXImageReadParams const*) ()
  
  #3  0x33b50d38 in gldReadPixels ()
  
  #4  0x31813e16 in glReadPixels_Exec ()
  
  #5  0x31e3c518 in glReadPixels ()