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• cvCreateFileCapture always returns "NULL"

  4 août 2012, par user1553247

  I am making an iphone-app with Xcode 4.3.3 and OpenCV 2.4

  I used that "cvCreateFileCapture("simtom.mp4")" to get frame from '.mp4' file but unfortunately, cvCreateFileCapture() always returns "NULL".

  What is the problem ?

  Here is my source code.

   CvCapture *m_pMusicVideo;     
  
  
  
   m_pMusicVideo = cvCreateFileCapture("simtom.mp4");

• 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,

• trying to build a audio video format convertion tool help required

  19 février 2012, par moon

  hello i am going to build a windows desktop tool that can convert the audio and video formats of all types.

  i am in technology selection phase.

  thinking about java and ffmpeg for this purpose but i come to know there are some formats that ffmpeg can not convert for them what should i do ?

  second is there ffmpge api for java to use intead of using it through process builder ?

  and at last is there any other approach that is more easy and stable from described above ?

  AVI, MPG, MPEG, VOB, WMV, MP4, M4V,

  ASF, MOV, QT, 3GP, DAT, OGM, DVR-MS, FLV, MKV, RM, RMVB, VRO, TS, AMV,
  F4V, MTS, MT2S, WAV, MP3, WMA, OGG, APE,

  M4A, MPC, WV, AMR, AC3, AU to AVI, MPEG, MOV, WMV, MP4, RM, iPod,
  iPad, HTC, PSP, iPhone, Zune, BlackBerry, Apple

  TV, PS3, Xbox360, Creative ZEN, Archos, iRiver, 3GP, FLV, SWF, WAV,
  MP3, WMA, M4A, AMR, AAC, AIFF and AC3

  help required

  regards.