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• Achieving very poor fps for my iphone app for decode + display h264 frames using ffmpeg and opengl

  29 décembre 2015, par sam18

  I have three steps process for my application which display h264 frame on iPhone screen.

  1. decode using ffmpeg.
  2. scale and colorspace conversion (scale to 256 X 256 Opengl ES 1 texture and convert colospace from yuv420p to rgb565 using sws_Scale from ffmpeg).
  3. Render opengl 1 texture to frame buffer to render buffer

  after these three step process, I got my picture on iPhone screen.

  When I was testing the performance for 720 X 576 resolution frames, I obtain very poor FPS. It is reaching max to 180 milliseconds and hence resulting into 5 to 6 FPS.

  Any direction will be grateful.

• video frames render slow using opengl and ffmpeg in iphone

  17 février 2012, 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 app is very slow render the frames and some videos played slowly.

  I have played AVI, MOV, FLV, MP4 and WMV, and only several AVI files are correct played.

  I don't have much idea of ffmpeg and opengl, and I have used a tutorials and examples until now. But I think that the problem can be two things :

  1. The render method is very slowly. I don't use correctly the glTexSubImage2D function.

  2. I don't scale the frames correctly. I don't use correctly the sws_getContext function.

  I'm here parts of my code, to see if anyone can help me.

  So I use sws_getContext

   ctx->p_sws_ctx = sws_getContext(ctx->p_video_ctx->width, 
  
                                  ctx->p_video_ctx->height, 
  
                                  ctx->p_video_ctx->pix_fmt, 
  
                                  ctx->p_video_ctx->width, 
  
                                  ctx->p_video_ctx->height,
  
                                  PIX_FMT_RGB565, SWS_FAST_BILINEAR, NULL, NULL, NULL);
  
  
  
  
  
  
  
  
  
  // Framebuffer for RGB data
  
  ctx->p_frame_buffer = malloc(avpicture_get_size(PIX_FMT_RGB565,
  
                                                  ctx->p_video_ctx->width, 
  
                                                  ctx->p_video_ctx->height));
  
  
  
  avpicture_fill((AVPicture*)ctx->p_picture_rgb, ctx->p_frame_buffer, PIX_FMT_RGB565, 
  
                 ctx->p_video_ctx->width, 
  
                 ctx->p_video_ctx->height);

  My render method of opengl 2.0

  - (void) render: (uint8_t*) buffer

  [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];

  Someone, can I Help me ?

  Thanks,

• compiling ffmpeg for iPhone SDK 4.3 [error : is unable to create an executable file.]

  12 février 2012, par user509020

  Like many others.. I'm compiling ffmpeg using gas preprocessor

  http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2009-October/077701.html

  This is my command

  ./configure --cc=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/arm-apple-darwin10-gcc-4.2.1 --as='gas-preprocessor.pl /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/arm-apple-darwin10-gcc-4.2.1' --sysroot=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk --enable-cross-compile --target-os=darwin --arch=arm7 --cpu=cortex-a8 --enable-pic

  the error :

  /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/arm-apple-darwin10-gcc-4.2.1 is unable to create an executable file.
  
  C compiler test failed.

  I looked up the /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/ folder using Finder..
  arm-apple-darwin10-gcc-4.2.1 was there..

  Thanks,
  Suhas