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• FFMPEG integration on iphone/ ipad project

  12 avril 2020, par Chandramani

  Can any One Tell me how do i integrate FFMPEG in my iphone/ ipad project.i m using Xcode 4.
i searched a lot but did not find any useful Link .please tell me step by step procedure to integrate FFMpeg in my project.

  



  thanks,

  


• ffmpeg can't read png data on iphone

  10 octobre 2014, par user2789801

  I’m using ffmpeg to decode a png picture and use the AVFrame as a opengl texture.
  But the strangest thing is that I can get the png converted to opengl texture nicely on a iphone simulator, but I got a blank texture on a real iphone.

  on both simulator and iphone, I got a null pointer for AVFrame’s data

  avcodec_decode_video2(codecContext/* AVCodecContext* */,frame /* AVFrame */,&finished,&tempPacket); 

  Then I covert the color space to AV_PIX_FMT_RGBA

  void convertToRGBColor()
  
  {
  
      int numBytes = avpicture_get_size(
  
                                    AV_PIX_FMT_RGBA,
  
                                    codecContext->width,
  
                                    codecContext->height);
  
      uint8_t *buffer = (uint8_t *)av_malloc(numBytes);
  
      avpicture_fill(rgbFrame/* AVFrame* */, buffer, AV_PIX_FMT_RGBA, codecContext->width, codecContext->height);
  
  
  
      struct SwsContext *img_convert_ctx = NULL;
  
      img_convert_ctx = sws_getCachedContext(
  
                           img_convert_ctx,
  
                           codecContext->width,
  
                           codecContext->height,
  
                           codecContext->pix_fmt,
  
                           codecContext->width,
  
                           codecContext->height,
  
                           COLOR_SPACE,
  
                           SWS_BILINEAR,
  
                           NULL,
  
                           NULL,
  
                           NULL);
  
  
  
      if( !img_convert_ctx )
  
      {
  
          fprintf(stderr, "Cannot initialize sws conversion context\n");
  
      }
  
  
  
      sws_scale(img_convert_ctx,
  
                frame->data,
  
                frame->linesize,
  
                0,
  
                codecContext->height,
  
                rgbFrame->data,
  
                rgbFrame->linesize);
  
      sws_freeContext(img_convert_ctx);
  
  }

  On a simulator, rgbFrame’s data[0] will be a valid pointer, but on a iphone, it’s null.

  So, does anyone had the same problem before ?

• iPhone slow motion video transcode

  25 mai 2016, par coverboy

  I’m developing upload video (taken from iPhone) to my server.

  However, I have no idea how to implement.

  Any source code objective-c or swift will be welcomed.

  I have 120fps or 240fps video (It’s a slo-mo).
  When I playback these video on my iPhone6. I can see slo-mo effect.
  (I know playback frame rate is 30fps.)

  I want to convert that video before upload to my server, from 120/240 fps to 30fps video. (I mean not adjusting playback frame rate, it means video transcode to 30fps.)
  Additionally, I want to check slo-mo effect start-point and end-point.
  (Maybe iPhone record this information to video binary(it might be reside in file’s header.)

  Well, I guess if I use ffmpeg library, it should be easy(?).

  So any suggestions will be welcomed.