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• Conversion from Iphone Core Surface RGB Frame into ffmepg AVFarme

  10 mars 2015, par Raghu

  I am trying to convert Core Surface RGB frame buffer(Iphone) to ffmpeg Avfarme to encode into a movie file. But I am not getting the correct video output (video showing colors dazzling not the correct picture)

  I guess there is something wrong with converting from core surface frame buffer into AVFrame.

  Here is my code :

  Surface *surface = [[Surface alloc]initWithCoreSurfaceBuffer:coreSurfaceBuffer];
  
  [surface lock];
  
  unsigned int height = surface.height;
  
  unsigned int width = surface.width;
  
  unsigned int alignmentedBytesPerRow = (width * 4);
  
  if (!readblePixels) {
  
      readblePixels = CGBitmapAllocateData(alignmentedBytesPerRow * height);
  
      NSLog(@"alloced readablepixels");
  
  }
  
  unsigned int bytesPerRow = surface.bytesPerRow;
  
  void *pixels = surface.baseAddress;
  
  for (unsigned int j = 0; j < height; j++) {
  
      memcpy(readblePixels + alignmentedBytesPerRow * j, pixels + bytesPerRow * j, bytesPerRow);
  
  }
  
  
  
  pFrameRGB->data[0] = readblePixels; // I guess here is what I am doing wrong.
  
  pFrameRGB->data[1] = NULL;
  
  pFrameRGB->data[2] = NULL;
  
  pFrameRGB->data[3] = NULL;
  
  
  
  pFrameRGB->linesize[0] = pCodecCtx->width;
  
  pFrameRGB->linesize[1] = 0;
  
  pFrameRGB->linesize[2] = 0;
  
  pFrameRGB->linesize[3] = 0;
  
  
  
  
  
  sws_scale (img_convert_ctx, pFrameRGB->data, pFrameRGB->linesize,
  
         0, pCodecCtx->height,
  
         pFrameYUV->data, pFrameYUV->linesize);   

  Please help me out.

  Thanks,

  Raghu

• 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.

• Video created via ffmpeg will not play on iPhone 10 or Huawei Android using Chrome

  17 février 2020, par MHatton

  I have created a video from a image and adding an MP3 file. It plays fine on my Moto G Android phone and on my desktop, but a collegue has said it will not play on his iPhone 10 or Huawei Android phone running Chrome.

  Does the following ffmpeg need an extra command adding to make the created MP4 more compatible across devices ?

  ffmpeg -loop 1 -i 6f4aa5dfefc4dd32186f41315ad9d1e2-0.png -i "download.mp3" -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest aw-slide0.mp4