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• Display YUV420P video using OpenGLES on iPhone

  25 décembre 2014, par user3487978

  I am writing an app displaying YUV420p video using ffmpeg library on iPhone, every thing works fine, but the OpenGL color is a little strange, see picture, the bellow image is displaying using AVPicture in RGB format, above is using AVPicture in YUV format.
  any ideas ?

  my shader

  varying highp vec2 varTexcoord;
  
  uniform sampler2D SamplerY;
  
  uniform sampler2D SamplerUV;
  
  void main (void)
  
  {
  
      mediump vec3 yuv;
  
      lowp vec3 rgb;
  
      yuv.x = texture2D(SamplerY, varTexcoord).r;
  
      yuv.yz = texture2D(SamplerUV, varTexcoord).rg - vec2(0.5, 0.5);
  
      // Using BT.709 which is the standard for HDTV
  
      rgb = mat3(      1,       1,      1,
  
                  0, -.18732, 1.8556,
  
                  1.57481, -.46813,      0) * yuv;
  
      gl_FragColor = vec4(rgb,1.0);
  
  }

  Renderer :

  glActiveTexture(GL_TEXTURE0);
  
  glTexImage2D(GL_TEXTURE_2D,
  
               0,
  
               GL_LUMINANCE,
  
               (GLsizei)model.width,
  
               (GLsizei)model.height,
  
               0,
  
               GL_LUMINANCE,
  
               GL_UNSIGNED_BYTE,
  
               [model.y bytes]);
  
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  
  
  
  glActiveTexture(GL_TEXTURE1);
  
  glTexImage2D(GL_TEXTURE_2D,
  
               0,
  
               GL_LUMINANCE,
  
               (GLsizei)model.width/2,
  
               (GLsizei)model.height/2,
  
               0,
  
               GL_LUMINANCE,
  
               GL_UNSIGNED_BYTE,
  
               [model.uv bytes]);
  
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  
  glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

  

• Recording MP3 file from iphone using FFMPEG

  16 octobre 2014, par harit shah

  I am trying to record an mp3 file from iphone. It seems it is not possible so next option I am trying is recording it with aac encoding and convert it with ffmpeg exe to mp3.

  I am recording the m4a file with following code :

  // Set the audio file
  
  NSArray *pathComponents = [NSArray arrayWithObjects:
  
                             [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject],
  
                             @"MyAudioMemo.aac",
  
                             nil];
  
  NSURL *outputFileURL = [NSURL fileURLWithPathComponents:pathComponents];
  
  
  
  // Setup audio session
  
  AVAudioSession *session = [AVAudioSession sharedInstance];
  
  [session setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
  
  UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
  
  AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);
  
  
  
  NSMutableDictionary *recordSettings = [[NSMutableDictionary alloc] initWithCapacity:10];
  
  NSNumber *formatObject;
  
  formatObject = [NSNumber numberWithInt: kAudioFormatMPEG4AAC];
  
  
  
  [recordSettings setObject:formatObject forKey: AVFormatIDKey];
  
  [recordSettings setObject:[NSNumber numberWithFloat:44100.0] forKey: AVSampleRateKey];
  
  [recordSettings setObject:[NSNumber numberWithInt:1] forKey:AVNumberOfChannelsKey];
  
  // [recordSettings setObject:[NSNumber numberWithInt:12800] forKey:AVEncoderBitRateKey];
  
  // [recordSettings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
  
  [recordSettings setObject:[NSNumber numberWithInt: AVAudioQualityHigh] forKey: AVEncoderAudioQualityKey];

  so when I try to convert it using ffmpeg -i 1.m4a 1.mp3 it says invalid input found while reading 1.m4a. I tried different encoding but everytime I get the same error. Any help on this would be life saving.

  Thanks.

• ffmpeg image conversion works for nokia conformation heic files but not iphone heic images

  2 novembre 2020, par user12879350

  Below ffmpeg image conversion works for nokia conformation heic files but not iphone heic images

  



  ffmpeg -i c001.heic -c:v mjpeg -frames:v 1 -pix_fmt rgb48 outs.jpg 
(works for nokia conformation files https://github.com/nokiatech/heif_conformance/tree/master/conformance_files 
but not iphone images )

  



  For iphone images ,it throws the below exception
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000021bcaba9980] moov atom not found
image4.heic : Invalid data found when processing input

  



  Is there anything I'm missing