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• avcodec/mpegaudio_parser : Update comment to match code

  19 octobre 2015, par Michael Niedermayer

  avcodec/mpegaudio_parser : Update comment to match code
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/mpegaudio_parser.c

• iOS GPUImage : which AVAssetWriter settings to match 'Constrained Baseline' h.264

  15 août 2014, par sunilr

  I have an iOS app which records video using GPUImage. These videos are stored remotely for viewing by other devices. I’d like the resulting video compression to match the settings which are commonly used in Instagram’s videos. I’ve inspected a number of instagram videos and running ffmpeg -i on them results in :

  Stream #0:0(und) : Video : h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 640x640 [SAR 1:1 DAR 1:1], 1104 kb/s, 29.97 fps, 29.97 tbr, 11988 tbn, 59.94 tbc (default)

  How should i match these ? The current settings i’m using are very close to the GPUImage defaults :

  NSDictionary *videoCleanApertureSettings = [NSDictionary dictionaryWithObjectsAndKeys:
  
                                              [NSNumber numberWithInt:videoSize.width], AVVideoCleanApertureWidthKey,
  
                                              [NSNumber numberWithInt:videoSize.height], AVVideoCleanApertureHeightKey,
  
                                              [NSNumber numberWithInt:0], AVVideoCleanApertureHorizontalOffsetKey,
  
                                              [NSNumber numberWithInt:0], AVVideoCleanApertureVerticalOffsetKey,
  
                                              nil];
  
  
  
  NSDictionary *videoAspectRatioSettings = [NSDictionary dictionaryWithObjectsAndKeys:
  
                                            [NSNumber numberWithInt:1], AVVideoPixelAspectRatioHorizontalSpacingKey,
  
                                            [NSNumber numberWithInt:1], AVVideoPixelAspectRatioVerticalSpacingKey,
  
                                            nil];
  
  
  
  NSMutableDictionary * compressionProperties = [[NSMutableDictionary alloc] init];
  
  [compressionProperties setObject:videoCleanApertureSettings forKey:AVVideoCleanApertureKey];
  
  [compressionProperties setObject:videoAspectRatioSettings forKey:AVVideoPixelAspectRatioKey];
  
  [compressionProperties setObject:[NSNumber numberWithInt: 1100000] forKey:AVVideoAverageBitRateKey];
  
  [compressionProperties setObject:[NSNumber numberWithInt: 16] forKey:AVVideoMaxKeyFrameIntervalKey];
  
  [compressionProperties setObject:AVVideoProfileLevelH264BaselineAutoLevel forKey:AVVideoProfileLevelKey];
  
  
  
  NSMutableDictionary *settings = [[NSMutableDictionary alloc] init];
  
  [settings setObject:AVVideoCodecH264 forKey:AVVideoCodecKey];
  
  [settings setObject:[NSNumber numberWithInt:videoSize.width] forKey:AVVideoWidthKey];
  
  [settings setObject:[NSNumber numberWithInt:videoSize.height] forKey:AVVideoHeightKey];
  
  [settings setObject:compressionProperties forKey:AVVideoCompressionPropertiesKey];

  But when i run ffmpeg -i on the videos created, i get :

  Stream #0:0(und) : Video : h264 (Baseline) (avc1 / 0x31637661), yuv420p, 480x480, 1128 kb/s, SAR 1:1 DAR 1:1, 23.86 fps, 24 tbr, 600 tbn, 1200 tbc (default)

  I’m not sure what the difference is between ’Baseline’ and ’Constrained Baseline’ is, so it may be that the settings i have are adequate (for playback of the video from a remote URL on a mobile device).

  Running an ffmpeg conversion on the file with : ffmpeg -i -profile:v baseline DOES recreate the instagram settings, but i’d like to have this happen on the device if possible.

• compat/w32pthreads : Add return values to match the simulated pthread functions.

  30 septembre 2015, par Matt Oliver

  compat/w32pthreads : Add return values to match the simulated pthread functions.
  

  • [DH] compat/w32pthreads.h