Myujth

We are trying to export videos and maintain their FPS. What is happening:

For 1 second video clip example:

• regular motion videos shot at 30 FPS - export at 30 FPS - 30 frames
  total


• regular motion videos shot at 60 FPS - export at 30 FPS -
  30 frames total


• slow motion videos set in camera roll to play in slow motion, export
  at 30 fps - but export every frame to cover the longer play period
  (e.g., 1 second video at 240 fps exports 8 seconds of video at 30
  fps) - so 120 or 240 total


• slow motion videos (120 or 240) set to play in native speed (or 1
  second) - export at 30 fps - 30 frames total

What we want - export to match camera roll FPS in all cases. We are also compressing videos.

We have tried to solve unsuccessfully by reviewing these and others:

How do I control AVAssetWriter to write at the correct FPS

How to set expected framerate to AVAssetWriterInput

I'm guessing we may need an entirely different approach - haven't been able to solve - here is code used to try to upload a 240 fps video that is set to play it native speed - result is a 30 fps 1 second video (instead of 240 fps 1 second video):

 PHVideoRequestOptions *options = [PHVideoRequestOptions new];
 options.version = PHVideoRequestOptionsVersionCurrent;

 [[PHImageManager defaultManager] requestAVAssetForVideo:_phasset options:options resultHandler:^(AVAsset * _Nullable asset, AVAudioMix * 

 _Nullable audioMix, NSDictionary * _Nullable info) 

 
 if(([asset isKindOfClass:[AVComposition class]] && ((AVComposition *)asset).tracks.count == 2)) 
 SDAVAssetExportSession *encoder = [[SDAVAssetExportSession alloc] initWithAsset:asset];
 encoder.outputFileType = AVFileTypeQuickTimeMovie;
 encoder.outputURL = url;
 encoder.videoSettings = @
 
 AVVideoCodecKey: AVVideoCodecH264,
 AVVideoWidthKey: [NSNumber numberWithInteger:newWidth],
 AVVideoHeightKey: [NSNumber numberWithInteger:newHeight],
 AVVideoCompressionPropertiesKey: @
 
 // AVVideoAverageBitRateKey: [NSNumber numberWithInteger:bitrate * 1024],
 AVVideoAverageBitRateKey: [NSNumber numberWithInteger:bitrate * 1024],
 AVVideoProfileLevelKey: AVVideoProfileLevelH264High40,
// AVVideoMaxKeyFrameIntervalKey: [NSNumber numberWithInt:240],
 AVVideoExpectedSourceFrameRateKey: [NSNumber numberWithInteger:240]
 ,
 ;

 encoder.audioSettings = @
 
 AVFormatIDKey: @(kAudioFormatMPEG4AAC),
 AVNumberOfChannelsKey: @1,
 AVSampleRateKey: @44100,
 AVEncoderBitRateKey: @128000,
 ;

 [encoder exportAsynchronouslyWithCompletionHandler:^
 if (encoder.status == AVAssetExportSessionStatusCompleted) 
 NSURL *URL = encoder.outputURL;
 // exported video's fps is not 240 fps on here
 
 ];
 else 
 …
 

Any suggestions on how to fix current code - or how to approach in a different way that works?