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• How to deal ffplay bein too slow playing iPhone's videos ?

  21 janvier 2019, par Mikhail T.

  Trying to play a 3840x2160 video recorded by an iPhone 7 (@30fps), I get frequent pauses — in the video, music keeps playing.

  This happens both in firefox and when ffplay is invoked to play the file directly — from command-line. The CPU is a dual E6700 @3.20GHz — not super fast, but it should be able to play smoothly, shouldn’t it ? Video is Intel’s "series 4" integrated chipset — again, not a speed-daemon, but it should be adequate... Support for Intel’s VA API is included.

  I build ffmpeg-4.1 from source using FreeBSD port. As you can see, the port has a maddening amount of options — including several different ones for the 264-codec.

  Any suggestions for improving the decoding speed to the point, where it is watchable by a human ? Thank you !

• FFMPEG for iPhone recorded video encoding

  16 décembre 2011, par Sarah

  Hi found lots and lots of links for video encoding through ffmpeg 1,2,3,4 etc but they all start with using terminal commands but when i try to implement any on terminal like :

  git clone git ://github.com/lajos/iFrameExtractor.gitit says that-bash : git : command not found.

  Also as per my knowledge it is not possible to use terminal command on iPhone. Can anybody point out how to encode a video recorded through ffmpeg in mp4 format and also to reduce the size of the video ?Thanks in advance.

  EDIT :
  I am already implementing this method to resize my video and it successfully takes place and I am able to send the video on server but then on server side it's giving problem in retrieving the data and to use it.

  - (void)imagePickerController:(UIImagePickerController *)picker 
  
  didFinishPickingMediaWithInfo:(NSDictionary *)info
  
  {
  
      [self convertVideoToLowQuailtyWithInputURL:videoURL1 outputURL:[NSURL fileURLWithPath:videoStoragePath] handler:^(AVAssetExportSession *exportSession)
  
       {
  
           if (exportSession.status == AVAssetExportSessionStatusCompleted)
  
           {
  
               NSLog(@"%@",exportSession.error);
  
               printf("completed\n");
  
           }
  
           else
  
           {
  
               NSLog(@"%@",exportSession.error);
  
               printf("error\n");
  
           }
  
       }];
  
  }
  
  
  
  - (void)convertVideoToLowQuailtyWithInputURL:(NSURL*)inputURL 
  
                                     outputURL:(NSURL*)outputURL 
  
                                       handler:(void (^)(AVAssetExportSession*))handler
  
  {
  
      [[NSFileManager defaultManager] removeItemAtURL:outputURL error:nil];
  
      AVURLAsset *asset = [AVURLAsset URLAssetWithURL:inputURL options:nil];
  
      AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetLowQuality];
  
      exportSession.outputURL = outputURL;
  
      exportSession.outputFileType = AVFileTypeQuickTimeMovie;
  
      [exportSession exportAsynchronouslyWithCompletionHandler:^(void) 
  
       {
  
           handler(exportSession);
  
           [exportSession release];
  
       }];
  
  }

• Cannot play DAV to MP4 converted H.265 video file with hvc1 tag in iPhone

  21 août 2023, par Venkata Subbarao

  I have converted H.265 video file in dav format from Dahua camera using following commands. Both of the generated mp4 video files are NOT playable in iPhone default player. However, the generated video files are playable in VLC player.

  


  ffmpeg -y -i hevc.dav -c:v copy -tag:v hvc1 hevc.mp4
ffmpeg -y -i hevc.dav -tag:v hvc1 -c:v copy -f mp4 -movflags frag_keyframe+empty_moov hevc.mp4


  


  Generated video file plays only if I re-encode the video using following command.

  


  ffmpeg -y -i hevc.dav -c:v libx265 -tag:v hvc1 hevc.mp4


  


  Re-encoding is time consuming. So, please let me know, if I am missing any flags in the above commands.