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• Get 'creation_time' of video using ffmpeg and regex

  5 février 2014, par Foysal

  I have a metadata text of a video file which is produced by ffmpeg.

  Metadata:
  
      major_brand     : qt  
  
      minor_version   : 0
  
      compatible_brands: qt  
  
      creation_time   : 2011-09-10 21:44:22
  
      model           : iPhone 4
  
      model-deu       : iPhone 4
  
      encoder         : 4.3.5
  
      encoder-deu     : 4.3.5
  
      date            : 2011-09-10T17:44:22-0400
  
      date-deu        : 2011-09-10T17:44:22-0400
  
      location        : +40.7329-073.9864/
  
      location-deu    : +40.7329-073.9864/
  
      make            : Apple
  
      make-deu        : Apple

  I want to get the *'creation_time'* value using regex of the above text. I am using C#.

• ffmpeg produces mp4 I cannot load on latest Safari on iOS

  28 mars 2016, par Michael Heuberger

  When I encode a video with these ffmpeg parameters (based on images), I cannot play that mp4 it produces on latest Safari (inside a tag) inside my iPhone 6s using the latest iOS too :

  ffmpeg 
  
  -r 15.279071668502123 
  
  -f image2 -thread_queue_size 64 
  
  -i /home/michael-heuberger/abcd/frames/%d.webp 
  
  -y 
  
  -an 
  
  -vcodec libx264 
  
  -vf scale=trunc(iw/2)*2:trunc(ih/2)*2 
  
  -crf 16 
  
  -preset fast 
  
  -profile:v baseline 
  
  -pix_fmt yuv420p 
  
  -loglevel warning 
  
  -movflags faststart 
  
  /home/michael-heuberger/abcd/videomail_good.mp4 

  I think the above parameters should be solid. I am adding baseline and yuv420p, yet no luck on Safari 9. Why ?

  This makes it difficult for me to play videomails recorded on www.videomail.io on iOS devices.

  Am I missing something here ? Already did lots of research and tried various combinations, no luck.

  If you want to reproduce that, easy : just record a video on www.videomail.io and after that, copy the link of the recorded video page to your iPhone or just download it for local investigation.

  Any clues very welcome !

• Can I record a video without using UIImagePickerController ?

  24 mai 2016, par SUKIYAKI

  Can I record a video without using UIImagePickerController ?
  Of course without needing to jailbreak or anything else that would cause the App Store to reject the app.

  I think there is a way to access video device not using UIImagePickerController because these camera applications can record video and work on iPhone 2G/3G which utilizes ffmpeg :

  • iVideoCamera
  • iVidCam

  I pick this code up by googling.

  AVFormatParameters formatParams;
  
  AVInputFormat *iformat;
  
  
  
  formatParams.device = "/dev/video0";
  
  formatParams.channel = 0;
  
  formatParams.standard = "ntsc";
  
  formatParams.width = 640;
  
  formatParams.height = 480;
  
  formatParams.frame_rate = 29;
  
  formatParams.frame_rate_base = 1;
  
  filename = "";
  
  iformat = av_find_input_format("video4linux");
  
  
  
  av_open_input_file(&ffmpegFormatContext,
  
                   filename, iformat, 0, &formatParams);

  This code tell me how to open camera device, but I don’t know device path of iPhone.

  How do iVideoCamera and iVidCam record video ?