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• avfoundation : Fix compilation for OSes other than macOS and iOS

  25 mars, par Martin Storsjö

  avfoundation : Fix compilation for OSes other than macOS and iOS
  E.g. tvOS doesn't have devicesWithMediaType.
  In principle, we could probably disable building the whole
  
  input device on such OSes, but that would either require
  
  testing explicitly for the OS type in configure (which we don't
  
  do anywhere so far), or test for individual objective C methods.
  This approach allows the code to compile, but no input devices
  
  will be found at runtime.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libavdevice/avfoundation.m

• Real time compression/encoding using ffmpeg in objective c

  20 février 2014, par halfwaythru

  I have a small application written in Objective-c that looks for the video devices on the machine and allows the user to record video. I need to be able to compress this video stream in real time. I do not want to save the whole video, I want to compress it as much as possible and only write out the compressed version.

  I also don't want to use the AVFoundation's build in compression methods and need to use a third party library like ffmpeg.

  So far, I have been able to record the video and get individual frames using 'AVCaptureVideoDataOutputSampleBufferDelegate' in this method :

  - (void)captureOutput:(AVCaptureOutput *)captureOutput
  
     didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
  
     fromConnection:(AVCaptureConnection *)connection

  So I have a stream of images basically, and I want to throw them into ffmpeg (which is all set up on my machine). Do I need to call a terminal command to do this ? And if I do, how do I use the image stack as my input to the ffmpeg command, instead of the video. Also, how do I combine all the little videos in the end ?

  Any help is appreciated. Thanks !

• FFmpeg : Pipe segments to s3

  24 septembre 2024, par Brendan Kennedy

  I'd like to pipe ffmpeg segments to s3 without writing them to disk.

  


  ffmpeg -i t2.mp4 -map 0 -c copy -f segment -segment_time 20 output_%04d.mkv


  


  Is it possible to modify this command so that ffmpeg writes segments to an s3 bucket ? Something like this perhaps ?

  


  ffmpeg -i t2.mp4 -map 0 -c copy -f segment -segment_time 20 pipe:1 \
  | aws s3 cp - s3://bucket/output_%04d.mkv


  


  When I run the command above I receive this error

  


  Could not write header for output file #0
(incorrect codec parameters ?): Muxer not found


  


  This command works except the entire video is uploaded and not the individual segments

  


  ffmpeg -i t2.mp4 -map 0 -c copy -f segment -segment_time 20 pipe:output_%04d.mkv \
| aws s3 cp - s3://bucket/test.mkv