Newest 'ffmpeg' Questions - Stack Overflow

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• How to get the frame rate in android exoplayer programmatically?

  29 June, by YeJong Choe

  I want to get the live stream frame rate using android exoplayer programmatically. I did try following code to get the frame rate.

         exo_player.addAnalyticsListener(new AnalyticsListener() {
          @Override
          public void onTracksChanged(EventTime eventTime, TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
              if(trackGroups!=null && !trackGroups.isEmpty()){
                  for(int i=0;icode>

  but in my code, i can get -1. this is wrong. Is there a way to get the video frame in exoplayer programmatically?

• Thumbnails from S3 Videos using FFMPEG - "No such file or directory: '/bin/ffmpeg'"

  28 June, by Nico

  I am trying to generate thumbnails from videos in an S3 bucket every x frames by following this documentation: https://aws.amazon.com/blogs/media/processing-user-generated-content-using-aws-lambda-and-ffmpeg/

  I am at the point where I'm testing the Lambda code provided in the documentation, but receive this error in CloudWatch Logs:

  

  Here is the portion of the Lambda code associated with this error:

  

  Any help is appreciated. Thanks!

• How to pass BGR NumPy arrays directly to FFMPEG with CUDA support

  28 June, by Ξένη Γήινος

  I am using cv2 to edit images and create a video from the frames with FFMPEG. See this post for more details.

  The images are 3D RGB NumPy arrays (shape is like [h, w, 3]), they are stored in a Python list.

  Yep, I know cv2 has a VideoWriter and I have used it before, but it is very inadequate to meet my needs.

  Simply put, it can only use an FFMPEG version that comes with it, that version does not support CUDA and uses up all CPU time when generating the videos while not using any GPU time at all, the output is way too big and I can't pass many FFMPEG parameters to the VideoWrite initiation.

  I downloaded precompiled binaries of FFMPEG for Windows with CUDA support here, I am using Windows 10 21H1 x64, and my GPU is NVIDIA Geforce GTX 1050 Ti.

  Anyways I need to mess with all the parameters found here and there to find the best compromise between quality and compression, like this:

  command = '{} -y -stream_loop {} -framerate {} -hwaccel cuda -hwaccel_output_format cuda -i {}/{}_%d.png -c:v hevc_nvenc -preset 18 -tune 1 -rc vbr -cq {} -multipass 2 -b:v {} -vf scale={}:{} {}'
  os.system(command.format(FFMPEG, loops-1, fps, tmp_folder, file_name, quality, bitrate, frame_width, frame_height, outfile))
  

  I need to use exactly the binary I downloaded and specify as many parameters as I can to achieve the optimal result.

  Currently I can only save the arrays to a disk as images and use the images as input of FFMPEG, and that is slow but I need exactly that binary and all those parameters.

  After hours of Google searching I found ffmpeg-python, which seems perfect for the job, and I even found this : I can pass the binary path as an argument to the run function, this

  import ffmpeg
  import io
  
  
  def vidwrite(fn, images, framerate=60, vcodec='libx264'):
      if not isinstance(images, np.ndarray):
          images = np.asarray(images)
      _,height,width,channels = images.shape
      process = (
          ffmpeg
              .input('pipe:', format='rawvideo', pix_fmt='rgb24', s='{}x{}'.format(width, height), r=framerate)
              .output(fn, pix_fmt='yuv420p', vcodec=vcodec, r=framerate)
              .overwrite_output()
              .run_async(pipe_stdin=True, overwrite_output=True, pipe_stderr=True)
      )
      for frame in images:
          try:
              process.stdin.write(
                  frame.astype(np.uint8).tobytes()
              )
          except Exception as e: # should probably be an exception related to process.stdin.write
              for line in io.TextIOWrapper(process.stderr, encoding="utf-8"): # I didn't know how to get the stderr from the process, but this worked for me
                  print(line) # <-- print all the lines in the processes stderr after it has errored
              process.stdin.close()
              process.wait()
              return # cant run anymore so end the for loop and the function execution
  

  However I need to pass all those parameters and possibly many more to the process and I am not sure where these parameters should be passed to (where should stream_loop go? What about hwaccel, hwaccel_output_format, multipass...?).

  How do I properly pipeline a bunch of NumPy arrays to an FFMPEG process spawned by an binary that supports CUDA and pass all sorts of arguments to the initialization of that process?

• FFMPEG C++ select GPU

  28 June, by user4212264

   AVDictionary* options = nullptr;
   av_dict_set(&options, "hwaccel", "cuvid", 0);
   av_dict_set_int(&options, "hwaccel_device", 2, 0);
  

  Even though I specify hwaccel device to be 2, it still runs on GPU 0. How can I fix this?

• ffmpeg -itsoffset does not work on a prores mov

  28 June, by friendlygiraffe

  Using -itsoffset works perfectly in ffmpeg with mp4:

  ffmpeg -i video.mp4 -itsoffset 0.355 -i video.mp4 -map 0:v -map 1:a -c copy -y video_offset.mp4
  

  However, with a prores mov it has no affect, throws no errors either:

  ffmpeg -i proresvideo.mov -itsoffset 0.355 -i proresvideo.mov -map 0:v -map 1:a -c copy -y proresvideo_offset.mov