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• How can I get Python to find ffprobe ?

  4 novembre 2018, par tburrows13

  I have ffmpeg and ffprobe installed on my mac (macOS Sierra), and I have added their path to PATH. I can run them from terminal.

  I am trying to use ffprobe to get the width and height of a video file using the following code :

  import subprocess
  
  import shlex
  
  import json
  
  
  
  
  
  # function to find the resolution of the input video file
  
  def findVideoResolution(pathToInputVideo):
  
      cmd = "ffprobe -v quiet -print_format json -show_streams"
  
      args = shlex.split(cmd)
  
      args.append(pathToInputVideo)
  
      # run the ffprobe process, decode stdout into utf-8 & convert to JSON
  
      ffprobeOutput = subprocess.check_output(args).decode('utf-8')
  
      ffprobeOutput = json.loads(ffprobeOutput)
  
  
  
      # find height and width
  
      height = ffprobeOutput['streams'][0]['height']
  
      width = ffprobeOutput['streams'][0]['width']
  
  
  
      return height, width
  
  
  
  h, w = findVideoResolution("/Users/tomburrows/Documents/qfpics/user1/order1/movie.mov")
  
  print(h, w)

  I am sorry I cannot provide a MCVE, as I didn’t write this code, and I don’t really know how it works.

  It gives the following error :

  Traceback (most recent call last):
  
    File "/Users/tomburrows/Dropbox/Moviepy Tests/get_dimensions.py", line 21, in <module>
  
      h, w = findVideoResolution("/Users/tomburrows/Documents/qfpics/user1/order1/movie.mov")
  
    File "/Users/tomburrows/Dropbox/Moviepy Tests/get_dimensions.py", line 12, in findVideoResolution
  
      ffprobeOutput = subprocess.check_output(args).decode('utf-8')
  
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 626, in check_output
  
      **kwargs).stdout
  
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 693, in run
  
      with Popen(*popenargs, **kwargs) as process:
  
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 947, in __init__
  
      restore_signals, start_new_session)
  
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 1551, in _execute_child
  
      raise child_exception_type(errno_num, err_msg)
  
  FileNotFoundError: [Errno 2] No such file or directory: 'ffprobe'
  
  </module>

  If python is not reading from the PATH file, how can I specify where ffprobe is ?

  Edit :
  It appears the python path is not aligned with my shell path.
  Using os.environ["PATH"]+=":/the_path/of/ffprobe/dir" at the beginning of each program allows me to use ffprobe, but why might my python path not be the same as my shell path ?

• ffmpeg - HDR to SDR - Unable to find a suitable output format for 'format=gbrpf32le'

  17 avril 2020, par Saxon Rix

  I'm on windows 10 using ffmpeg 4.0.2. I found the script for HDR to SDR [here][1], but when I run the script from the bottom of the page :

  



  ffmpeg.exe -i input.mkv -vf zscale=t=linear:npl=100,format=gbrpf32le,
zscale=p=bt709,tonemap=tonemap=hable:desat=0,zscale=t=bt709:m=bt709:r=tv,
format=yuv420p -c:v libx265 -crf 18 -preset slower output.mkv


  



  I get this error :

  



  [NULL @ 0000014588707480] Unable to find a suitable output format for 
'format=gbrpf32le'
format=gbrpf32le: Invalid argument


  



  When I run the first script from the page :

  



  ffmpeg.exe -i input.mkv -vf select=gte(n\,360) -vframes 1 output.png


  



  I get this error :

  



  At line:1 char:41
+ ffmpeg.exe -i Hook.mkv -vf select=gte(n\,360) -vframes 1 output.png
+                                         ~
Missing argument in parameter list.
+ CategoryInfo          : ParserError: (:) [], 
ParentContainsErrorRecordException
+ FullyQualifiedErrorId : MissingArgument
[1]: https://stevens.li/guides/video/converting-hdr-to-sdr-with-ffmpeg/


  



  I'm pretty new to ffmpeg, could someone please explain what is going on ?

  



  Many thanks !

  


• ffmpeg avcodec_find_encoder_by_name failes to find encoder h264_nvenc

  18 septembre 2018, par Yona

  When I run this command "ffmpeg -h encoder=h264_nvenc" in the terminal it gives me the following output
  

  and I am able to use the encoder through the command line interface but it got a problem when I try to run from the following source code.

  #include <iostream>
  
  #include 
  
  #include 
  
  
  
  extern "C"
  
  {
  
  #include <libavcodec></libavcodec>avcodec.h>
  
  #include <libavformat></libavformat>avformat.h>
  
  #include <libavutil></libavutil>imgutils.h>
  
  #include <libavutil></libavutil>mathematics.h>
  
  #include <libavutil></libavutil>opt.h>
  
  #include <libswscale></libswscale>swscale.h>
  
  #include 
  
  }
  
  
  
  int main( int argc, char** argv )
  
  {
  
  
  
      const AVCodec *codec;
  
      AVCodecContext *c= NULL;
  
  
  
      av_register_all();
  
  
  
      std::cout &lt;&lt; "Loading codec" &lt;&lt; std::endl;
  
  
  
  //    codec = avcodec_find_encoder_by_name( "libx264" ); // works
  
      codec = avcodec_find_encoder_by_name( "h264_nvenc" );
  
     // codec = avcodec_find_decoder_by_name( "h264_cuvid" );
  
      if( !codec )
  
      {
  
          throw std::runtime_error( "Unable to find codec!" );
  
      }
  
  
  
      std::cout &lt;&lt; "Allocating context" &lt;&lt; std::endl;
  
  
  
      return 0;
  
  
  
  }</iostream>