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• Return multiple parameters in Python

  7 mars 2018, par Georgе Stoyanov

  I am trying to re-write one of my scripts using functions. It is analyzing couple of transport stream files in a directory and then returns the GoP size of all TS files using ffprobe and writes the json file to the log directory. So this is originally my script and it works just fine :

  #!/usr/bin/env python
  
  import subprocess
  
  import json
  
  import os.path
  
  
  
  recdir = "/home/user/recordings/"
  
  logdir = "/home/user/logs/"
  
  
  
  
  
  for input_file in os.listdir(recdir):
  
          gop_list = []
  
          p = 0
  
          fname = os.path.splitext(input_file)[0]
  
          if input_file.endswith(".ts"):
  
                  abs_file = recdir + "/" + input_file
  
                  # Execute the ffprobe command for analysing the GoP Structure
  
                  gop_data = subprocess.check_output(['ffprobe', '-v', 'quiet', '-read_intervals', "%+10", '-print_format', 'json', '-select_streams', 'v', '-show_frames', '-show_entries', 'frame=coded_picture_number,key_frame,pict_type', abs_file])
  
  #               print gop_data
  
                  # Write output to a file
  
                  out = open("{}_gop_data.json".format(fname), "w+")
  
                  out.write(gop_data)
  
                  out.close
  
                  #End of writing
  
                  # Loading the json file
  
                  gop = json.loads(gop_data.decode('utf-8'))
  
                  print "-------------------------- GoP information for {} ------------------------------".format(input_file)
  
                  print
  
                  # Calculating the GoP length of the video(difference between two IDR frames)
  
                  for i in range(len(gop["frames"])):
  
                          if (gop["frames"][i]["pict_type"]) == "I" and (gop["frames"][i]["key_frame"] == 1):
  
                                  gop_list.append(i)
  
                                  p += 1
  
                          # Printing the first 5 results if present
  
                  for r in range(1, p):
  
                          print "GoP frame length Nr: {0} is: {1}".format(r, (gop_list[r] - gop_list[r-1] + 1))
  
                  print
  
  
  
                  for i in range(len(gop["frames"])):
  
                          if (gop["frames"][i]["pict_type"]) == "I" and (gop["frames"][i]["key_frame"] == 1):
  
                                  gop_list.append(i)
  
                                  p += 1

  I want to create 3 functions out of it. One is to execute the ffprobe command and to save the output to a variable "gop". Another one is to write the json output to different files and the third is to present the data to the command line. The problem currently is that the first function is returning the gop parameter but it returns only the last one. Please keep in mind that these files are quite big. So I think I need to return the name of the file and the corresponding GoP file at the same time and use this data for the other two functions (write_gop_data and iframe_calculator) but I am not sure how I can do that.

  #!/usr/bin/env python
  
  import subprocess
  
  import json
  
  import os.path
  
  
  
  recdir = "/home/user/recordings/"
  
  logdir = "/home/user/logs/"
  
  
  
  def reading_gop_data(input_directory):
  
          for input_file in os.listdir(input_directory):
  
                  fname = os.path.splitext(input_file)[0]
  
                  if input_file.endswith(".ts"):
  
                          abs_file = recdir + input_file
  
                          # Execute the ffprobe command for analysing the GoP Structure
  
                          gop = subprocess.check_output(['ffprobe', '-v', 'quiet', '-read_intervals', "%+10", '-print_format', 'json', '-select_streams', 'v', '-show_frames', '-show_entries', 'frame=coded_picture_number,key_frame,pict_type', abs_file])
  
                          return gop
  
  
  
  def write_gop_data(gop_data, input_directory, save_directory):
  
          for input_file in os.listdir(input_directory):
  
                  fname = os.path.splitext(input_file)[0]
  
                  out = open("{}{}_gop.json".format(save_directory, fname), "w+")
  
                  out.write(gop_data)
  
                  out.close
  
  
  
  def iframe_calculator(gop_data, input_directory):
  
          for input_file in os.listdir(input_directory):
  
                  gop_list = []
  
                  p = 0
  
                  if input_file.endswith(".ts"):
  
                          gop_json = json.loads(gop_data.decode('utf-8'))
  
                          print "-------------------------- GoP information for {} ------------------------------".format(input_file)
  
                          print
  
                          # Calculating the GoP length of the video(difference between two IDR frames)
  
                          for i in range(len(gop_json["frames"])):
  
                                  if (gop_json["frames"][i]["pict_type"]) == "I" and (gop_json["frames"][i]["key_frame"] == 1):
  
                                          gop_list.append(i)
  
                                          p += 1
  
                          # Printing the first 5 results if present
  
                  for r in range(1, p):
  
                          print "GoP frame length Nr: {0} is: {1}".format(r, (gop_list[r] - gop_list[r-1] + 1))
  
                  print
  
  
  
  
  
  # reading_gop_data(recdir)
  
  write_gop_data(reading_gop_data(recdir), recdir, logdir)
  
  iframe_calculator(reading_gop_data(recdir), recdir)

• lavc/vaapi_encode : Don't return error if the underlying driver doesn't support B...

  6 février 2018, par Haihao Xiang

  lavc/vaapi_encode : Don't return error if the underlying driver doesn't support B frames
  The underlying driver need not support B frames - since they are enabled
  
  by default for some codecs, it is better to disable them rather than
  
  returning an error in this case.  This makes the default settings usable
  
  for low-power encoding on Intel platforms.
  Signed-off-by : Haihao Xiang <haihao.xiang@intel.com>
  
  Signed-off-by : Mark Thompson <sw@jkqxz.net>
  

  • [DH] libavcodec/vaapi_encode.c

• How to return width and height of a video/image using ffprobe & batch

  7 octobre 2023, par user780756

  I need to get the width and height of an image file using ffprobe and need to store it in variables using batch (Windows) so I can later use those values.

  



  I tried to do this,

  



  @echo off
for /f "tokens=1-2" %%i in ('ffprobe -v error -of flat=s=_ -select_streams v:0 -show_entries stream=width,height %1') do set W=%%i & set H=%%j
echo %W%
echo %H%


  



  But fails to execute with

  



  Argument '_' provided as input filename, but 's' was already specified.


  



  p.s. I also tried imagemagick identify in a similar way, but it seems that identify has a bug when returning height for GIF files