Recherche avancée

Sur d’autres sites (9323)

• Doesn't python's ffmpy works with temporary files made using tempfile.TemporaryFile ?

  8 juin 2017, par tkhurana96

  I am making a function whose purpose is to take a mp3 file and analyse and process it. So, taking help from this SO answer, I am making a temporary wav file, and then using python ffmpy library I am trying to convert mp3(actual given file) to wav file. But the catch is that I am giving the temporary wav file generated above as the output file to ffmpy to store the result to i.e. I am doing this :

  import ffmpy
  
  import tempfile
  
  from scipy.io import wavfile
  
  
  
  # audioFile variable is known here
  
  
  
  tempWavFile = tempfile.TemporaryFile(suffix="wav")
  
  ff_obj = ffmpy.FFmpeg(
  
                        global_options="hide_banner",
  
                        inputs={audioFile:None},
  
                        outputs={tempWavFile: " -acodec pcm_s16le -ac 1 -ar 44000"}
  
                       )
  
  
  
  ff_obj.run()
  
  
  
  [fs, frames] = wavfile.read(tempWavFile)
  
  print(" fs is: ", fs)
  
  print(" frames is: ", frames)

  But on line ff_obj.run() this error occurs :

  File "/home/tushar/.local/lib/python3.5/site-packages/ffmpy.py", line 95, in run
  
      stderr=stderr
  
    File "/usr/lib/python3.5/subprocess.py", line 947, in __init__
  
      restore_signals, start_new_session)
  
    File "/usr/lib/python3.5/subprocess.py", line 1490, in _execute_child
  
      restore_signals, start_new_session, preexec_fn)
  
  TypeError: Can't convert '_io.TextIOWrapper' object to str implicitly

  So, my question is :

  • When I replaced tempWavFile = tempfile.TemporaryFile(suffix="wav") with tempWavFile = tempfile.mktemp('.wav'), no error occurs, why so ?
  • What does this error mean and what is the cause of it’s occurrence and how can it be corrected ?

• ffmpeg remove Non-Monotonous DTS frames

  24 mars, par MiGu3X

  Is it possible to stream copy a .ts file to another .ts file by removing the Non-Monotonous DTS frames ? These frames usually also have a smaller resolution than the video I am trying to copy. I attempted this with VideoReDo but it did not work and I cannot seem to make it work.

  



  Also, the MediaInfo for the video after remixed to Matrosks shows this :

  



  Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L3.2
Format settings                          : CABAC / 2 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 2 frames
Codec ID                                 : V_MPEG4/ISO/AVC
Duration                                 : 2 h 35 min
Nominal bit rate                         : 6 000 kb/s
Width                                    : 896 pixels
Original width                           : 1 280 pixels
Height                                   : 504 pixels
Original height                          : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 30.000 FPS
Original frame rate                      : 60.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.443
Writing library                          : x264 core 148 r2579M 73ae2d1
Encoding settings                        : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=4 / lookahead_threads=1 / sliced_threads=0 / nr=250 / decimate=1 / interlaced=0 / bluray_compat=0 / stitchable=1 / constrained_intra=0 / bframes=0 / weightp=1 / keyint=122 / keyint_min=12 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=2pass / mbtree=1 / bitrate=6000 / ratetol=1.0 / qcomp=0.60 / qpmin=5 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
Default                                  : Yes
Forced                                   : No


  



  Thanks for the help !

  


• FFMPEG Determine average color of an area of a video

  12 novembre 2019, par Naved Khan

  I have a use case where I’d want to insert one of two watermarks - one designed for a dark-ish background, the other for a light background into a video. Let’s say that I’d want to do this on the top right corner of the video.

  How do I determine the average color of the top right section of the video ? Post this, how do I determine which watermark to use by looking at the average color ?

  I have a solution right now where I am taking equally spaced screenshots and then measuring the average color, but it’s excruciatingly slow, especially for longer videos.

  # Calculate average color
  
      black_distances = []
  
      white_distances = []
  
  
  
      movie = FFMPEG::Movie.new(video_file)
  
      (0..movie.duration / 10).each do |second|
  
  
  
        # extract a frame
  
        filename = "tmp/watermark/#{SecureRandom.uuid}.jpg"
  
        movie.screenshot filename.to_s, seek_time: second
  
  
  
        # analyse frame for color distance
  
        frame = MiniMagick::Image.open(filename)
  
        frame.crop('20%x20%+80%+0')
  
        frame.resize('1x1')
  
        pixel = frame.get_pixels.flatten
  
  
  
        distance_from_black = Math.sqrt(((black[0] - pixel[0])**2 + (black[1] - pixel[1])**2 + (black[2] - pixel[2])**2))
  
        distance_from_white = Math.sqrt(((white[0] - pixel[0])**2 + (white[1] - pixel[1])**2 + (white[2] - pixel[2])**2))
  
  
  
        black_distances.push distance_from_black
  
        white_distances.push distance_from_white
  
  
  
        File.delete(filename) if File.exist?(filename)
  
      end
  
  
  
      average_black_distance = black_distances.reduce(:+).to_f / black_distances.size
  
      average_white_distance = white_distances.reduce(:+).to_f / white_distances.size

  I am also confused about how to use the resulting average_black_distance and average_white_distance to determine which watermark to use.