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• How to fetch video frame and its timestamp from ffmpeg to python code

  14 février 2017, par vijiboy

  Searching for an alternative as OpenCV would not provide timestamps which were required in my computer vision algorithm, I found this excellent article https://zulko.github.io/blog/2013/09/27/read-and-write-video-frames-in-python-using-ffmpeg/
  Working up the code on windows I still could’nt get the frame timestamps.
  I recollected seeing on ffmpeg forum somewhere that the video filters like showinfo are bypassed when redirected.

  Here’s what I tried :

  import subprocess as sp
  
  import numpy
  
  import cv2
  
  
  
  command = [ 'ffmpeg', 
  
              '-i', 'e:\sample.wmv',
  
              '-pix_fmt', 'rgb24',
  
              '-vcodec', 'rawvideo',
  
              '-vf', 'showinfo', # video filter - showinfo will provide frame timestamps
  
              '-an','-sn', #-an, -sn disables audio and sub-title processing respectively
  
              '-f', 'image2pipe', '-'] # we need to output to a pipe
  
  
  
  pipe = sp.Popen(command, stdout = sp.PIPE, stderr = sp.STDOUT) # TODO someone on ffmpeg forum said video filters (e.g. showinfo) are bypassed when stdout is redirected to pipes??? 
  
  
  
  for i in range(10):
  
      raw_image = pipe.stdout.read(1280*720*3)
  
      img_info = pipe.stdout.read(244) # 244 characters is the current output of showinfo video filter
  
      print "showinfo output", img_info
  
      image1 =  numpy.fromstring(raw_image, dtype='uint8')
  
      image2 = image1.reshape((720,1280,3))  
  
  
  
      # write video frame to file just to verify
  
      videoFrameName = 'Video_Frame{0}.png'.format(i)
  
      cv2.imwrite(videoFrameName,image2)
  
  
  
      # throw away the data in the pipe's buffer.
  
      pipe.stdout.flush()

  So how to still get the frame timestamps from ffmpeg into python code so that it can be used in my computer vision algorithm ...

• Batch file : FOR loop not working to concatenate mp3 and mp4

  7 janvier 2023, par Ionut Bejinariu

  mp3list-1.txt contain the full patch to the mp3 files that will be concatenated

  


  mp4list-1.txt contain full path to the mp4 files that will be concatenated

  


  then both results mergedmp34.mp3 and mergeMp4.mp4 should be combined together in a final MP4 video file with a random name.

  


  something I do wrong I don't understand what

  


  my guess I do something wrong on FOR loop.

  


  sometimes my .txt files contain full path to a single file mp4 or mp3

  


  if don't have what to combine will concatenate 1 single file ?

  


  set exportdir=
set batsource= the place where this batch file is

1< mp3list-1.txt 2< mp4list-1.txt (
    FOR %%A in ("%batsource%") DO (
        set /p mp3list=" <&1
        set /p mp4list=" <&2
        ffmpeg -f concat -safe 0 -i "!mp3list!" -c copy mergedmp34.mp3
        ffmpeg -f concat -safe 0 -i "!mp4list!" -c copy mergeMp4.mp4
        ffmpeg -i mergedmp34.mp3 -i mergeMp4.mp4 -map 0:v -map 1:a -vcodec copy -c:a aac -b:a 320k "%exportdir%\%RANDOM%.mp4"
        del mergedmp34.mp3
        del mergeMp4.mp4
 
         
    )
)



  


  mp4list-1.txt

  


  F:\.....Videos-115\output-mp4.txt
F:\....\Videos-1150\output-mp4.txt
F:\.....\Videos-1151\output-mp4.txt
F:\......Videos-1152\output-mp4.txt


  


  mp3list-1.txt

  


  F:\......audio-52\output-mp3.txt



  


  and .txt with direct files are like :

  


  file 'F:\....00OH7011.mp3'
file 'F:\....00OH7011.mp3'
file 'F:\....00OH7011.mp3'


  


  and for videos

  


  file 'F:\....00OH7011.mp4'
file 'F:\....00OH7011.mp4'
file 'F:\....00OH7011.mp4'


  


  Later Edit
basically, I want to adapt to my needs the above script based on this working script bellow where I have 4 txt files that are looped.

  


  mkdir ".\Export"
set "sourcedir="  
set "outputdir=Export"

1< codfundal.txt 2< fontalbum.txt 3< album.txt 4< artist.txt (for %%F in (*.jpg *.jpeg) do (
set /P "artist=" <&4 
set /P "fontalbum="<&2  
set /P "album=" <&3
set /P "codfundal=" <&1
   
   
   magick convert -gamma 1 -contrast 30 %%F -fill white -undercolor  "!codfundal!"  -gravity Center -font "!fontalbum!" -pointsize 215   -annotate +0+5  "!album!"  -gravity Center -pointsize 120 -font "Calibri-Bold" -annotate +0+220 "!artist!" -crop 1440x1440+0+0   -quality 92 "%outputdir%\%%F" 




    )
)


  


  album.txt

  


  Circumferential
Genealogy
Iraqi
Fitters


  


  artist.txt

  


  Bhaskar Punk
Costas Fourie
Sonja Bryan
Jin Gullberg



  


  codfundal.txt

  


  
#E70E0E
#ff00ff
#993366
#99cc00
#cc99ff


  


  fontalbum.txt

  


  Bauhaus-93
Agency-FB
Bernard-MT-Condensed
Bodoni-MT


  


• ffv1/vulkan : redo context count tracking and quant_table_idx management

  5 avril, par Lynne

  ffv1/vulkan : redo context count tracking and quant_table_idx management
  This commit also makes it possible for the encoder to choose a different
  
  quantization table on a per-slice basis, as well as adding this capability
  
  to the decoder.
  Also, this commit fully fixes decoding of context=1 encoded files.
  

  • [DH] libavcodec/ffv1_vulkan.h
  • [DH] libavcodec/ffv1enc_vulkan.c
  • [DH] libavcodec/vulkan/ffv1_common.comp
  • [DH] libavcodec/vulkan/ffv1_dec.comp
  • [DH] libavcodec/vulkan/ffv1_dec_setup.comp
  • [DH] libavcodec/vulkan/ffv1_enc_setup.comp
  • [DH] libavcodec/vulkan/ffv1_reset.comp
  • [DH] libavcodec/vulkan_ffv1.c