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• Using FFmpeg concat filter instead of protocol, differrent results [duplicate]

  18 novembre 2015, par f.rodrigues

  This question already has an answer here :

  • Concatenate two mp4 files using ffmpeg
    
    8 answers
    

  I have two files that need to be merged.

  I can do this using the ffmpeg concat protocol

  creating a text file and setting the files in there.

  Like so :

  files_to_be_merged.txt

  file '/home/user/Videos/video1.mov'
  
  file '/home/user/Videos/video2.mov'

  and them using the following command.

  ffmpeg -f concat -i mylist.txt -c copy output.mov

  But I want to do that without having to create a text file.

  I tried this command :

  ffmpeg -i 'concat:video1.mov|video2.mov' -codec copy output.mov

  But the resulting file is just the first video, not both together.

  I get this warning while doing this command ;

  [mov @ 0x35933c0] Codec for stream 0 does not use global headers but
  container format requires global headers

  [mov @ 0x35933c0] Codec for stream 1 does not use global headers but
  container format requires global headers

• Pushing on-fly transcoded video to embeded http results with no seekbar

  11 juillet 2017, par BigRetroMike

  I’m trying to achieve a simple home-based solution for streaming/transcoding video to low-end machine that is unable to play file properly.

  I’m trying to do it with ffmpeg (as ffserver will be discontinued)
  I found out that ffmpeg have build in http server that can be used for this.

  The application Im’ testing with (for seekbar) is vlc

  I’m probably doing something wrong here (or trying to do something that other does with other applications)

  My ffmpeg code I use is :

  d :\ffmpeg\bin\ffmpeg.exe -r 24 -i "D :\test.mkv" -threads 2 -vf
  scale=1280:720 -c:v libx264 -preset medium -crf 20 -maxrate 1000k
  -bufsize 2000k -c:a ac3 -seekable 1 -movflags faststart -listen 1 -f mpegts http://127.0.0.1:8080/test.mpegts

  This code also give me ability to start watching it when I want (as opposite to using rtmp via udp that would start video as soon as it transcode it)

  I readed about moving atoom thing at file begging which should be handled by movflags faststart

  I also checked the -re option without any luck, -r 25 is just to suppress the Past duration 0.xx too large warning which I read is normal thing.
  test file is one from many ones with different encoder setting etc.

  The setting above give me a seekbar but it doesn’t work and no overall duration (and no progress bar), when I switch from mpegts to matroska/mkv I see duration of video (and progress) but no seekbar.

  If its possible with only ffmpeg I would prefer to stick to it as standalone solution without extra rtmp/others servers.

• Strange results when converting rgb yuv using ffmpeg in python

  20 avril 2020, par user3569998

  I have JPG images and I am trying to do the following :

  



  

  1. resize the input and save the result into PNG

  


  2. convert PNG images to YUV (for instance yuv444p10le) in AVI container

  


  3. convert AVI back to PNG image.

  


  



  I am using python 3 and ffmpeg Linux version installed on Colab

  



  I printed the difference between resized_png and restored_png. I have values of 255 which doesn't make sense at all.

  



   [[[  0 255   1]
  [  0   0   1]
  [  0 255   1]
  ...
  [  1   0   0]
  [  1   0   0]
  [  2   0   1]]

 [[  0 255   1]
  [  0 255   1]
  [  1   0   0]
  ...
  [  1   0   0]
  [  1   0   0]
  [  1   0   0]]

 [[  0   0   1]
  [  0   0   1]
  [  0   0   1]
  ...
  [  1 255   0]
  [  1 255   1]
  [  1   0   0]]

 ...

 [[255   0   0]
  [255   0   1]
  [255   0   1]
  ...
  [  0   0   0]
  [  0   0   1]
  [255   0   1]]

 [[255   0   1]
  [255   0   1]
  [255   0   1]
  ...
  [  0   0   1]
  [  0   0   1]
  [  0   0   0]]

 [[255   0   1]
  [255   0   1]
  [255   0   1]
  ...
  [255   1   0]
  [255   0   0]
  [255   0   1]]]


  



  input_image = '/content/drive/My Drive/Colab Notebooks/adv_dnn/datasets/im2.jpg'
output_resized = '/content/drive/My Drive/Colab Notebooks/adv_dnn/datasets/im2.png'
folder_path = '/content/drive/My Drive/Colab Notebooks/adv_dnn/datasets/'

#do resize
# code = subprocess.call('cd /usr/bin/ffmpeg',  shell=True)
# print(code)
cmd_resize = ['ffmpeg', '-y', '-i',  input_image,'-vf', 'scale=224:224', output_resized]
process = subprocess.Popen(cmd_resize, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = process.communicate()
print(out)
print(err)

fmt = ['yuv420p', 'yuv420p10le', 'yuv444p', 'yuv444p10le']
for f in fmt:
  cmd2YUV = ['ffmpeg', '-y', '-i', output_resized, '-c:v', 'libx264', '-preset', 'placebo',\
             '-qp', '0', '-x264-params', "keyint=15:no-deblock=1", '-pix_fmt', f, \
             '-sws_flags', 'spline+accurate_rnd+full_chroma_int', \
             '-vf', "colorspace=bt709:iall=bt601-6-625:fast=1", '-color_range', '1', '-colorspace', '1', 
             '-color_primaries', '1', '-color_trc', '1', folder_path+'im2_'+f+'.avi']
  process = subprocess.Popen(cmd2YUV, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  out, err = process.communicate()
  print(out)
  print(err)

  cmd2PNG = ['ffmpeg', '-y', '-i',  folder_path+'im2_'+f+'.avi', '-compression_level', '10', '-pred', 'mixed', \
             '-pix_fmt', 'rgb24', '-sws_flags', '+accurate_rnd+full_chroma_int', \
             folder_path+'im2_'+f+'.png']
  process = subprocess.Popen(cmd2PNG, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  out, err = process.communicate()
  print(out)
  print(err)

im1=pilim.open('/content/drive/My Drive/Colab Notebooks/adv_dnn/datasets/im2.png')
im2=pilim.open('/content/drive/My Drive/Colab Notebooks/adv_dnn/datasets/im2_yuv444p10le.png')
im1_2d = np.asarray(im1)
im2_2d = np.asarray(im2)
print(im2_2d-im1_2d)