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• Windows server crashs in video transcode during

  6 février 2019, par parsa

  I’m using ffmpeg for transcoding of my videos on a HP Blade dedicated server with these details :

  OS : Windows Server 2012 R2 64Bit
  CPU : Intel XEON X5650
  RAM : 16GB
  Hard disk : A sas normal disk

  This command is a sample for creating qualities which has 4K as top level and
  I use this command for creating lower qualities from that as parallel at the same time.

  ffmpeg -i input.mp4 -filter_complex 
  
  [0:v]split=4[s0][s1][s2][s3];
  
  [s0]scale=uhd2160[v0];
  
  [s1]scale=hd1080[v1];
  
  [s2]scale=hd720[v2];
  
  [s3]scale=hd480[v3];
  
  [s4]scale=nhd[v4];
  
  [s5]scale=cga[v5]
  
  -map [v0] -map [v1] -map [v2] -map [v3] -map [v4] -map [v5] -map 0:a 
  
  -c:v libx264 -c:a aac -f tee -g 48 -threads 0 
  
  "[select='v\:0,a':f=hls:hls_list_size=0:hls_time=6]../video/2160p/out.m3u8| 
  
   [select='v\:1,a':f=hls:hls_list_size=0:hls_time=6]../video/1080p/out.m3u8| 
  
   [select='v\:2,a':f=hls:hls_list_size=0:hls_time=6]../video/720p/out.m3u8| 
  
   [select='v\:3,a':f=hls:hls_list_size=0]../video/480p/out.m3u8| 
  
   [select='v\:3,a':f=hls:hls_list_size=0:hls_time=6]video/360p/out.m3u8| 
  
   [select='v\:3,a':f=hls:hls_list_size=0:hls_time=6]video/200p/out.m3u8"

  Some times in transcoding time windows goes to reconnecting and count up to 20 and then goes to black screen.
  I cannot find anythings in windows logs.
  And finally I restart server from button of that server.
  What’s hapenning ?
  How can I find a clue, about this issue ?
  Any one know anything about this issue ?

• How can I automatically embed commit information into a subtitles file that I'm tracking ?

  23 février 2015, par microspace

  I use git to track *.ass subtitle files.
  Here is example of *.ass file :

  [Script Info]
  
  ; Script generated by Aegisub 3.1.2
  
  ; http://www.aegisub.org/
  
  Title: Default Aegisub file
  
  ScriptType: v4.00+
  
  
  
  [V4+ Styles]
  
  Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour,    BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
  
  Style: Default,Arial,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,2,2,10,10,10,1
  
  Style: titr,DejaVu     
  
  
  
  Sans,20,&H007DDBFA,&H000000FF,&H00000000,&HFF000000,0,0,0,0,100,100,0,0,1,2,2,1,10,10,10,1
  
  
  
  [Events]
  
  Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
  
  Dialogue: 0,0:00:00.46,0:00:11.22,Default,,0,0,0,,Если это можно было бы
  
  Dialogue: 0,0:00:03.44,0:00:08.96,titr,,0,0,0,,{\pos(20,240)\fad(600,600)}бывший министр

  After commit I burn subtitles into video :

  ffmpeg -i video.avi -vf "ass=subtitle.ass" out.avi

  My goal is to show commit date for 10 second at the start of movie. This should be done automatically.

  1) It can be easily done with by modifying subtitle.ass itself, but I can’t do it after commit and there are other reasons.

  2) It can be done by ffmpeg from command line : How to use ffmpeg to add a text to avi video ?

  Problem is that in this case text will be shown for the whole lenght of movie.

  3) I can copy *.ass file to temporary directory, insert date, render and delete *.ass file.

  Is there a simpler way ?

• Remove Static Pixels from a Video to Mimic a Green Screen Effect [closed]

  2 août 2021, par nKrkan

  I have a video that's 50 seconds in length, resolution of 480x480 and 16 frames per second.

  


  There is a person talking in it, with the background being static I thought if there's a way
  
to remove those static pixels (background) and just extract the moving pixels (foreground)
  
and possibly mimic a green screen effect ?

  


  I was thinking on writing a picture-by-picture comparison tool to do such thing but I don't
  
believe I'm up to the task, or maybe It's laziness.

  


  And now I know, some of you will point out that the video has compression artifacts and that
  
might cause some problems but It doesn't have to be Studio quality stuff.

  


  I tried the ffmpeg command from this question : Remove random background from video using ffmpeg or Python
  
And it does mask the person, but... I couldn't quite get it to work, apparently putting the
  
reference image in the input makes that image burned into the video, thus having no way to
  
remove it, but it did mask the background as black and the person as greenish, so still not a
  
viable way to do it.

  


  Have also tried some Python projects I've found on the GitHub but none of them worked as
  
I expected.

  


  So, what I thought to do is simply compare the first and the second frame of the video, check
  
all the pixels by comparing them with the two sources, and change those that stay within a
  
certain range of the initial pixel value.

  


  I should point out I'm not very knowledgeable with mathematics and the majority of the
  
methods used in these type of things, but perhaps someone could point me to an interesting
  
source to read and learn, or by providing an alternative to the methods aforementioned above.