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• Mac terminal command to list files and sort by date to use in ffmpeg

  22 septembre 2020, par Jeff

  I am using a gopro to film a bunch of videos. I want to then take those videos directly from the SD card folder and concatenate them into a single video (bypass an editor) by using FFMPEG.

  


  I'm currently able to stitch together "chaptered" videos with the following example command on my Mac (10.13) :

  


  ffmpeg -f concat -safe 0 -i <(for f in /sdcardfolder/100GOPRO/GH*488.MP4; do echo "file '$f'"; done) -c copy /folder/video.mp4

  


  The reason for this is that the ffmpeg command requires a text file that looks like this :

  


  


  file '/folder/GH016992.MP4'

  
file '/folder/GH036990.MP4'

  
...

  


  


  The real command is this, which generates the list of files in the right format with file in front of each one and can be embedded into the ffmpeg command :

  


  for f in /Volumes/GoPro8/DCIM/100GOPRO/GH0*71*.MP4; do echo "file '$f'"; done

  


  I want to add 2 changes to this :

  


  


  1. List the files in date order (ascending) : I want the list of files to be in date order. But I can't figure out how to add a -sort or something to the for f in command.

     


  


  2. Allow a more robust set of file matching/filtering : Right now I can add basic regex like GH*488.MP4 or, with chapters which increments the first number, something like GH0[123]488.MP4 would work to just get the first few. But when I change it to be more flexible like GH0[0-9]71[0-9][0-9].MP4 - which would be necessary to match all files that were recorded yesterday, but nothing before then, the command doesn't like this regex. It seems to only accept a *.

     


  


  


  I looked at a few examples like https://opensource.com/article/19/6/how-write-loop-bash but there wasn't much more than just listing files.

  


  This boils down to a terminal command and isn't really related to FFMPEG but I hope it's helpful context.

  


  I imagined it would be something like this, but this definitely doesn't work :

  


  for f in (find /Volumes/GoPro8/DCIM/100GOPRO/GH0[0-9]71[0-9][0-9].MP4 -type f | sort); do echo "file '$f'"; done

  


  I'd appreciate any help ! Thanks !

  


  Update

  


  It looks like sorting isn't easy with Mac tools so I gave up and wrote a much simpler Ruby script that could execute everything for me. This is not really an answer to my question above but it is a solution.

  


  Here I can easily write the text file necessary for ffmpeg and I can also filter files with a regex on the name, filter for a particular date, and size. Then, via the script, simply execute the ffmpeg command with args to concat files. I can also have it immediately resample the file to compress it (gopro videos are giant and I'm ok with a much lower bitrate if I want to save raw footage).

  


  I got lucky with this Dir.entries in Ruby - it seems to automatically sort by date ? I don't know how to sort it otherwise.

  


  PATH = '/Volumes/GoPro8/DCIM/100GOPRO/'
NEW_FILENAME = '/folder/new-file.mp4'
video_list = '/folder/ffmpeg-list.txt'

# create the text file
File.delete(video_list) if File.exist?(video_list)
i = 1
Dir.entries(PATH).each do |f|
    d = File.mtime(PATH + f)
    size = File.size(PATH + f)
    if f.match(/GH0.*.MP4/) && d.to_s.match(/2020-07-30/) && size.to_i < 1000000000
        puts "#{i}\t#{f}\t#{d}\t#{size}"
        File.write(video_list, "file #{PATH + f}\n", mode: "a")
        i= i+1
    end
end

command = "ffmpeg -f concat -safe 0 -i #{video_list} -c copy #{NEW_FILENAME}"

puts "executing concatenate..."
puts command
system(command)


  


• FFMpeg concatenation with large list of inputs — how to minimize command line length

  27 août 2020, par huitlacoche

  I have a python tool that concatentates several mp4s together into a single movie file using FFMPEG run from a subprocess call. The issue is that an arbitrarily large number of inputs in the command string will hit the windows CLI character max.

  


  ffmpeg -y -i a.mp4 -i b.mp4 -i c.mp4 -f lavfi -t 0.1 -i anullsrc  -filter_complex '[0]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2: (oh- ih)/2,setsar=1[0:v];[1]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(owiw)/2:(oh-ih)/2,setsar=1[1:v];[2]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow- iw)/2:(oh-ih)/2,setsar=1[2:v]; [0:v][3:a][1:v][3:a][2:v][3:a]concat=n=3:v=1:a=1[v][a]' -c:v libx264 -map [v] -map [a] output.mp4

  


  Assuming 3 input movies that may or may have audio (hence the null audio source).
This works fine assuming there are no more than 30-50 input files. Often the input files have rather long filepaths and can get long very quickly.

  


  After doing a bit of reading I tried a simple :

  


  ffmpeg -f concat -i files.txt -c copy output.mp4

  


  Which works if I can guarantee that all the files are the same codec/resolution/etc, but this cannot be guaranteed.
I'm not clear on how to translate my filter_complex to work with a text file of inputs. Finding a specific enough solution has proven elusive.

  


  I'd be perfectly fine assigning the input paths to a temporary environment variable but in my use case this doesn't seem to work either. The subprocess call doesn't seem to translate wildcard %MYVAR% calls to environment variables.

  


  I feel like there has to be an answer to this problem. If anyone can suggest a solution I would greatly appreciate it.

  


  Thanks !

  


• Can't list input devices ffmpeg linux

  23 juillet 2021, par spindi598

  On windows I could do something like this to list input devices :

  


  ffmpeg -list_devices true -f dshow -i dummy


  


  On Linux I try doing something like this :

  


  ffmpeg -list_devices true -f <x11grab></x11grab>avfoundation>&#xA;

  


  And I get an error (I have also tried the latest git build from here) :

  


  ffmpeg version n4.2.4 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 10.1.0 (GCC)
  configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-avisynth --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-nvdec --enable-nvenc --enable-omx --enable-shared --enable-version3
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Unrecognized option 'list_devices'.
Error splitting the argument list: Option not found


  


  How can I list my input devices ?