Class: Aspera::Preview::Utils

Inherits:
Object
  • Object
show all
Defined in:
lib/aspera/preview/utils.rb

Constant Summary collapse

TMPFMT = 
'img%04d.jpg'

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.check_tools(skip_types = []) ⇒ Object

check that external tools can be executed



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# File 'lib/aspera/preview/utils.rb', line 24

def self.check_tools(skip_types=[])
  EXPERNAL_TOOLS.delete(:unoconv) if skip_types.include?(:office)
  # Check for binaries
  EXPERNAL_TOOLS.map{|i|i.to_s}.each do |bin|
    `#{bin} -h 2>&1`
    raise "Error: #{bin} is not in the PATH" if $?.exitstatus.eql?(BASH_EXIT_NOT_FOUND)
  end
end

.external_command(command_symb, command_args, stdout_return = nil) ⇒ Object

execute external command one could use “system”, but we would need to redirect stdout/err

Returns:

  • true if su



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# File 'lib/aspera/preview/utils.rb', line 36

def self.external_command(command_symb,command_args,stdout_return=nil)
  raise "unexpected command #{command_symb}" unless EXPERNAL_TOOLS.include?(command_symb)
  # build command line, and quote special characters
  command=command_args.clone.unshift(command_symb).map{|i| shell_quote(i.to_s)}.join(' ')
  Log.log.debug("cmd=#{command}".blue)
  # capture3: only in ruby2+
  if Open3.respond_to?('capture3') then
    stdout, stderr, exit_status = Open3.capture3(command)
  else
    stderr='<merged with stdout>'
    stdout=%x[#{command} 2>&1]
    exit_status=$?
  end
  if BASH_EXIT_NOT_FOUND.eql?(exit_status)
    raise "Error: #{bin} is not in the PATH"
  end
  unless exit_status.success?
    Log.log.error("commandline: #{command}")
    Log.log.error("Error code: #{exit_status}")
    Log.log.error("stdout: #{stdout}")
    Log.log.error("stderr: #{stderr}")
    raise "command returned error"
  end
  stdout_return.replace(stdout) unless stdout_return.nil?
  return exit_status.success?
end

.ffmpeg(a) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 63

def self.ffmpeg(a)
  raise "error: hash expected" unless a.is_a?(Hash)
  #input_file,input_args,output_file,output_args
  a[:gl_p]||=[
    '-y', # overwrite output without asking
    '-loglevel','error', # show only errors and up]
  ]
  a[:in_p]||=[]
  a[:out_p]||=[]
  raise "wrong params (#{a.keys.sort})" unless [:gl_p, :in_f, :in_p, :out_f, :out_p].eql?(a.keys.sort)
  external_command(:ffmpeg,[a[:gl_p],a[:in_p],'-i',a[:in_f],a[:out_p],a[:out_f]].flatten)
end

.ffmpeg_fmt(temp_folder) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 88

def self.ffmpeg_fmt(temp_folder)
  return File.join(temp_folder,TMPFMT)
end

.get_tmp_num_filepath(temp_folder, file_number) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 92

def self.get_tmp_num_filepath(temp_folder, file_number)
  return File.join(temp_folder,sprintf(TMPFMT,file_number))
end

.shell_quote(argument) ⇒ Object

returns string with single quotes suitable for bash if there is any bash metacharacter



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# File 'lib/aspera/preview/utils.rb', line 18

def self.shell_quote(argument)
  return argument unless argument.split('').any?{|c|BASH_SPECIAL_CHARACTERS.include?(c)}
  return "'"+argument.gsub(/'/){|s| "'\"'\"'"}+"'"
end

.video_blend_frames(temp_folder, index1, index2) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 103

def self.video_blend_frames(temp_folder, index1, index2)
  img1=get_tmp_num_filepath(temp_folder,index1)
  img2=get_tmp_num_filepath(temp_folder,index2)
  count=index2-index1-1
  1.upto(count) do |i|
    percent = 100 * i / (count + 1)
    filename = get_tmp_num_filepath(temp_folder, index1 + i)
    external_command(:composite,['-blend',percent,img2,img1,filename])
  end
end

.video_dump_frame(input_file, offset_seconds, scale, output_file, index = nil) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 114

def self.video_dump_frame(input_file, offset_seconds, scale, output_file, index=nil)
  output_file=get_tmp_num_filepath(output_file,index) unless index.nil?
  ffmpeg(
  in_f: input_file,
  in_p: ['-ss',offset_seconds],
  out_f: output_file,
  out_p: ['-frames:v',1,'-filter:v',"scale=#{scale}"])
  return output_file
end

.video_dupe_frame(temp_folder, index, count) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 96

def self.video_dupe_frame(temp_folder, index, count)
  input_file=get_tmp_num_filepath(temp_folder,index)
  1.upto(count) do |i|
    FileUtils.ln_s(input_file,get_tmp_num_filepath(temp_folder,index+i))
  end
end

.video_get_duration(input_file) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 76

def self.video_get_duration(input_file)
  result = String.new
  external_command(:ffprobe,[
    '-loglevel','error',
    '-show_entries','format=duration',
    '-print_format','default=noprint_wrappers=1:nokey=1',
    input_file],result)
  result.to_f
end

Instance Method Details

#message_to_png(message) ⇒ Object 



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# File 'lib/aspera/preview/utils.rb', line 124

def message_to_png(message)
  # convert -size 400x  -background '#666666' -fill '#ffffff'  -interword-spacing 10 -kerning 4 -pointsize 10 -gravity West -size x22 label:"Lorem dolor sit amet" -flatten xxx.png
  external_command(:convert,[
  ])
end