Class: Mediainfo

Inherits:
Object
  • Object
show all
Extended by:
Forwardable, AttrReaders
Defined in:
lib/mediainfo.rb,
lib/mediainfo/attr_readers.rb

Overview

# Mediainfo

Mediainfo is a class wrapping [the mediainfo CLI](mediainfo.sourceforge.net).

## Installation

$ gem install mediainfo -s http://gemcutter.org

## Usage

info = Mediainfo.new "/path/to/file"

That will issue the system call to ‘mediainfo` and parse the output. You can specify an alternate path if necessary:

Mediainfo.path = "/opt/local/bin/mediainfo"

By default, REXML is used as the XML parser. If you’d like, you can configure Mediainfo to use Hpricot or Nokogiri instead using one of the following approaches:

* define the `MEDIAINFO_XML_PARSER` environment variable to be the 
  name of the parser as you'd pass to a :gem or :require call. 

  e.g. `export MEDIAINFO_XML_PARSER=nokogiri`

* assign to Mediainfo.xml_parser after you've loaded the gem, 
  following the same naming conventions mentioned previously.

  e.g. `Mediainfo.xml_parser = "hpricot"`

Once you’ve got an instance setup, you can call numerous methods to get a variety of information about a file. Some attributes may be present for some files where others are not, but any supported attribute should at least return ‘nil`.

For a list of all possible attributes supported:

Mediainfo.supported_attributes

## Requirements

This requires at least the following version of the Mediainfo CLI:

MediaInfo Command line,
MediaInfoLib - v0.7.25

Previous versions of this gem(<= 0.5.1) worked against v0.7.11, which did not generate XML output, and is no longer supported.

Defined Under Namespace

Modules: AttrReaders Classes: AudioStream, Error, ExecutionError, GeneralStream, ImageStream, IncompatibleVersionError, Stream, StreamProxy, VideoStream

Constant Summary collapse

SECTIONS = 
[:general, :video, :audio, :image]
NON_GENERAL_SECTIONS = 
SECTIONS - [:general]

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from AttrReaders

mediainfo_attr_reader, mediainfo_date_reader, mediainfo_duration_reader, mediainfo_int_reader

Constructor Details

#initialize(full_filename = nil) ⇒ Mediainfo

Returns a new instance of Mediainfo.



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# File 'lib/mediainfo.rb', line 329

def initialize(full_filename = nil)
  if mediainfo_version < "0.7.25"
    raise IncompatibleVersionError,
      "Your version of mediainfo, #{mediainfo_version}, " +
      "is not compatible with this gem. >= 0.7.25 required."
  end
  
  @streams = []
  
  if full_filename
    @full_filename = File.expand_path full_filename
    @path          = File.dirname  @full_filename
    @filename      = File.basename @full_filename
    
    raise ArgumentError, "need a path to a video file, got nil" unless @full_filename
    raise ArgumentError, "need a path to a video file, #{@full_filename} does not exist" unless File.exist? @full_filename
    
    @escaped_full_filename = @full_filename.shell_escape
    
    self.raw_response = mediainfo!
  end
end

Class Attribute Details

.path ⇒ Object

Returns the value of attribute path.



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# File 'lib/mediainfo.rb', line 360

def path
  @path
end

.xml_parser ⇒ Object

Returns the value of attribute xml_parser.



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# File 'lib/mediainfo.rb', line 372

def xml_parser
  @xml_parser
end

Instance Attribute Details

#escaped_full_filename ⇒ Object (readonly)

Returns the value of attribute escaped_full_filename.



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# File 'lib/mediainfo.rb', line 324

def escaped_full_filename
  @escaped_full_filename
end

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/mediainfo.rb', line 324

def filename
  @filename
end

#full_filename ⇒ Object (readonly)

Returns the value of attribute full_filename.



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# File 'lib/mediainfo.rb', line 324

def full_filename
  @full_filename
end

#last_command ⇒ Object (readonly)

Returns the value of attribute last_command.



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# File 'lib/mediainfo.rb', line 391

def last_command
  @last_command
end

#parsed_response ⇒ Object (readonly)

Returns the value of attribute parsed_response.



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# File 'lib/mediainfo.rb', line 324

def parsed_response
  @parsed_response
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/mediainfo.rb', line 324

def path
  @path
end

#raw_response ⇒ Object

Returns the value of attribute raw_response.



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# File 'lib/mediainfo.rb', line 324

def raw_response
  @raw_response
end

#streams ⇒ Object (readonly)

Returns the value of attribute streams.



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# File 'lib/mediainfo.rb', line 84

def streams
  @streams
end

Class Method Details

.default_mediainfo_path! ⇒ Object 



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# File 'lib/mediainfo.rb', line 386

def self.default_mediainfo_path!; self.path = "mediainfo"; end

.delegate(method_name, stream_type = nil) ⇒ Object 



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# File 'lib/mediainfo.rb', line 66

def self.delegate(method_name, stream_type = nil)
  if stream_type == :general
    def_delegator :"@#{stream_type}_stream", method_name
  else
    def_delegator :"@#{stream_type}_stream", method_name, "#{stream_type}_#{method_name}"
  end
end

.load_xml_parser!(parser = xml_parser) ⇒ Object 



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# File 'lib/mediainfo.rb', line 362

def load_xml_parser!(parser = xml_parser)
  begin
    gem     parser
    require parser
  rescue Gem::LoadError => e
    raise Gem::LoadError,
      "your specified XML parser, #{parser.inspect}, could not be loaded: #{e}"
  end
end

.supported_attributes ⇒ Object

AttrReaders depends on this.



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# File 'lib/mediainfo.rb', line 79

def self.supported_attributes; @supported_attributes ||= []; end

.version ⇒ Object 



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# File 'lib/mediainfo.rb', line 74

def self.version
  @version ||= `#{path} --Version`[/v([\d.]+)/, 1]
end

Instance Method Details

#inspect ⇒ Object 



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# File 'lib/mediainfo.rb', line 393

def inspect
  super.sub(/@raw_response=".+?", @/, %{@raw_response="...", @})
end

#mediainfo_version ⇒ Object 



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# File 'lib/mediainfo.rb', line 389

def mediainfo_version; self.class.version; end

#size ⇒ Object

Size of source file as reported by File.size. Returns nil if you haven’t yet fired off the system command.



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# File 'lib/mediainfo.rb', line 88

def size; File.size(@full_filename) if @full_filename; end

#xml_parser ⇒ Object 



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# File 'lib/mediainfo.rb', line 384

def xml_parser; self.class.xml_parser; end