Metadata 1.0

tarball: http://dark.fhtr.org/repos/metadata/metadata-1.0.tar.gz
gem: http://dark.fhtr.org/repos/metadata/metadata-1.0.gem
git: http://dark.fhtr.org/repos/metadata

Thanks

Konrad M. for his patient testing and bug reports.
Darren Kirby for the heads-up on wmainfo’s ASF-parsing capabilities
(along with being the author of wmainfo-rb and flacinfo-rb.)

Description

This package Metadata' comes with a library calledmetadata’ and
a small program called `mdh’.

The library probes files for their metadata (e.g. jpeg dimensions
and camera make, mp3 artist, pdf text and word count) and returns the
metadata as a Hash. All strings in the metadata are converted to
UTF-8.

The `mdh’-program can print out file metadata as YAML and package the
metadata with the file.

The metadata hash follows the shared file metadata spec naming, with
some
additional fields, see list at the end of this file (Appendix A.)

For details on the MDH file format, see the end of this file (Appendix
B.)

Example output

$ mdh break__enter.flac

Audio.Performer: The Prodigy
Audio.Album: Music For The Jilted Generation
Audio.Samplerate: 44100
Audio.TrackNo: 2
Audio.Bitrate: 800.0
Audio.Title: Break & Enter
Audio.Genre: (18)
Audio.Duration: 608.0
Audio.ReleaseDate: 1994-01-01T00:00:00Z
File.Size: 60889216
Audio.Codec: fLaC
Audio.Channels: 2
File.Modified: !timestamp 2007-09-21T10:59:38+0300
File.Format: audio/x-flac
Audio.Artist: The Prodigy

$ mdh random_plastic.mpeg

Video.Duration: 236.0
Audio.Samplerate: 44100
Audio.Bitrate: 64.0
Video.Framerate: 10.0
Image.DimensionUnit: px
Video.Codec: FMP4
File.Size: 4854088
Image.Width: 422
Image.Height: 364
Video.Bitrate: 90.624
Audio.Codec: “80”
Audio.Channels: 2
File.Modified: !timestamp 2007-09-21T10:57:16+0300
Video.Demuxer: avi
File.Format: video/x-msvideo

Usage

print out metadata for myfile.jpg

mdh myfile.jpg

create myfile.jpg.mdh, which consists of an MDH metadata header +

myfile.jpg
mdh -c myfile.jpg

print out the metadata header from an MDH file

mdh -e -p myfile.jpg.mdh

strip out the metadata header from an MDH file and save it to

myfile.jpg
mdh -e myfile.jpg.mdh

print out the list of options

mdh -h

irb> require ‘metadata’
irb> Metadata.extract(‘myfile.jpg’)
irb> Metadata.extract_text(‘myfile.pdf’)
irb> Pathname.new(“myfile.jpg”).metadata

List of supported formats

Audio:
Whatever you manage to make mplayer play.
Plus special handlers for FLAC, m4a, ape, musepack, wavepack and
wma.
Successfully tested with:
mp3, flac, ogg, wav, ra, m4a, wma
Should also work:
wv, mpc, ape

Video:
Whatever you manage to make mplayer play.
Successfully tested with:
wmv, mov, divx, xvid, flv, ogm, mpg, mkv

Images:
Should handle pretty much anything (apart from ORF.)
Successfully tested with:
jpeg, png, gif, nef, dng, crw, pef, psd, tga, tif, xcf, xpm, ppm,
bmp

Documents:
Successfully tested with:
pdf, ppt, odp, sxi, ps, ps.gz, html, txt
Should work:
- OpenOffice docs work to some degree (personally, I’m using unoconv
to
convert OO docs to temp PDFs for the text & dimensions extraction,
so
those bits of data are missing.)
- MS Office docs to some degree (ppt at least, doc and xls should
work too,
dimensions missing due to the above temp PDF -thing.)

Others:
- BitTorrent .torrent files
- Archive contents
- Whatever `extract’ outputs and I am handling

Requirements

  • Ruby 1.8

  • Tons of metadata extraction programs and libs.
    This package has many dependencies since there is no single
    universal
    metadata header format that all files use. Blame resource forks,
    filename
    extensions, bags of bytes and mimetypes.

    List of gems:
    flacinfo-rb
    wmainfo-rb
    MP4Info
    id3lib-ruby
    apetag

    List of Debian packages:
    dcraw
    libimlib2-ruby
    extract
    libimage-exiftool-perl
    poppler-utils
    mplayer
    html2text
    imagemagick
    unhtml
    pstotext
    antiword
    catdoc
    shared-mime-info

  • You do want to install the latest versions of dcraw and
    shared-mime-info to be able to handle camera raw images.
    http://cybercom.net/~dcoffin/dcraw/
    http://freedesktop.org/wiki/Software/shared-mime-info

  • Python + chardet library
    http://chardet.feedparser.org/

Install

De-compress archive and enter its top directory.
Then type:

($ su)
# ruby setup.rb

These simple step installs this program under the default
location of Ruby libraries. You can also install files into
your favorite directory by supplying setup.rb some options.
Try “ruby setup.rb --help”.

Appendix A: Additional metadata fields

This list contains the metadata fields added to the shared
file metadata spec.
http://wiki.freedesktop.org/wiki/Specifications/shared-filemetadata-spec

field name | field type

Archive.Contents array of pathnames

Audio.Band string
Audio.Composer string
Audio.Conductor string
Audio.Copyright string (copyright message)
Audio.Grouping string
Audio.Image binary string (embedded image data)
Audio.InterpretedBy string
Audio.Lyricist string
Audio.Publisher string
Audio.RemixedBy string
Audio.Subtitle string
Audio.Tempo integer
Audio.VariableBitrate boolean
Audio.Writer string
Audio.Publicationright string
Audio.File string
Audio.EAN/UPC string
Audio.ISBN string
Audio.Catalog string
Audio.LC string
Audio.Media string
Audio.Index string
Audio.Related string
Audio.ISRC string
Audio.Abstract string
Audio.Language string
Audio.Bibliography string
Audio.Introplay string
Audio.Dummy string
Audio.DebutAlbum string
Audio.RecordDate string
Audio.RecordLocation string

Doc.Album string
Doc.Artist string
Doc.Charset string
Doc.Description string
Doc.Genre string
Doc.Language string
Doc.ModifyDate date
Doc.PageSizeName string (A4, A5, letter, …)

File.Software string (software used to create the file)

Image.DateCreated date
Image.DateTimeCreated date
Image.DateTimeOriginal date
Image.DimensionUnit string (px, mm, pt, …)
Image.EXIF string (exiftool output)
Image.Frames integer
Image.Modified date
Image.OriginatingProgram string

Location.Latitude float
Location.Longitude float

Video.Album string
Video.Artist string
Video.Bitrate integer
Video.Codec string
Video.Comment string
Video.Duration float
Video.Framerate float (frames per second)
Video.Genre string
Video.ReleaseDate date
Video.Title string
Video.TrackNo integer
Video.Demuxer string

BitTorrent.Name string
BitTorrent.Files array of { ‘path’ => string,
‘length’ => integer,
‘md5sum’ => string }
BitTorrent.Length integer (size of single-file torrents)
BitTorrent.MD5Sum string (md5sum for single-file torrents)
BitTorrent.PieceCount integer
BitTorrent.PieceLength integer (length of a single piece
BitTorrent.Comment string
BitTorrent.Announce string (announce url)
BitTorrent.AnnounceList array of arrays of strings
BitTorrent.Nodes array of [hostname, port] -arrays

Appendix B: The MDH file format

MDH files are built as follows:

bytes | content

3   | "MDH"  - MDH file format identifier
1   | "\x01" - MDH file format version number
4   | Long, network byte order - the size of the metadata struct in 

bytes
var | YAML - The MDH metadata struct
var | The actual file contents

All string fields in the metadata are UTF-8.

License

Ruby’s

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