Metadata 1.1

tarball: http://dark.fhtr.org/repos/metadata/metadata-1.1.tar.gz
gem: http://dark.fhtr.org/repos/metadata/metadata-1.1.gem
git: http://dark.fhtr.org/repos/metadata

Changes

  • more README documentation

    • all output fields in appendix
    • grouped tested formats
  • more extensive testing

  • fixed a bug with document text extraction

  • took out empty Document.PageSizeNames

  • use more fields from extract
    (keywords, language, revision history among others)

  • use more dcraw metadata, ignore failed exif for raws

  • renamed Image.Frames to Image.FrameCount

  • added Image.LayerCount for layered images

  • use more fields from exif: colorspace, colormode

  • fixed exif output to use numbers instead of strings where
    appropriate (focal length, exposure time, ISO speed, Fnumber)

  • optional md5sum and/or sha1sum in the metadata:
    mdh [-m] [-s]
    and
    Metadata.sha1sum|md5sum = true|false

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 called metadata’ 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.)

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.
I.e. anything handled by ExifTool, ImageMagick, Imlib2 or dcraw.

Successfully tested with:
  Web formats:
    jpeg, png, gif, svg
  Camera raws:
    nef, dng, crw, pef, orf
  Image editor state dumps:
    psd, xcf
  The rest:
    tga, tif, bmp, xpm, ppm

Documents:
Successfully tested with:
Web formats:
html, txt
Print formats:
pdf, ps, ps.gz
OO formats:
sxi, odp
MS formats:
doc, ppt, xls

- I'm using unoconv to convert OO & MS docs to temp PDFs for the 

text &
dimensions extraction, so those bits of data are missing. MSOffice
docs
are missing dimensions for the same reason. Here’s a way to get
them:
( first, get Thumbnailer: http://dark.fhtr.org/repos/thumbnailer/
)
$ thumbnailer -s 1 -k foo.odp /tmp/foo.jpg
$ mdh foo.odp
$ rm foo.odp-temp.pdf /tmp/foo.jpg

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/
    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: Metadata fields

This list contains the metadata fields output by Metadata and mdh.
The list follows the shared file metadata spec for the most part.
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
v-- ORIGINAL FIELDS USED --v
Audio.Title string
Audio.Artist string
Audio.Album string
Audio.AlbumArtist string
Audio.AlbumTrackCount integer
Audio.TrackNo integer
Audio.DiscNo integer
Audio.Performer string
Audio.Duration float
Audio.ReleaseDate datetime
Audio.Comment string
Audio.Genre string
Audio.Codec string
Audio.Samplerate integer
Audio.Bitrate float
Audio.Channels integer
Audio.Lyrics 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, …)
Doc.RevisionHistory array of strings
Doc.ParagraphCount integer
Doc.LineCount integer
Doc.CharacterCount integer
Doc.LastSavedBy string
Doc.Keywords array of strings
Doc.Template string
v-- ORIGINAL FIELDS USED --v
Doc.Title string
Doc.Subject string
Doc.Author string
Doc.PageCount integer
Doc.WordCount integer
Doc.Created datetime

File.Software string (software used to create the file)
File.MD5Sum string (md5sum of file’s contents)
File.SHA1Sum string (sha1sum of file’s contents)
v-- ORIGINAL FIELDS USED --v
File.Format string (mime type, inode/directory for dirs)
File.Size integer
File.Content string
File.Modified string

Image.DateCreated date
Image.DateTimeCreated date
Image.DateTimeOriginal date
Image.DimensionUnit string (px, mm, pt, …)
Image.Editor string
Image.EXIF string (exiftool output)
Image.FrameCount integer
Image.LayerCount integer
Image.Modified date
Image.OriginatingProgram string
Image.ComponentCount integer
Image.ColorMode string (e.g. RGB)
Image.ColorSpace string (e.g. sRGB)
v-- ORIGINAL FIELDS USED --v
Image.Height float
Image.Width float
Image.Title string
Image.Date datetime
Image.Creator string
Image.Description string
Image.Software string
Image.CameraMake string
Image.CameraModel string
Image.ExposureProgram string
Image.ExposureTime float
Image.Fnumber float
Image.Flash boolean
Image.FocalLength float
Image.ISOSpeed float
Image.MeteringMode string
Image.WhiteBalance string
Image.Copyright 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

On 9/25/07, Konrad M. [email protected] wrote:

Quoth Ilmari H.:

gem: http://dark.fhtr.org/repos/metadata/metadata-1.1.gem

Is the gem working now? If so, very cool.

It’s working, but it’s not on rubyforge. And I’m sort of queasy on
putting it there, due to the dephell of external programs.

Justification for dephell: those projects live or die based on
whether they handle everything in their specialty area. And I’m
too busy for NIH :-/