Re: [Tracker] Can a tracker extractor change the MIME type of a input file?

[Martyn Russell <martyn lanedo com>]

On 08/12/10 14:07, Lin, Mengdong wrote:
> > In theory, it is possible, but I don't recommend it.
>
> > Tracker also already would register this file as an "audio" class
> > in the ontology used and written to the database, so the mime type
> > shouldn't need changing if you mean to search for all audio files
> > in Tracker.
>
> How can the tracker recognize the DRM-protected content is a
> "audio"? Do you mean it's the extractor that write the embedded
> media's mime type to the database?

No.

Consider an MP3 and the data we keep about it:

martyn petunia:~$ tracker-info 
file:///home/martyn/Downloads/Bl%C3%A4kki%20-%20Whait%20-%201%20-%2001%20%20Whait.mp3 
| grep -i type
  'rdf:type' = 'http://www.w3.org/2000/01/rdf-schema#Resource'
  'rdf:type' = 
'http://www.semanticdesktop.org/ontologies/2007/01/19/nie#DataObject'
  'rdf:type' = 
'http://www.semanticdesktop.org/ontologies/2007/01/19/nie#InformationElement'
  'rdf:type' = 
'http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#FileDataObject'
  'rdf:type' = 
'http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Media'
  'rdf:type' = 
'http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Audio'
  'rdf:type' = 'http://www.tracker-project.org/temp/nmm#MusicPiece'
  'nie:mimeType' = 'audio/mpeg'

--

You can see that we store it as an nfo:Audio, nfo:Media even an 
nfo:FileDataObject. So you can find all items in Tracker based on any of 
these levels of accuracy. If you want to use the mimeType, it is there 
too of course.

--
Regards,
Martyn