Raw

This document [ draft-walsh-mmusic-img-envelope-03] defines the metadata transfer envelope for Internet Media Guides (IMGs). IMG metadata describes files, resources and multimedia programs available for streaming or downloading via multicast or unicast.

Complete with XML format. I've only skimmed, but it appears to be a wrapper for pointing to the actual metadata for the media itself.

Once again, my personal response is bemusement at yet-another metadata/resource description format that ignores RDF. If I understand correctly this particular bit is only intended to make the actual metadata discoverable. But still, surely it could be done a little more systematically than this:

<?xml version="1.0" encoding="UTF-8"?>
<metadataEnvelope
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:noNamespaceSchemaLocation="envelope.xsd"
  metadataURI="http/www.example.com/img001/session001.sdp"
  version="1"
  validFrom="2003-12-17T09:30:47-05:00"
  validUntil="2003-12-17T09:30:47-05:00"
  contentType="application/sdp">
  <metadataFragment>
    v=0
    o=mhandley 2890844526 2890842807 IN IP4 126.16.64.4
    s=SDP Seminar
    i=A Seminar on the session description protocol
    u=http://www.cs.ucl.ac.uk/staff/M.Handley/sdp.03.ps
    e=mjh@isi.edu (Mark Handley)
    c=IN IP4 224.2.17.12/127
    t=2873397496 2873404696
    a=recvonly
    m=audio 49170 RTP/AVP 0
    m=video 51372 RTP/AVP 31
    m=application 32416 udp wb
    a=orient:portrait
  </metadataFragment>
</metadataEnvelope>

I've no idea of how strongly supported in the media-delivery industry IMG is. But on the scruffy public Web at least I've a feeling this stuff is likely to be blown out of the water by semi-ad hoc XML efforts like Yahoo's Media RSS.

If anyone wishes to integrate data from all these different formats, there's a framework I'd recommend…

[Danny]