Media Validation Service

Overview

This service can be used to validate Web-accessible Ogg, CMML and Annodex resources.

HTTP reporting

The following HTTP actions are reported:

• Any HTTP redirections encountered while attempting to access the resource
• In case of error, the status code of the HTTP response
• The Content-Type HTTP response header as reported by the server
• The value of the X-Accept-TimeURI HTTP header. For more information see the Time intervals in URIs Internet-Draft section 6.1.
• For Annodex resources (URLs returning Content-Type */annodex), an attempt will be made to retrieve and validate the associated CMML by requesting the same URL with the additional HTTP request header Accept: text/x-cmml. For more information, see the Annodex Internet-Draft section 6.1.2.

Ogg media validation

This service recognizes Ogg media resources of the following content types:

• application/ogg
• audio/ogg
• video/ogg
• audio/vorbis
• audio/speex
• video/theora
• application/annodex
• video/annodex
• audio/annodex

• application/x-ogg
• audio/x-ogg
• video/x-ogg
• audio/x-vorbis
• audio/x-speex
• video/x-theora
• application/x-annodex
• video/x-annodex
• audio/x-annodex

The following types of errors can be detected in Ogg framing:

• File contains no Ogg packets
• Packets out of order
• Packet belongs to unknown serialno
• Granulepos decreasing within track
• Multiple bos packets
• Multiple eos packets
• eos marked but no bos
• Missing eos packets
• Granulepos on page with no completed packets
• Theora video bos page after audio bos page

Please note that only the first 1024KB of the media resource are retrieved. Validation of media content is performed by oggz-validate.

CMML Markup validation

This service recognizes CMML resources of content type:

• text/cmml

• text/x-cmml

The following types of errors can be detected in CMML markup:

• Error in formatting of time in a required tag
• General parsing error
• No cmml tag was found
• No head tag was found
• there is a head or a clip tag before the stream
• there is a clip tag before the head tag
• there are two stream tags
• there are two head tags

Additionally, the following warnings will be given for CMML markup:

• error in the formatting of an implied attribute
• skipping an unknown tag
• skipping a faulty tag
• xmlns in cmml tag is wrongly redefined
• clip with start time in the "past" skipped

Validation of CMML content is performed by cmml-validate.

Source code

Source code for this service is available from: