[Theora-dev] mod_annodex 0.2.1 Release

[Conrad Parker]

mod_annodex 0.2.1 Release
=========================

mod_annodex is a module for Apache httpd, and provides server-side support
for annodex media. Parallel versions are available for Apache versions
1.3 and 2.0.

Annodex is an open standards based technology that extends the World Wide
Web's hyperlinking, searching, and compositing infrastructure to
time-continuous data, enabling video surfing, searching for clips of audio
and video files using ordinary Web search engines, and on-the-fly
composition of a video on a Web server from previously annodexed clips.
For more information on Annodex, see http://www.annodex.net/

This release is available at:

	http://www.annodex.net/software/mod_annodex/

New in this release:

	* Support for time ranges of the form "t=start/end", such as

        http://media.example.com/index.anx?t=npt:00:00:10/00:00:20

It is recommended that you upgrade libannodex to version 0.6.1 in order
to make use of this feature. Additionally, libannodex-0.6.1 has undergone
an extensive audit of memory use resulting in the removal of all known
leaks in the codepaths used by mod_annodex.

About mod_annodex
-----------------

mod_annodex is a handler for type application/x-annodex. It provides the
following functionality:

* Time URI handling

Time URIs (see http://www.annodex.net/uri/) are a way of addressing time
points in a resource. mod_annodex implements server-side timed query offsets,
such as

http://media.example.com/fish.anx?t=npt:00:01:20.8

A client retrieving such a resource will view the media stream immediately
from the requested time offset, allowing other annodex media files or web
pages to use such timed hyperlinks to link directly to a point of interest.

http://media.example.com/fish.anx?t=npt:00:01:20.8/00:02:30.4

A client retrieving such a resource will view the media stream immediately from 00:01:20.8, and ending at 00:02:30.4.

* CMML pre-processing

CMML is an HTML-like markup for media, providing timed hyperlinks, metadata
and annotations. Rather than storing fully encoded annodex media, mod_annodex
allows you to store the CMML and the source media file(s) separately. This
allows for easier editing of the annotations, as the CMML is plain XML.
mod_annodex then dynamically generates annodex media upon request of an
annodex resource.

* CMML extraction

If the Accept: HTTP Request header prefers type text/x-cmml over
application/x-annodex, then CMML content is returned. This content is
produced either dynamically by extracting it from stored annodex media, or by
serving a stored CMML file. This behaviour is invoked when a client includes
an Accept HTTP Request header such as any of the following:

Accept: text/x-cmml
Accept: text/x-cmml;q=1.0, application/x-annodex;q=0.5

However, annodex media is served if a client includes an HTTP Request header
such as any of the following:

Accept: */*
Accept: application/x-annodex
Accept: text/x-cmml;q=0.5, application/x-annodex;q=1.0
Accept: text/x-cmml;q=0.0, application/x-annodex;q=1.0

* Annodex version 3 support

Annodex version 3 allows efficient streaming of multimedia content from
arbitrary time offsets. It does this by providing clues in Ogg Skeleton
headers to allow recomposition from keyframe offsets. This ensures that
information required for correct rendering is possible, such as the prior
Ogg Theora video keyframe and the current CMML clip.

Through libannodex, mod_annodex also provides read-only support for reading
and importing Annodex v2 content to allow existing content to be recomposed
in v3 format without modification.

License
-------

mod_annodex is Free Software, available under the Apache Software License
version 1.1.

More information is available online at the mod_annodex homepage:

    http://www.annodex.net/software/mod_annodex/

enjoy :)

--
Conrad Parker
Senior Software Engineer, Continuous Media Web, CSIRO Australia
http://www.annodex.net/   http://www.ict.csiro.au/cmweb/