Documentation files for Oggz

----------------------------

    PATCHES: Instructions for generating patches

    README: this file

    README.symbian: Instructions for building for Symbian

    README.win32: Instructions for building on Win32

Run:

----

    $ oggz help

for documentation of the various oggz commands.

About Oggz

==========

Oggz comprises liboggz and the tool oggz, which provides commands to

inspect, edit and validate Ogg files. The oggz-chop tool can also be

used to serve time ranges of Ogg media over HTTP by any web server that

supports CGI.

liboggz is a C library for reading and writing Ogg files and streams.

It offers various improvements over the reference libogg, including

support for seeking, validation and timestamp interpretation. Ogg is

an interleaving data container developed by Monty at Xiph.Org,

originally to support the Ogg Vorbis audio format but now used for

many free codecs including Dirac, FLAC, Speex and Theora.

Dependencies

------------

Oggz depends only on libogg, available in most free software

distributions, or in source form at: http://xiph.org/downloads/

Support is built-in for parsing the headers of and seeking to time

positions in Ogg Dirac, FLAC, Speex, Theora and Vorbis. Oggz is also

compatible with Annodex streams, and supports seeking on all tracks

described in an Ogg Skeleton track.

Installation

------------

Release archives can be installed using the conventional commands:

    $ ./configure

    $ make check

    $ sudo make install

sequence. Configuration details are in the file INSTALL. If you obtained

this source by svn, first run "./autogen.sh" to create the configure script,

then run the above commands.

Read the file README.win32 for installing under MS Windows, and

README.symbian for information about building for Symbian devices.

Source layout

-------------

    doc/

    doc/liboggz        autocreated by the doxygen tool from comments

                       contained in the public C header files

    include/           public C header files

    src/

    src/liboggz/       library source code.

    src/tools/         command line tools

    src/examples/      example programs using liboggz

    src/tests/         unit and functional tests

    symbian/           files necessary to compile the library for Symbian

    win32/             files necessary to compile the library and tools for

                       Microsoft Windows

Developers

----------

liboggz is maintained in git at git://git.xiph.org/liboggz.git

A list of outstanding tasks is maintained in the TODO file of this source

distribution. When implementing anything listed in this file, please update

it by deleting that entry, and include that as part of the patch or commit

that implements the fix.

Please send patches to ogg-dev@xiph.org

Programming with liboggz

------------------------

liboggz supports the flexibility afforded by the Ogg file format while

presenting the following API niceties:

    * Full API documentation

    * Comprehensive test suite of read, write and seeking behavior.

    The entire test suite can be run under valgrind if available.

    * Developed and tested on GNU/Linux, Darwin/MacOSX, Win32 and

    Symbian OS. May work on other Unix-like systems via GNU autoconf.

    For Win32: nmake Makefiles, Visual Studio .NET 2003, 2005 and 2008

    solution files are provided in the source distribution.

    * Strict adherence to the formatting requirements of Ogg bitstreams,

    to ensure that only valid bitstreams are generated; writes can fail

    if you try to write illegally structured packets.

    * A simple, callback based open/read/close or open/write/close

    interface to raw Ogg files.

    * Writing automatically interleaves with packet queuing, and provides

    callback based notification when this queue is empty

    * A customisable seeking abstraction for seeking on multitrack Ogg

    data. Seeking works easily and reliably on multitrack and multi-codec

    streams, and can transparently parse Theora, Speex, Vorbis, FLAC,

    PCM, CMML and Ogg Skeleton headers  without requiring linking to those

    libraries. This allows efficient use on servers and other devices

    that need to parse and seek within Ogg files, but do not need to do

    a full media decode.

Full documentation of the liboggz API, customization and installation,

and mux and demux examples can be read online at:

    http://www.xiph.org/oggz/doc/

oggz tool

---------

Usage: oggz <subcommand> [options] filename ...

oggz is a commandline tool for manipulating Ogg files. It supports

multiplexed files conformant with RFC3533. Oggz can parse headers for CELT,

CMML, Dirac, FLAC, Kate, PCM, Speex, Theora and Vorbis, and can read and write

Ogg Skeleton logical bitstreams.

Commands:

  help          Display help for a specific subcommand (eg. "oggz help chop")

Reporting:

  codecs        Display the codecs present in an Ogg file

  diff          Hexdump the packets of two Ogg files and output differences.

  dump          Hexdump packets of an Ogg file, or revert an Ogg file from

                such a hexdump.

  info          Display information about one or more Ogg files and their

                bitstreams.

  scan          Scan an Ogg file and output characteristic landmarks.

  validate      Validate the Ogg framing of one or more files.

Extraction:

  rip           Extract one or more logical bitstreams from an Ogg file.

Editing:

  chop          Extract the part of an Ogg file between given start and/or

                end times.

  comment       List or edit comments in an Ogg file.

  merge         Merge Ogg files together, interleaving pages in order of

                presentation time.

  sort          Sort the pages of an Ogg file in order of presentation time.

Miscellaneous:

  known-codecs  List codecs known by this version of oggz

The script bash-completion/oggz enables completion of tool options and codec

names when using the bash shell. Source it from your .profile, or install it

in /etc/bash_completion.d to enable it system-wide.

oggz-chop: General usage and CGI installation

---------------------------------------------

oggz-chop extracts the part of an Ogg file between given start and/or end

times. The output file contains copies of the headers of the input file, and

all the codec data required to correctly decode the content between the start

and end times specified on the commandline. For codecs with data dependencies

like video keyframes, the keyframe prior to the starting time will be included

in the output.

An Apache server can be configured to use oggz-chop to handle all Ogg files

(or, all Ogg files in a particular directory). An example Apache configuration

is in the liboggz source tree, along with a script for installing it on a

Debian server.

The oggz-chop binary checks if it is being run as a CGI script (by checking

some environment variables), and if so acts based on the CGI query parameter

t=, much like mod_annodex. It accepts all the time specifications that

mod_annodex accepts (npt and various smpte framerates), and start and end

times separated by a /.

License

-------

Oggz is Free Software, available under a BSD style license.

More information is available online at the Oggz homepage:

    http://xiph.org/oggz/

enjoy :)

--

Conrad Parker

http://www.annodex.net/