Oggz 1.1.0 Release
------------------
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 features 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.
This release is available as a source tarball at:
http://downloads.xiph.org/releases/liboggz/liboggz-1.1.0.tar.gz
New in this release
==================
This release introduces a new API structure for reporting the byte
offsets of the start and end pages for each packet.
Details
======
An Ogg packet can span multiple pages. It is often useful to know
which page a packet started and ended on -- in particular, an
application may want to cache the byte offset of the start of
certain packets in order to more easily return to that position
in the file later.
As of liboggz 1.1.0, an OggzRead callback provides an oggz_packet:
/**
* An ogg_packet and its position in the stream.
*/
typedef struct {
/** The ogg_packet structure, defined in <ogg/ogg.h> */
ogg_packet op;
/** Its position */
oggz_position pos;
} oggz_packet;
Older applications will continue to work, casting this structure as
an ogg_packet. The new structure includes additional information in
the pos field, of type oggz_position:
/**
* The position of an oggz_packet.
*/
typedef struct {
/**
* Granulepos calculated by inspection of codec data.
* -1 if unknown
*/
ogg_int64_t calc_granulepos;
/**
* Byte offset of the start of the page on which this
* packet begins.
*/
oggz_off_t begin_page_offset;
/**
* Byte offset of the start of the page on which this
* packet ends.
*/
oggz_off_t end_page_offset;
/** Number of pages this packet spans. */
int pages;
/**
* Index into begin_page's lacing values
* for the segment that begins this packet.
* NB. if begin_page is continued then the first
* of these packets will not be reported by
* ogg_sync_packetout() after a seek.
* -1 if unknown.
*/
int begin_segment_index;
} oggz_position;
Public API
----------
* Added <oggz/oggz_packet.h>: add oggz_packet definition, and
implement reader to return oggz_packet in OggzReadPacket callback.
* Updated shared version info to 8.0.6
Internal
--------
* Improved accuracy of byte position tracking during reading,
as reported by oggz_tell()
About Oggz
=========
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, 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 list of codecs found in one or more files and
their bitstreams.
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.
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,
CMML, CELT 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/
License
-------
Oggz is Free Software, available under a BSD style license.
More information is available online at the Oggz homepage:
http://www.xiph.org/oggz/
enjoy :)
--
Conrad Parker, Annodex Association
http://www.annodex.net/
