+++ /dev/null
-
-
-ABOUT LIBA52
-
-liba52 is a free library for decoding ATSC A/52 streams. It is
-released under the terms of the GPL license. The A/52 standard is used
-in a variety of applications, including digital television and DVD. It
-is also known as AC-3.
-
-The main goals in liba52 development are:
-
- * Portability - Currently all of the code is written in C, and
- when we write platform-specific optimizations we will always
- keep a generic C routine to fall back on.
-
- * Reuseability - we do not want liba52 to include any
- project-specific code, but it should still include enough
- features to be used by very diverse projects.
-
- * Precision - We are trying to implement all of the A/52
- standard, and to have a very precise output by doing all the
- calculations in floating point. We have a test suite that
- detects any deviation in the output when compared to previous
- versions. We do not have access to official A/52 test vectors
- though, so we have to use our judgement to ensure that such
- deviations are only intruduced when we fix bugs !
-
- * Speed - liba52 is really fast, on any modern PC it should take
- only a few percent of CPU time.
-
-The project homepage is at http://liba52.sourceforge.net/
-
-
-A52DEC
-
-a52dec is a test program for liba52. It decodes ATSC A/52 streams, and
-also includes a demultiplexer for mpeg-1 and mpeg-2 program streams.
-
-The liba52 source code is always distributed in the a52dec package, to
-make sure it easier for people to test it.
-
-The basic usage is to just type "a52dec file" where file is an ATSC
-A/52 file.
-
-The "-s" option must be used for multiplexed (audio and video) mpeg-2
-files. These files are usualy found on the internet or on unencrypted
-DVDs.
-
-The "-o" option is used to select a given output layer. By default
-a52dec does a stereo downmix and outputs to your speakers, but you can
-try other choices using this option. This is also used for performance
-testing and conformance testing.
-
-The "-c" option is used to disable all optimizations (currently only djbfft).
-
-The "-r" option is used to disable the dynamic range compression.
-
-
-OTHER PROJECTS USING LIBA52
-
-liba52 (and its ancestor libac3) is being used by various other
-projects, including:
-
- * xine (http://xine.sourceforge.net/) - started as a simple
- mpeg-2 audio and video decoder, but it since became a
- full-featured DVD and video media player.
-
- * MPlayer (http://www.MPlayerHQ.hu) - another good player, it is
- also very robust against damaged streams.
-
- * movietime (http://movietime.sourceforge.net/) - still quite
- young, but it looks very promising !
-
- * ffmpeg (http://ffmpeg.sourceforge.net/) - a nice audio/video
- encoder and transcoder, uses liba52 for decoding A/52 streams.
-
- * Ogle (http://www.dtek.chalmers.se/groups/dvd/) - a good DVD
- player with menu support
-
- * OMS (http://www.linuxvideo.org/oms/)
-
- * XMPS (http://xmps.sourceforge.net/)
-
- * GStreamer (http://www.gstreamer.net/) - a framework for
- streaming media; it has an A/52 decoding plugin based on liba52.
-
- * mpeglib (http://mpeglib.sourceforge.net/) - a video decoding
- library that usess liba52 when decoding A/52 streams.
-
-If you use liba52 in another project, let us know !
-
-VideoLAN (http://www.videolan.org/) does not use liba52, but this is
-still a cool project :)
-
-
-TASKS
-
-There are several places where we could easily use some help:
-
- * Web design: This site sucks ! at the very least, we'd like to
- come up with a nicer background picture and a logo.
-
- * Testing: If you find any stream that does not decode right
- with liba52, let us know ! The best thing would be to mail to
- the liba52-devel mailing list. Also if you have access to
- encoders, we'd love to get test streams that would be free of
- rights - so that we can put them on this server.
-
- * Coding: you can have a look in the TODO file first ! The most
- important item is probably to make the code fully reentrant.
-
- * Porting: If you're porting to a new architecture, you might
- want to experiment with the compile flags defined in
- configure.in . When you figure out whats fastest on your
- platform, send us a patch !
-
-
-REFERENCES
-
-The A/52 standard is publically available at these locations:
-
- * http://www.atsc.org/standards/a_52a.pdf - The main part of the
- standard, as published by the ATSC.
-
- * http://www.dolby.com/tech/ATSC_err.pdf - A list of erratas in
- the ATSC standard, published by Dolby. It applies to the
- previous revision of the standard (A/52 not A/52a), but some
- erratas have not been fixed in the updated standard yet !
-
-
-CVS SNAPSHOTS
-
-A daily snapshot is created using "make distcheck" every night and
-uploaded to http://liba52.sourceforge.net/files/a52dec-snapshot.tar.gz .
-It is easier to use than the CVS repository, because you do not need
-to have the right versions of automake, autoconf and libtool
-installed. It might be convenient when working on a liba52 port for
-example.
-
-
-CVS REPOSITORY
-
-The latest liba52 and a52dec source code can always be found by
-anonymous CVS:
-
-# export CVSROOT=:pserver:anonymous@cvs.liba52.sourceforge.net:/cvsroot/liba52
-# cvs login (Just press Return when prompted for a password)
-# cvs checkout a52dec
-
-You can also browse the latest changes online at
-http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/liba52/a52dec/
-
-The other CVS modules are ac3dec-livid for the CVS history of the
-project while it was still hosted on the linuxvideo.org servers, and
-ac3dec for the CVS history of the project while the linuxvideo.org
-servers were down and before the library switched its name to liba52.
-
-
-MAILING LISTS
-
-See the subscription information at http://liba52.sourceforge.net/lists.html
-
-liba52-devel
-
-This is the main mailing list for technical discussion about
-liba52. Anyone wanting to work on liba52, or maybe just stay informed
-about the development process, should probably subscribe to this list.
-
-liba52-checkins
-
-All liba52 checkins are announced there. This is a good way to keep
-track of what goes into CVS.
-
-liba52-announce
-
-This is a very low traffic mailing list, only for announcements of new
-versions of liba52. Only project administrators can post there.