Update README, license and related files for AOM

Author: palemieux

AUTHORS

@@ -1,6 +1 @@
-Jean-Marc Valin (jmvalin@jmvalin.ca)
-Koen Vos (koenvos74@gmail.com)
-Timothy Terriberry (tterribe@xiph.org)
-Karsten Vandborg Sorensen (karsten.vandborg.sorensen@skype.net)
-Soren Skak Jensen (ssjensen@gn.com)
-Gregory Maxwell (greg@xiph.org)
+Please consult the git commit logs for a list of contributors.

CONTRIBUTING.md

@@ -0,0 +1,23 @@
+# How to Contribute
+
+We welcome community contributions to liboac. Thank you for your time!
+
+## Contributor License Agreement
+
+In order to contribute, you must execute the appropriate [Contributor License Agreement](https://aomedia.org/about/legal/#contributor-license-agreements) to ensure that the AOMedia has the right to distribute your changes.
+
+## Contribution process
+
+- Validate that your changes do not break a build
+  - either locally or through travis-ci and github actions. Preferably all of them.
+- Perform smoke tests and ensure they pass
+- Submit a pull request for review to the maintainer
+
+## Pull request process
+
+- Authors should use a valid email account when committing.
+- Make clear and concise commits (1 commit per 1 feature or issue)
+- Authors are responsible for breaking down the PR into sensible commits (with proper commit messages)
+- Avoid using force push when addressing comments and review items.
+- Maintainers shall use 'rebase and merge' to make sure all commits can apply cleanly onto the master branch
+- Maintainers shall only use 'squash and merge' with the permission of the authors.

COPYING

@@ -1,44 +1,32 @@
-Copyright 2001-2023 Xiph.Org, Skype Limited, Octasic,
-                    Jean-Marc Valin, Timothy B. Terriberry,
-                    CSIRO, Gregory Maxwell, Mark Borgerding,
-                    Erik de Castro Lopo, Mozilla, Amazon
+BSD 3-Clause Clear License The Clear BSD License
 
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions
-are met:
+Copyright (c) Alliance for Open Media
 
-- Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
+All rights reserved.
 
-- Redistributions in binary form must reproduce the above copyright
-notice, this list of conditions and the following disclaimer in the
-documentation and/or other materials provided with the distribution.
-
-- Neither the name of Internet Society, IETF or IETF Trust, nor the
-names of specific contributors, may be used to endorse or promote
-products derived from this software without specific prior written
-permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
-OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
-LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+Redistribution and use in source and binary forms, with or without modification,
+are permitted (subject to the limitations in the disclaimer below) provided that
+the following conditions are met:
 
-Opus is subject to the royalty-free patent licenses which are
-specified at:
+1. Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
 
-Xiph.Org Foundation:
-https://datatracker.ietf.org/ipr/1524/
+2. Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in
+the documentation and/or other materials provided with the distribution.
 
-Microsoft Corporation:
-https://datatracker.ietf.org/ipr/1914/
+3. Neither the name of the Alliance for Open Media nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
 
-Broadcom Corporation:
-https://datatracker.ietf.org/ipr/1526/
+
+NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED BY THIS LICENSE.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

LICENSE_PLEASE_READ.txt

@@ -0,0 +1,44 @@
+Copyright 2001-2023 Xiph.Org, Skype Limited, Octasic,
+                    Jean-Marc Valin, Timothy B. Terriberry,
+                    CSIRO, Gregory Maxwell, Mark Borgerding,
+                    Erik de Castro Lopo, Mozilla, Amazon
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+- Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+
+- Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+
+- Neither the name of Internet Society, IETF or IETF Trust, nor the
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Opus is subject to the royalty-free patent licenses which are
+specified at:
+
+Xiph.Org Foundation:
+https://datatracker.ietf.org/ipr/1524/
+
+Microsoft Corporation:
+https://datatracker.ietf.org/ipr/1914/
+
+Broadcom Corporation:
+https://datatracker.ietf.org/ipr/1526/

OPUS_LICENSE

@@ -0,0 +1,139 @@
+# liboac
+
+## Introduction
+
+liboac is the reference implementation of the Open Audio Codec (OAC) specification.
+
+OAC intends to be the successor to [Opus](https://tools.ietf.org/html/rfc6716) and liboac is based on [libopus](https://gitlab.xiph.org/xiph/opus). Both are works in progress.
+
+This package implements a shared library for encoding and decoding raw OAC
+bitstreams. It also includes a number of test tools used for testing the
+correct operation of the library. The bitstreams read/written by these
+tools should not be used for OAC file distribution: they include
+additional debugging data and cannot support seeking.
+
+## Software License
+
+Modifications and additions made to the software by the Alliance for Open Media are licensed as specified in (COPYING)[./COPYING].
+
+See the git commit logs for a list of modifications.
+
+The libopus COPYING file is preserved as (OPUS_LICENSE)[./OPUS_LICENSE].
+
+## Compiling
+
+To build from a distribution tarball, you only need to do the following:
+
+    % ./configure
+    % make
+
+To build from the git repository, the following steps are necessary:
+
+0. Set up a development environment:
+
+On an Ubuntu or Debian family Linux distribution:
+
+    % sudo apt-get install git autoconf automake libtool gcc make
+
+On a Fedora/Redhat based Linux:
+
+    % sudo dnf install git autoconf automake libtool gcc make
+
+Or for older Redhat/Centos Linux releases:
+
+    % sudo yum install git autoconf automake libtool gcc make
+
+On Apple macOS, install Xcode and brew.sh, then in the Terminal enter:
+
+    % brew install autoconf automake libtool
+
+1. Clone the repository:
+
+    % git clone https://github.com/AOMediaCodec/oac.git
+    % cd oac
+
+2. Compiling the source
+
+    % ./autogen.sh
+    % ./configure
+    % make
+
+On x86, it's a good idea to use a -march= option that allows the use of AVX2.
+
+3. Install the codec libraries (optional)
+
+    % sudo make install
+
+Once you have compiled the codec, there will be a oac_demo executable
+in the top directory.
+
+```
+Usage: oac_demo [-e] <application> <sampling rate (Hz)> <channels (1/2)>
+         <bits per second> [options] <input> <output>
+       oac_demo -d <sampling rate (Hz)> <channels (1/2)> [options]
+         <input> <output>
+
+mode: voip | audio | restricted-lowdelay
+options:
+  -e                : only runs the encoder (output the bit-stream)
+  -d                : only runs the decoder (reads the bit-stream as input)
+  -cbr              : enable constant bitrate; default: variable bitrate
+  -cvbr             : enable constrained variable bitrate; default:
+                      unconstrained
+  -bandwidth <NB|MB|WB|SWB|FB>
+                    : audio bandwidth (from narrowband to fullband);
+                      default: sampling rate
+  -framesize <2.5|5|10|20|40|60>
+                    : frame size in ms; default: 20
+  -max_payload <bytes>
+                    : maximum payload size in bytes, default: 1024
+  -complexity <comp>
+                    : complexity, 0 (lowest) ... 10 (highest); default: 10
+  -inbandfec        : enable SILK inband FEC
+  -forcemono        : force mono encoding, even for stereo input
+  -dtx              : enable SILK DTX
+  -loss <perc>      : simulate packet loss, in percent (0-100); default: 0
+```
+
+input and output are little-endian signed 16-bit PCM files or OAC
+bitstreams with simple oac_demo custom framing.
+
+## Testing
+
+This package includes a collection of automated unit and system tests
+which SHOULD be run after compiling the package especially the first
+time it is run on a new platform.
+
+To run the integrated tests:
+
+    % make check
+
+## Compiling liboac for Windows and alternative build systems
+
+See cmake/README.md or meson/README.md.
+
+## Portability notes
+
+This implementation uses floating-point by default but can be compiled to
+use only fixed-point arithmetic by setting --enable-fixed-point (if using
+autoconf) or by defining the FIXED_POINT macro (if building manually).
+The fixed point implementation has somewhat lower audio quality and is
+slower on platforms with fast FPUs, it is normally only used in embedded
+environments.
+
+The implementation can be compiled with any compiler supporting C89 or later.
+While it does not rely on any _undefined behavior_ as defined by C89 or
+C99, it relies on common _implementation-defined behavior_ for two's
+complement architectures:
+
+- Right shifts of negative values are consistent with two's complement
+  arithmetic, so that a>>b is equivalent to floor(a/(2^b)),
+
+- For conversion to a signed integer of N bits, the value is reduced modulo 2^N
+  to be within range of the type,
+
+- The result of integer division of a negative value is truncated towards zero,
+  and
+
+- The compiler provides a 64-bit integer type (a C99 requirement which is
+  supported by most C89 compilers).