ampas / Aces Dev

Academy Color Encoding System Developer Resources

The Academy Color Encoding System (ACES) is a set of components that facilitates a wide range of motion picture and television workflows while eliminating the ambiguity of legacy file formats. The system is designed to support both all-digital and hybrid film-digital motion picture workflows.

The basic ACES components are:

• Color encoding and metric specifications, file format specifications, color transformations, and an open source reference implementation
• A set of reference images and calibration targets for film scanners and recorders
• Documentation on the system and software tools

This toolkit is intended to serve as a distribution mechanism for key components of the system, including the reference implementation transforms, reference images, and documentation.

Package Contents

• documents/ – ACES-related documents
• formats/ - ACES file formats code and examples
• images/ - "golden" images created using the reference implementation transforms
• transforms/ - ACES reference implementation transforms

Changes from Previous Release

Though the "master" branch is 1.2, the current major version of ACES remains 1. This means the 1.2 update adds a number of transforms but does not change the look or modify the existing core transforms (beyond addressing reported bugs and/or inconsequential formatting/whitespace changes).

As always, you should check the hotfixes and dev branches for the latest bug fixes and new features that will ultimately be rolled into a future version of ACES. Improvements will continue to be staged on the dev branch for testing as they become available.

Included in ACES 1.2:

• New Features:
  • Add ACES Metadata File specification document (S-2019-001), XML schema, and example files
  • Add new version of Common LUT Format specification document (S-2014-006)
  • Add new ACES Project Organization and Development Procedure document (P-2019-001)
  • Add ACES Color Space Conversion transforms between:
    • ACES and Canon Canon Log 2 Cinema Gamut
    • ACES and Canon Canon Log 3 Cinema Gamut
    • ACES and ARRI ALEXA LogC (EI800) WideGamut
    • ACES and RED Log3G10 REDWideGamutRGB
    • ACES and Sony S-Log3 S-Gamut3
    • ACES and Sony S-Log3 S-Gamut3.Cine
    • ACES and Panasonic Varicam V-Log V-Gamut
  • Add HDR Output Transforms (RRT+ODT):
    • P3D65 (1000 cd/m^2) ST.2084 (and inverse)
    • P3D65 (2000 cd/m^2) ST.2084 (and inverse)
    • P3D65 (4000 cd/m^2) ST.2084 (and inverse)
  • Add vendor-supplied IDTs for Sony VENICE
• Other:
  • Update ACES System Versioning document (S-2014-002)
  • Update TransformIDs of ACES reference implementation transforms
  • Remove "Academy Color Encoding System (ACES) Clip-level Metadata File Format Definition and Usage" (TB-2014-009)
  • Add reference images to accompany new ACEScsc transforms

For a more detailed list of changes see the CHANGELOG and in the commit history.

Notes on the new ACES Metadata Files (AMF) specification

ACES 1.2 includes the new ACES Metadata File (AMF) specification that replaces the ACES Clip-level Metadata File Format (ACESclip). AMF is documented in Academy Specification S-2019-001 and TB-2014-009 has been retracted. AMF offers a simplified means to describe the transforms necessary to configure an ACES viewing pipeline for a collection of related ACES image files. AMF supports a mechanism to communicate the ACES Look Transforms and the working color space in which ASC-CDL based Looks are applied enabling the communication of Look information throughout production and post-production. A series of new ACES Color Space Conversion (ACEScsc) transforms have been added with the expectation that these transforms may be useful working spaces for the application of ACES ASC-CDL based Look Transforms. Also included in the release is an XML schema for the AMF and example AMF files.

Notes on the updated Common LUT Format (CLF) specification

ACES 1.2 also includes an updated version of the Common LUT Format (CLF) specification. This new version includes changes based on feedback from the ACES community. It adds additional operators to the specification and the document has been substantially revised to more clearly communicate its intent.

Notes on the updated ACES System Versioning Documentation

The ACES System Versioning Documentation has been updated to support additional vendor- and user-supplied transform types, improve TransformID format consistency, version control for the TransformID format, and to provide a means for automated systems to recognize the presence of ACES TransformIDs and identify their version. All transforms in the ACES reference implementation have been updated to conform to the new TransformID format.

Notes on the new ACES Project Organization and Development Procedure

In early 2019, ACES leadership established a revised organizational structure and development procedures for the ACES project. The new structure and development procedures were modeled after those adopted by the Academy Software Foundation, with the goals of increasing visibility into the development of ACES, enabling greater global participation in the ACES development process, providing accountability mechanisms, and better documenting the decision making process. The revised structure and development procedures are detailed in Academy Procedure P-2019-001.

Versioning

The links to the current and all past versions of the ACES Developer Resources can be found at https://github.com/ampas/aces-dev/releases.

Source code is version controlled using the git version control system and hosted on GitHub at https://github.com/ampas/aces-dev/.

Individual files now conform to the ACES System Versioning Specification. Details can be found in the Academy Specification "S-2014-002 - Academy Color Encoding System - Versioning System" included in documents/

Branch Structure

Master Branch

The current release version of ACES can always be found at the HEAD of the master branch. The master branch contains no intermediate commits and all commits on the master branch are tagged to represent a release of ACES.

Dev Branch

Intermediate commits between releases will be staged on the dev branch. Commits staged on the dev branch, but not yet merged into the master, should be considered as "planned for inclusion" in the next release version. Commits on the dev branch will ultimately be merged into the master branch as part of a future release.

Hotfixes Branch

In some instances it may be necessary to create a hotfixes branch. The hotfixes branch will include important, but not fully tested, fixes for bugs found in a particular release. Hotfixes should only be implemented by developers if the bug they are intending to correct is encountered in the course of production and is deemed to be a barrier to using a particular ACES release. Hotfixes, once fully tested, will be merged into the dev branch, and ultimately the master.

Prerequisites

Color Transformation Language

Color Transformation Language (CTL) can be downloaded from https://github.com/ampas/CTL

License Terms for Academy Color Encoding System Components

Academy Color Encoding System (ACES) software and tools are provided by the Academy under the following terms and conditions: A worldwide, royalty-free, non-exclusive right to copy, modify, create derivatives, and use, in source and binary forms, is hereby granted, subject to acceptance of this license.

Copyright 2019 Academy of Motion Picture Arts and Sciences (A.M.P.A.S.). Portions contributed by others as indicated. All rights reserved.

Performance of any of the aforementioned acts indicates acceptance to be bound by the following terms and conditions:

• Copies of source code, in whole or in part, must retain the above copyright notice, this list of conditions and the Disclaimer of Warranty.

• Use in binary form must retain the above copyright notice, this list of conditions and the Disclaimer of Warranty in the documentation and/or other materials provided with the distribution.

• Nothing in this license shall be deemed to grant any rights to trademarks, copyrights, patents, trade secrets or any other intellectual property of A.M.P.A.S. or any contributors, except as expressly stated herein.

• Neither the name "A.M.P.A.S." nor the name of any other contributors to this software may be used to endorse or promote products derivative of or based on this software without express prior written permission of A.M.P.A.S. or the contributors, as appropriate.

This license shall be construed pursuant to the laws of the State of California, and any disputes related thereto shall be subject to the jurisdiction of the courts therein.

Disclaimer of Warranty: THIS SOFTWARE IS PROVIDED BY A.M.P.A.S. AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT ARE DISCLAIMED. IN NO EVENT SHALL A.M.P.A.S., OR ANY CONTRIBUTORS OR DISTRIBUTORS, BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, RESITUTIONARY, 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.

WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, THE ACADEMY SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS OR WARRANTIES WHATSOEVER RELATED TO PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS IN THE ACADEMY COLOR ENCODING SYSTEM, OR APPLICATIONS THEREOF, HELD BY PARTIES OTHER THAN A.M.P.A.S.,WHETHER DISCLOSED OR UNDISCLOSED.