tag	47009ecbc6f323cbaac245aa31abe857ec9189df
tagger	Urvang Joshi <urvang@google.com>	Fri Dec 19 14:22:49 2025 -0800
object	f25e5ac20227de3e32059dd9cf8a596e62ac5180

Research-v13.0.0 anchor.

Includes the following since the previous anchor:

Candidate Tools
---------------
- CWG-F381 "Bugfix for CfL modes with large block sizes”
- CWG-F387 “Training of the context initialization tables”
- CWG-F389 "Fix Coeff Precision after TCQ" (solution 2)
- CWG-F393 “DIP Context Initialization Fix”
- CWG-F400 "BugFix of Warp Modes"
- CWG-F401 "Handling of Refined MV and Reference Padding in Sub-8x8 Chroma"
- Deblock filter sub-PU boundaries for OPFL chroma and for DMVR 16×8 and 8×16 cases
- CWG-F406 "Bug fix for WARP_CAUSAL mode"
- CWG-F426 "Deblocking issues cleanup"
- CWG-F425 "Remove offset-based refinement of intra prediction (ORIP)"
- CWG-F416 "Guided Detail Filter: Gradient Sample Support”
- CWG-F415 "Quantization Matrix Changes"
- CWG-F421 "Intra BAWP condition checks"
- Revert the aspect 4 in F303 for MHCCP division

High-level Syntax
-----------------
- CWG-F233 “Picture struct and Scan type metadata”
- CWG-F255 "Quantization matrix OBU”
- CWG-F153 "Film grain model OBU"
- CWG-F024 “New Key Frame OBUs in AVM”
- CWG-F377 "Sequence Header OBU Changes for reduced_still_picture_header"
- CWG-F356 "Clarification for the show existing frame obu"
- CONFIG_MULTI_LEVEL_SEGMENTATION implementation (Follow-up for CWG-E242)
- Add LCR, Atlas id in the SH and its activation (harmonization of previous proposals)
- CWG-F405 "Removal of Redundant Tile-related Information Signaling in TIP Direct Output Mode”
- CWG-F395 "On the signaling of cross frame CDF initialization"
- CWG-F412 "On sequence header coding tool parameters grouping"
- CWG-F418 "A cleanup of frame level signaling”
- CWG-F419 "On the frame level signaling of the screen content and Intra-BC parameters"
- CWG-F411 "Alpha signalling in the multistream atlas metadata"
- CWG-F417 "More Sequence Header OBU Changes for single_picture_header_flag"
- CWG-F402 "Modifications to the sequence header”
- CWG-F432 "Resolving FGS dependency on CI OBU”
- CWG-F427 "On the signaling of the sequencer header identifier in a bridge frame OBU”
- CWG-F433 "Sequence Header Syntax Reorganization"
- CWG-F430 "On Temporal Point Info Metadata”
- CWG-F322 "Restricted Switch OBU”
- CWG-F270 "Content Interpretation OBU"
- CWG-F446 “Signalling Film Grain Parameters”
- CWG-F436 "Temporal units in AV2" (some parts)

Encoder-only Improvements (Non-normative)
-----------------------------------------
- CWG-F410 “Encoder-only: Transform Partition Search Improvement for Inter Blocks”
- CWG-F383 "Pyramid Quantization Offsets Adjustment for AVM in LD mode"

Encoder / Decoder Speedups (Non-normative)
------------------------------------------
- Add AVX2 for mhccp_predict_hv_hbd()
- Enable row multi-threading by default in decoder
- Enable CDEF and CCSO MT
- Improve and enable Loop restoration frame MT
- Remove redundant memset of mhccp_ref_buf_q3 buffer
- Add frame level lossless check to CDEF and loop filter
- Add AVX2 for mhccp_derive_multi_param_hv()
- Add AVX2 for refinemv_highbd_pad_mc_border for b_w = 11
- Optimize ccso_pre_compute_class_err()
- Optimize AVX2 of av2_highbd_dist_wtd_convolve_2d()
- Optimize av2_opfl_mv_refinement_nxn() for block width 8

Code Cleanups
-------------
- intrapred: remove unused upsample_above/left variables/params
- Unused code cleanup
- CWG-F407 “Code Cleanup: Symbol Renaming in AVM”
- Removal of the compile time flags

Bugfixes
--------
https://gitlab.com/AOMediaCodec/avm/-/milestones/17#tab-issues

High-level Syntax tools NOT included in this anchor (but will be included in next anchor)
-----------------------------------------------------------------------------------------
- CWG-F428 "On level constraints for AV2 specification"
- CWG-F408 "On levels for the AV2 specification" (aspects A, B, F)
- CWG-F431 "HLS changes associated with pictures that are decoded but not used for display"
- CWG-F359 "Buffer handling of frames with Global IBC and In-loop filters enabled”
- CWG-F429 "On maximum layer capacity in OPS, LCR and SH"
- CWG-F436 "Temporal units in AV2"  (some parts)
- CWG-F438 "Remove incomplete metadata types"
- CWG-F414 "On OBU extensibility and trailing bits"
- CWG-F440 "On Decoded Frame Hash Metadata"
- CWG-F441 "Support for higher frame rates in AV2"
- CWG-F447 “Dependency Map Mechanism and Metadata Persistence”
- CWG-F444 “Bug Fix: Modify CICP constraint in the uncompressed header”
- CWG-F449 “FG15 recommendation on the presence of the MSDO, LCR and OPS in different profiles”

commit	f25e5ac20227de3e32059dd9cf8a596e62ac5180	[log] [tgz]
author	Urvang Joshi <urvang@google.com>	Fri Dec 19 19:43:06 2025 +0000
committer	Urvang Joshi <urvang@google.com>	Fri Dec 19 19:43:06 2025 +0000
tree	3767b39907b732d2bd501a7ddc7bc7a9d7da1537
parent	e897e5bdf66cba8ca7d0b8f7849203f995d26f72 [diff]

Add `avm` or `av2` prefix to a few more symbols

* highbd_warp_plane --\> av2_highbd_warp_plane
* ransac --\> avm_ransac

Note: only symbols are renamed; filenames remain the same.

Related to #150

7 files changed

tree: 3767b39907b732d2bd501a7ddc7bc7a9d7da1537

README.md

AVM

Building

Prerequisites

CMake version 3.16 or higher.
Git.
Perl.
For x86 targets, yasm, which is preferred, or a recent version of nasm. If you download yasm with the intention to work with Visual Studio, please download win32.exe or win64.exe and rename it into yasm.exe. DO NOT download or use vsyasm.exe.
Building the documentation requires doxygen version 1.8.10 or newer.
Building the unit tests requires Python.

Get the code

The AVM project source code is stored in the Alliance of Open Media’s GitLab repository. To get the code,

    $ git clone https://gitlab.com/AOMediaCodec/avm.git
    # By default, the above command stores the source in the avm directory:
    $ cd avm

Basic build

CMake replaces the configure step typical of many projects. Running CMake will produce configuration and build files for the currently selected CMake generator. For most systems the default generator is Unix Makefiles. The basic form of a makefile build is the following:

    $ cmake path/to/avm
    $ make

The above will generate a makefile build that produces the AVM library and applications for the current host system after the make step completes successfully. The compiler chosen varies by host platform, but a general rule applies: On systems where cc and c++ are present in $PATH at the time CMake is run the generated build will use cc and c++ by default.

Configuration options

The AVM codec library has a great many configuration options. These come in two varieties:

Build system configuration options. These have the form ENABLE_FEATURE.
AVM codec configuration options. These have the form CONFIG_FEATURE.

Both types of options are set at the time CMake is run. The following example enables ccache and disables the AVM encoder:

    $ cmake path/to/avm -DENABLE_CCACHE=1 -DCONFIG_MULTITHREAD=0
    $ make

The available configuration options are too numerous to list here. Build system configuration options can be found at the top of the CMakeLists.txt file found in the root of the AVM repository, and AVM codec configuration options can currently be found in the file build/cmake/avm_config_defaults.cmake.

Dylib builds

A dylib (shared object) build of the AVM codec library can be enabled via the CMake built in variable BUILD_SHARED_LIBS:

    $ cmake path/to/avm -DBUILD_SHARED_LIBS=1
    $ make

This is currently only supported on non-Windows targets.

Debugging

Depending on the generator used there are multiple ways of going about debugging AVM components. For single configuration generators like the Unix Makefiles generator, setting CMAKE_BUILD_TYPE to Debug is sufficient:

    $ cmake path/to/avm -DCMAKE_BUILD_TYPE=Debug

For Xcode, mainly because configuration controls for Xcode builds are buried two configuration windows deep and must be set for each subproject within the Xcode IDE individually, CMAKE_CONFIGURATION_TYPES should be set to Debug:

    $ cmake path/to/avm -G Xcode -DCMAKE_CONFIGURATION_TYPES=Debug

For Visual Studio the in-IDE configuration controls should be used. Simply set the IDE project configuration to Debug to allow for stepping through the code.

In addition to the above it can sometimes be useful to debug only C and C++ code. To disable all assembly code and intrinsics set AVM_TARGET_CPU to generic at generation time:

    $ cmake path/to/avm -DAVM_TARGET_CPU=generic

Cross compiling

For the purposes of building the AVM codec and applications, relative to the scope of this guide, all builds for architectures differing from the native host architecture will be considered cross compiles. The AVM CMake build handles cross compiling via the use of toolchain files included in the AVM repository. The available toolchain files can be found at cmake folder in the AVM repository. The following example demonstrates use of the x86-linux.cmake toolchain file on a x86_64 linux host:

    $ cmake path/to/avm \
      -DCMAKE_TOOLCHAIN_FILE=path/to/avm/build/cmake/toolchains/x86-linux.cmake
    $ make

Sanitizers

Sanitizer integration is built-in to the CMake build system. To enable a sanitizer, add -DSANITIZE=<type> to the CMake command line. For example, to enable address sanitizer:

    $ cmake path/to/avm -DSANITIZE=address
    $ make

Sanitizers available vary by platform, target, and compiler. Consult your compiler documentation to determine which, if any, are available.

Microsoft Visual Studio builds

Building the AVM codec library in Microsoft Visual Studio is supported. Visual Studio 2019 (16.7) or later is required. The following example demonstrates generating projects and a solution for the Microsoft IDE:

    # This does not require a bash shell; Command Prompt (cmd.exe) is fine.
    # This assumes the build host is a Windows x64 computer.

    # To build with Visual Studio 2019 for the x64 target:
    $ cmake path/to/avm -G "Visual Studio 16 2019"
    $ cmake --build .

    # To build with Visual Studio 2019 for the 32-bit x86 target:
    $ cmake path/to/avm -G "Visual Studio 16 2019" -A Win32
    $ cmake --build .

NOTE: The build system targets Windows 7 or later by compiling files with -D_WIN32_WINNT=0x0601.

Xcode builds

Building the AVM codec library in Xcode is supported. The following example demonstrates generating an Xcode project:

    $ cmake path/to/avm -G Xcode

Build with VMAF support

After installing libvmaf.a, you can use it with the encoder:

    $ cmake path/to/avm -DCONFIG_TUNE_VMAF=1

Please note that the default VMAF model will be used unless you set the following flag when running the encoder:

    # --vmaf-model-path=path/to/model

Testing

Testing basics

There are several methods of testing the AVM codec. All of these methods require the presence of the AVM source code and a working build of the AVM library and applications.

1. Unit tests:

The unit tests can be run at build time:

    # Before running the make command the LIBAVM_TEST_DATA_PATH environment
    # variable should be set to avoid downloading the test files to the
    # cmake build configuration directory.
    $ cmake path/to/avm
    # Note: The AVM CMake build creates many test targets. Running make
    # with multiple jobs will speed up the test run significantly.
    $ make runtests

2. Example tests:

The example tests require a bash shell and can be run in the following manner:

    # See the note above about LIBAVM_TEST_DATA_PATH above.
    $ cmake path/to/avm
    $ make
    # It's best to build the testdata target using many make jobs.
    # Running it like this will verify and download (if necessary)
    # one at a time, which takes a while.
    $ make testdata
    $ path/to/avm/test/examples.sh --bin-path examples

Downloading the test data

The fastest and easiest way to obtain the test data is to use CMake to generate a build using the Unix Makefiles generator, and then to build only the testdata rule:

    $ cmake path/to/avm -G "Unix Makefiles"
    # 28 is used because there are 28 test files as of this writing.
    $ make -j28 testdata

The above make command will only download and verify the test data.

Additional input data for testing the encoder can be obtained from: AV2 - CTC

Sharded testing

The AVM codec library unit tests are built upon gtest which supports sharding of test jobs. Sharded tests can be achieved as follows for example:

   # Set the environment variable GTEST_TOTAL_SHARDS to control the number of
   # shards.
   $ export GTEST_TOTAL_SHARDS=10
   # (GTEST shard indexing is 0 based).
   $ seq 0 $(( $GTEST_TOTAL_SHARDS - 1 )) \
       | xargs -n 1 -P 0 -I{} env GTEST_SHARD_INDEX={} ./test_libavm

To create a test shard for each CPU core available on the current system set GTEST_TOTAL_SHARDS to the number of CPU cores on your system minus one. The maximum number of test targets that can run concurrently is determined by the number of CPUs on the system where the build is configured as detected by CMake. A system with 24 cores can run 24 test shards using a value of 24 with the -j parameter. When CMake is unable to detect the number of cores 10 shards is the default maximum value.

Coding style

We are using the Google C Coding Style defined by the Google C++ Style Guide.

The coding style used by this project is enforced with clang-format and cmake-format.

clang-format can be installed with your system's package manager, or directly from llvm.org. For best results, your version should match the one used by Gitlab CI, noted as a comment in .clang-format.
cmake-format can be obtained by installing cmakelang. Again, for best results, your version should match the one used by Gitlab CI, noted as a comment in .cmake-format.py

Before pushing changes for review, format your code using the tools above.

We recommend automating the formatting by adding a pre-commit hook at .git/hooks/pre-commit. An example pre-commit hook is provided below:

#!/bin/bash
# Replace 'VERSION' below to match clang-format version in the CI.
CLANG_FORMAT_PATH=/usr/lib/llvm-VERSION/bin
CMAKE_FORMAT_PATH=${HOME}/.local/bin/

echo "Applying clang-format ..."
for file in $(git diff-index --cached --name-only HEAD -- "*.[hc]pp" "*.cc" "*.[ch]") ; do
  ${CLANG_FORMAT_PATH}/clang-format -i --style=file ${file}
  git add ${file}
  echo "Formatted file: $file"
done
echo "Done."

echo "Applying cmake-format ..."
for file in $(git diff-index --cached --name-only HEAD -- '*.cmake' CMakeLists.txt) ; do
  ${CMAKE_FORMAT_PATH}/cmake-format -i ${file}
  git add ${file}
  echo "Formatted file: $file"
done
echo "Done."

Submitting patches

We manage the submission of patches using Gitlab's merge request process. This tool implements a workflow on top of the Git version control system to ensure that all changes get peer reviewed and tested prior to their distribution. If you are not able to submit an MR, please contact SW coordinators to make sure necessary contributor agreements are signed for the AOMedia Project.

Follow the one-time set-up steps as detailed here.
For pushing your code modifications, follow the steps detailed here.
Once the code is pushed into a branch, create a merge request as detailed here.
- The code review, approval and CI/CD process will be initiated after the MR is created.
- Once the MR is approved, the software co-ordinators will merge the MR to the main branch.

Follow the Merge request page to check the status of the changes, review comments etc.

Support

This library is an open source project supported by its community. Please email https://aomedia.org/contact/ for help.

Bug reports

Bug reports can be filed in the Alliance for Open Media Gitlab issue tracker.