diff options
Diffstat (limited to 'third_party/aom/README.md')
| -rw-r--r-- | third_party/aom/README.md | 282 |
1 files changed, 274 insertions, 8 deletions
diff --git a/third_party/aom/README.md b/third_party/aom/README.md index acedb105c..f5446f9d9 100644 --- a/third_party/aom/README.md +++ b/third_party/aom/README.md @@ -1,5 +1,44 @@ # AV1 Codec Library +## Contents +1. [Building the lib and applications](#building-the-library-and-applications) + - [Prerequisites](#prerequisites) + - [Get the code](#get-the-code) + - [Basics](#basic-build) + - [Configuration options](#configuration-options) + - [Dylib builds](#dylib-builds) + - [Debugging](#debugging) + - [Cross compiling](#cross-compiling) + - [Sanitizer support](#sanitizers) + - [MSVC builds](#microsoft-visual-studio-builds) + - [Xcode builds](#xcode-builds) + - [Emscripten builds](#emscripten-builds) + - [Extra Build Flags](#extra-build-flags) +2. [Testing the library](#testing-the-av1-codec) + - [Basics](#testing-basics) + - [Unit tests](#1_unit-tests) + - [Example tests](#2_example-tests) + - [Encoder tests](#3_encoder-tests) + - [IDE hosted tests](#ide-hosted-tests) + - [Downloading test data](#downloading-the-test-data) + - [Adding a new test data file](#adding-a-new-test-data-file) + - [Additional test data](#additional-test-data) + - [Sharded testing](#sharded-testing) + - [Running tests directly](#1_running-test_libaom-directly) + - [Running tests via CMake](#2_running-the-tests-via-the-cmake-build) +3. [Coding style](#coding-style) +4. [Submitting patches](#submitting-patches) + - [Login cookie](#login-cookie) + - [Contributor agreement](#contributor-agreement) + - [Testing your code](#testing-your-code) + - [Commit message hook](#commit-message-hook) + - [Upload your change](#upload-your-change) + - [Incorporating Reviewer Comments](#incorporating-reviewer-comments) + - [Submitting your change](#submitting-your-change) + - [Viewing change status](#viewing-the-status-of-uploaded-changes) +5. [Support](#support) +6. [Bug reports](#bug-reports) + ## Building the library and applications ### Prerequisites @@ -14,6 +53,17 @@ 7. Emscripten builds require the portable [EMSDK](https://kripken.github.io/emscripten-site/index.html). +### Get the code + +The AV1 library source code is stored in the Alliance for Open Media Git +repository: + +~~~ + $ git clone https://aomedia.googlesource.com/aom + # By default, the above command stores the source in the aom directory: + $ cd aom +~~~ + ### Basic build CMake replaces the configure step typical of many projects. Running CMake will @@ -21,8 +71,10 @@ 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/aom $ make +~~~ The above will generate a makefile build that produces the AV1 library and applications for the current host system after the make step completes @@ -39,10 +91,10 @@ varieties: 2. AV1 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 high bit depth: +enables ccache and disables the AV1 encoder: ~~~ - $ cmake path/to/aom -DENABLE_CCACHE=1 -DCONFIG_HIGHBITDEPTH=0 + $ cmake path/to/aom -DENABLE_CCACHE=1 -DCONFIG_AV1_ENCODER=0 $ make ~~~ @@ -102,8 +154,10 @@ The toolchain files available at the time of this writing are: - arm64-ios.cmake - arm64-linux-gcc.cmake + - arm64-mingw-gcc.cmake - armv7-ios.cmake - armv7-linux-gcc.cmake + - armv7-mingw-gcc.cmake - armv7s-ios.cmake - mips32-linux-gcc.cmake - mips64-linux-gcc.cmake @@ -194,11 +248,11 @@ appropriately using the emsdk\_env script. -DENABLE_CCACHE=1 \ -DAOM_TARGET_CPU=generic \ -DENABLE_DOCS=0 \ + -DENABLE_TESTS=0 \ -DCONFIG_ACCOUNTING=1 \ -DCONFIG_INSPECTION=1 \ -DCONFIG_MULTITHREAD=0 \ -DCONFIG_RUNTIME_CPU_DETECT=0 \ - -DCONFIG_UNIT_TESTS=0 \ -DCONFIG_WEBM_IO=0 \ -DCMAKE_TOOLCHAIN_FILE=path/to/emsdk-portable/.../Emscripten.cmake ~~~ @@ -217,12 +271,32 @@ appropriately using the emsdk\_env script. $ path/to/AOMAnalyzer path/to/examples/inspect.js path/to/av1/input/file ~~~ +### Extra build flags + +Three variables allow for passing of additional flags to the build system. + +- AOM\_EXTRA\_C\_FLAGS +- AOM\_EXTRA\_CXX\_FLAGS +- AOM\_EXTRA\_EXE\_LINKER\_FLAGS + +The build system attempts to ensure the flags passed through the above variables +are passed to tools last in order to allow for override of default behavior. +These flags can be used, for example, to enable asserts in a release build: + +~~~ + $ cmake path/to/aom \ + -DCMAKE_BUILD_TYPE=Release \ + -DAOM_EXTRA_C_FLAGS=-UNDEBUG \ + -DAOM_EXTRA_CXX_FLAGS=-UNDEBUG +~~~ ## Testing the AV1 codec ### Testing basics -Currently there are two types of tests in the AV1 codec repository. +There are several methods of testing the AV1 codec. All of these methods require +the presence of the AV1 source code and a working build of the AV1 library and +applications. #### 1. Unit tests: @@ -253,6 +327,57 @@ The example tests require a bash shell and can be run in the following manner: $ path/to/aom/test/examples.sh --bin-path examples ~~~ +#### 3. Encoder tests: + +When making a change to the encoder run encoder tests to confirm that your +change has a positive or negligible impact on encode quality. When running these +tests the build configuration should be changed to enable internal encoder +statistics: + +~~~ + $ cmake path/to/aom -DCONFIG_INTERNAL_STATS=1 + $ make +~~~ + +The repository contains scripts intended to make running these tests as simple +as possible. The following example demonstrates creating a set of baseline clips +for comparison to results produced after making your change to libaom: + +~~~ + # This will encode all Y4M files in the current directory using the + # settings specified to create the encoder baseline statistical data: + $ cd path/to/test/inputs + # This command line assumes that run_encodes.sh, its helper script + # best_encode.sh, and the aomenc you intend to test are all within a + # directory in your PATH. + $ run_encodes.sh 200 500 50 baseline +~~~ + +After making your change and creating the baseline clips, you'll need to run +encodes that include your change(s) to confirm that things are working as +intended: + +~~~ + # This will encode all Y4M files in the current directory using the + # settings specified to create the statistical data for your change: + $ cd path/to/test/inputs + # This command line assumes that run_encodes.sh, its helper script + # best_encode.sh, and the aomenc you intend to test are all within a + # directory in your PATH. + $ run_encodes.sh 200 500 50 mytweak +~~~ + +After creating both data sets you can use `test/visual_metrics.py` to generate a +report that can be viewed in a web browser: + +~~~ + $ visual_metrics.py metrics_template.html "*stt" baseline mytweak \ + > mytweak.html +~~~ + +You can view the report by opening mytweak.html in a web browser. + + ### IDE hosted tests By default the generated projects files created by CMake will not include the @@ -283,6 +408,25 @@ rule: The above make command will only download and verify the test data. +### Adding a new test data file + +First, add the new test data file to the `aom-test-data` bucket of the +`aomedia-testing` project on Google Cloud Platform. You may need to ask someone +with the necessary access permissions to do this for you. + +Once the new test data file has been added to `aom-test-data`, create a CL to +add the name of the new test data file to `test/test_data_util.cmake` and add +the SHA1 checksum of the new test data file to `test/test-data.sha1`. (The SHA1 +checksum of a file can be calculated by running the `sha1sum` command on the +file.) + +### Additional test data + +The test data mentioned above is strictly intended for unit testing. + +Additional input data for testing the encoder can be obtained from: +https://media.xiph.org/video/derf/ + ### Sharded testing The AV1 codec library unit tests are built upon gtest which supports sharding of @@ -291,9 +435,10 @@ test jobs. Sharded test runs can be achieved in a couple of ways. #### 1. Running test\_libaom directly: ~~~ - # Set the environment variable GTEST_TOTAL_SHARDS to 9 to run 10 test shards + # Set the environment variable GTEST_TOTAL_SHARDS to control the number of + # shards. + $ export GTEST_TOTAL_SHARDS=10 # (GTEST shard indexing is 0 based). - $ export GTEST_TOTAL_SHARDS=9 $ seq 0 $(( $GTEST_TOTAL_SHARDS - 1 )) \ | xargs -n 1 -P 0 -I{} env GTEST_SHARD_INDEX={} ./test_libaom ~~~ @@ -322,8 +467,20 @@ is the default maximum value. ## Coding style +We are using the Google C Coding Style defined by the +[Google C++ Style Guide](https://google.github.io/styleguide/cppguide.html). + The coding style used by this project is enforced with clang-format using the -configuration contained in the .clang-format file in the root of the repository. +configuration contained in the +[.clang-format](https://chromium.googlesource.com/webm/aom/+/master/.clang-format) +file in the root of the repository. + +You can download clang-format using your system's package manager, or directly +from [llvm.org](http://llvm.org/releases/download.html). You can also view the +[documentation](https://clang.llvm.org/docs/ClangFormat.html) on llvm.org. +Output from clang-format varies by clang-format version, for best results your +version should match the one used on Jenkins. You can find the clang-format +version by reading the comment in the `.clang-format` file linked above. Before pushing changes for review you can format your code with: @@ -336,7 +493,116 @@ Before pushing changes for review you can format your code with: Check the .clang-format file for the version used to generate it if there is any difference between your local formatting and the review system. -See also: http://clang.llvm.org/docs/ClangFormat.html +Some Git installations have clang-format integration. Here are some examples: + +~~~ + # Apply clang-format to all staged changes: + $ git clang-format + + # Clang format all staged and unstaged changes: + $ git clang-format -f + + # Clang format all staged and unstaged changes interactively: + $ git clang-format -f -p +~~~ + +## Submitting patches + +We manage the submission of patches using the +[Gerrit](https://www.gerritcodereview.com/) code review tool. 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. + +### Login cookie + +Browse to [AOMedia Git index](https://aomedia.googlesource.com/) and login with +your account (Gmail credentials, for example). Next, follow the +`Generate Password` Password link at the top of the page. You’ll be given +instructions for creating a cookie to use with our Git repos. + +### Contributor agreement + +You will be required to execute a +[contributor agreement](http://aomedia.org/license) to ensure that the AOMedia +Project has the right to distribute your changes. + +### Testing your code + +The testing basics are covered in the [testing section](#testing-the-av1-codec) +above. + +In addition to the local tests, many more (e.g. asan, tsan, valgrind) will run +through Jenkins instances upon upload to gerrit. + +### Commit message hook + +Gerrit requires that each submission include a unique Change-Id. You can assign +one manually using git commit --amend, but it’s easier to automate it with the +commit-msg hook provided by Gerrit. + +Copy commit-msg to the `.git/hooks` directory of your local repo. Here's an +example: + +~~~ + $ curl -Lo aom/.git/hooks/commit-msg https://chromium-review.googlesource.com/tools/hooks/commit-msg + + # Next, ensure that the downloaded commit-msg script is executable: + $ chmod u+x aom/.git/hooks/commit-msg +~~~ + +See the Gerrit +[documentation](https://gerrit-review.googlesource.com/Documentation/user-changeid.html) +for more information. + +### Upload your change + +The command line to upload your patch looks like this: + +~~~ + $ git push https://aomedia-review.googlesource.com/aom HEAD:refs/for/master +~~~ + +### Incorporating reviewer comments + +If you previously uploaded a change to Gerrit and the Approver has asked for +changes, follow these steps: + +1. Edit the files to make the changes the reviewer has requested. +2. Recommit your edits using the --amend flag, for example: + +~~~ + $ git commit -a --amend +~~~ + +3. Use the same git push command as above to upload to Gerrit again for another + review cycle. + +In general, you should not rebase your changes when doing updates in response to +review. Doing so can make it harder to follow the evolution of your change in +the diff view. + +### Submitting your change + +Once your change has been Approved and Verified, you can “submit” it through the +Gerrit UI. This will usually automatically rebase your change onto the branch +specified. + +Sometimes this can’t be done automatically. If you run into this problem, you +must rebase your changes manually: + +~~~ + $ git fetch + $ git rebase origin/branchname +~~~ + +If there are any conflicts, resolve them as you normally would with Git. When +you’re done, reupload your change. + +### Viewing the status of uploaded changes + +To check the status of a change that you uploaded, open +[Gerrit](https://aomedia-review.googlesource.com/), sign in, and click My > +Changes. ## Support |