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6a928805d4
Also fixed the javadoc link in devsite and removed javadoc links from decoder extensions as it is not published yet on developer.android.com. #minor-release PiperOrigin-RevId: 520636868
129 lines
5.0 KiB
Markdown
129 lines
5.0 KiB
Markdown
# AV1 decoder module
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The AV1 module provides `Libgav1VideoRenderer`, which uses libgav1 native
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library to decode AV1 videos.
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## License note
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Please note that whilst the code in this repository is licensed under
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[Apache 2.0][], using this module also requires building and including one or
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more external libraries as described below. These are licensed separately.
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[Apache 2.0]: ../../LICENSE
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## Build instructions (Linux, macOS)
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To use the module you need to clone this GitHub project and depend on its
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modules locally. Instructions for doing this can be found in the
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[top level README][].
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In addition, it's necessary to fetch cpu_features library and libgav1 with its
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dependencies as follows:
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* Set the following environment variables:
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```
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cd "<path to project checkout>"
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AV1_MODULE_PATH="$(pwd)/libraries/decoder_av1/src/main"
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```
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* Fetch cpu_features library:
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```
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cd "${AV1_MODULE_PATH}/jni" && \
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git clone https://github.com/google/cpu_features
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```
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* Fetch libgav1:
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```
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cd "${AV1_MODULE_PATH}/jni" && \
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git clone https://chromium.googlesource.com/codecs/libgav1
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```
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* Fetch Abseil:
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```
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cd "${AV1_MODULE_PATH}/jni/libgav1" && \
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git clone https://github.com/abseil/abseil-cpp.git third_party/abseil-cpp
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```
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* [Install CMake][].
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Having followed these steps, gradle will build the module automatically when run
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on the command line or via Android Studio, using [CMake][] and [Ninja][] to
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configure and build libgav1 and the module's [JNI wrapper library][].
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[top level README]: ../../README.md
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[Install CMake]: https://developer.android.com/studio/projects/install-ndk
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[CMake]: https://cmake.org/
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[Ninja]: https://ninja-build.org
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[JNI wrapper library]: src/main/jni/gav1_jni.cc
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## Build instructions (Windows)
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We do not provide support for building this module on Windows, however it should
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be possible to follow the Linux instructions in [Windows PowerShell][].
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[Windows PowerShell]: https://docs.microsoft.com/en-us/powershell/scripting/getting-started/getting-started-with-windows-powershell
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## Using the module with ExoPlayer
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Once you've followed the instructions above to check out, build and depend on
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the module, the next step is to tell ExoPlayer to use `Libgav1VideoRenderer`.
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How you do this depends on which player API you're using:
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* If you're passing a `DefaultRenderersFactory` to `ExoPlayer.Builder`, you
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can enable using the module by setting the `extensionRendererMode` parameter
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of the `DefaultRenderersFactory` constructor to
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`EXTENSION_RENDERER_MODE_ON`. This will use `Libgav1VideoRenderer` for
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playback if `MediaCodecVideoRenderer` doesn't support decoding the input AV1
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stream. Pass `EXTENSION_RENDERER_MODE_PREFER` to give `Libgav1VideoRenderer`
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priority over `MediaCodecVideoRenderer`.
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* If you've subclassed `DefaultRenderersFactory`, add a
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`Libvgav1VideoRenderer` to the output list in `buildVideoRenderers`.
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ExoPlayer will use the first `Renderer` in the list that supports the input
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media format.
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* If you've implemented your own `RenderersFactory`, return a
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`Libgav1VideoRenderer` instance from `createRenderers`. ExoPlayer will use
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the first `Renderer` in the returned array that supports the input media
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format.
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* If you're using `ExoPlayer.Builder`, pass a `Libgav1VideoRenderer` in the
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array of `Renderer`s. ExoPlayer will use the first `Renderer` in the list
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that supports the input media format.
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Note: These instructions assume you're using `DefaultTrackSelector`. If you have
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a custom track selector the choice of `Renderer` is up to your implementation.
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You need to make sure you are passing a `Libgav1VideoRenderer` to the player and
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then you need to implement your own logic to use the renderer for a given track.
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## Rendering options
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There are two possibilities for rendering the output `Libgav1VideoRenderer`
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gets from the libgav1 decoder:
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* GL rendering using GL shader for color space conversion
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* If you are using `ExoPlayer` with `PlayerView`, enable this option by
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setting the `surface_type` of the view to be
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`video_decoder_gl_surface_view`.
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* Otherwise, enable this option by sending `Libgav1VideoRenderer` a
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message of type `Renderer.MSG_SET_VIDEO_OUTPUT` with an instance of
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`VideoDecoderOutputBufferRenderer` as its object.
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`VideoDecoderGLSurfaceView` is the concrete
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`VideoDecoderOutputBufferRenderer` implementation used by `PlayerView`.
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* Native rendering using `ANativeWindow`
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* If you are using `ExoPlayer` with `PlayerView`, this option is enabled
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by default.
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* Otherwise, enable this option by sending `Libgav1VideoRenderer` a
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message of type `Renderer.MSG_SET_VIDEO_OUTPUT` with an instance of
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`SurfaceView` as its object.
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Note: Although the default option uses `ANativeWindow`, based on our testing the
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GL rendering mode has better performance, so should be preferred
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<!-- TODO(b/204738828): Add link to 'troubleshooting using decoding extensions' media3 guide entry when it's published on developer.android.com -->
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<!-- TODO(b/276289331): Add Javadoc link when it's published on developer.android.com -->
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