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#codehealth

PiperOrigin-RevId: 370048160
2021-04-26 17:48:23 +01:00
..
2021-04-26 17:48:23 +01:00
2020-09-16 16:36:59 +01:00
2017-01-13 17:27:25 +00:00

ExoPlayer FFmpeg extension

The FFmpeg extension provides FfmpegAudioRenderer, which uses FFmpeg for decoding and can render audio encoded in a variety of formats.

License note

Please note that whilst the code in this repository is licensed under Apache 2.0, using this extension also requires building and including one or more external libraries as described below. These are licensed separately.

Build instructions (Linux, macOS)

To use this extension you need to clone the ExoPlayer repository and depend on its modules locally. Instructions for doing this can be found in ExoPlayer's top level README. The extension is not provided via Google's Maven repository (see #2781 for more information).

In addition, it's necessary to manually build the FFmpeg library, so that gradle can bundle the FFmpeg binaries in the APK:

  • Set the following shell variable:
cd "<path to exoplayer checkout>"
EXOPLAYER_ROOT="$(pwd)"
FFMPEG_EXT_PATH="${EXOPLAYER_ROOT}/extensions/ffmpeg/src/main"
  • Download the Android NDK and set its location in a shell variable. This build configuration has been tested on NDK r21.
NDK_PATH="<path to Android NDK>"
  • Set the host platform (use "darwin-x86_64" for Mac OS X):
HOST_PLATFORM="linux-x86_64"
  • Fetch FFmpeg and checkout an appropriate branch. We cannot guarantee compatibility with all versions of FFmpeg. We currently recommend version 4.2:
cd "<preferred location for ffmpeg>" && \
git clone git://source.ffmpeg.org/ffmpeg && \
cd ffmpeg && \
git checkout release/4.2 && \
FFMPEG_PATH="$(pwd)"
  • Configure the decoders to include. See the Supported formats page for details of the available decoders, and which formats they support.
ENABLED_DECODERS=(vorbis opus flac)
  • Add a link to the FFmpeg source code in the FFmpeg extension jni directory.
cd "${FFMPEG_EXT_PATH}/jni" && \
ln -s "$FFMPEG_PATH" ffmpeg
  • Execute build_ffmpeg.sh to build FFmpeg for armeabi-v7a, arm64-v8a, x86 and x86_64. The script can be edited if you need to build for different architectures:
cd "${FFMPEG_EXT_PATH}/jni" && \
./build_ffmpeg.sh \
  "${FFMPEG_EXT_PATH}" "${NDK_PATH}" "${HOST_PLATFORM}" "${ENABLED_DECODERS[@]}"

Build instructions (Windows)

We do not provide support for building this extension on Windows, however it should be possible to follow the Linux instructions in Windows PowerShell.

Using the extension

Once you've followed the instructions above to check out, build and depend on the extension, the next step is to tell ExoPlayer to use FfmpegAudioRenderer. How you do this depends on which player API you're using:

  • If you're passing a DefaultRenderersFactory to SimpleExoPlayer.Builder, you can enable using the extension by setting the extensionRendererMode parameter of the DefaultRenderersFactory constructor to EXTENSION_RENDERER_MODE_ON. This will use FfmpegAudioRenderer for playback if MediaCodecAudioRenderer doesn't support the input format. Pass EXTENSION_RENDERER_MODE_PREFER to give FfmpegAudioRenderer priority over MediaCodecAudioRenderer.
  • If you've subclassed DefaultRenderersFactory, add an FfmpegAudioRenderer to the output list in buildAudioRenderers. ExoPlayer will use the first Renderer in the list that supports the input media format.
  • If you've implemented your own RenderersFactory, return an FfmpegAudioRenderer instance from createRenderers. ExoPlayer will use the first Renderer in the returned array that supports the input media format.
  • If you're using ExoPlayer.Builder, pass an FfmpegAudioRenderer in the array of Renderers. ExoPlayer will use the first Renderer in the list that supports the input media format.

Note: These instructions assume you're using DefaultTrackSelector. If you have a custom track selector the choice of Renderer is up to your implementation, so you need to make sure you are passing an FfmpegAudioRenderer to the player, then implement your own logic to use the renderer for a given track.

Using the extension in the demo application

To try out playback using the extension in the demo application, see enabling extension decoders.