Media3 ExoPlayer扩展FFmpeg音视频解码

1.下载Exoplayer源码

git clone https://github.com/androidx/media

参考 官方教程media/libraries/decoder_ffmpeg路径下的README.md

找到ffmpeg编译脚本：media/libraries/decoder_ffmpeg/src/main/jni路径下的build_ffmpeg.sh

//build_ffmpeg.sh
FFMPEG_MODULE_PATH="$1"
echo "FFMPEG_MODULE_PATH is ${FFMPEG_MODULE_PATH}"
NDK_PATH="$2"
echo "NDK path is ${NDK_PATH}"
HOST_PLATFORM="$3"
echo "Host platform is ${HOST_PLATFORM}"
ANDROID_ABI="$4"
echo "ANDROID_ABI is ${ANDROID_ABI}"
ENABLED_DECODERS=("${@:5}")
echo "Enabled decoders are ${ENABLED_DECODERS[@]}"

2.环境配置

按照要求分别配置：FFMPEG_MODULE_PATH NDK_PATH HOST_PLATFORM ANDROID_ABI ENABLED_DECODERS

附官网NDK下载地址：developer.android.google.cn/ndk/downloa…

音频采样格式与相应 FFmpeg 解码器名称之间的映射：

developer.android.google.cn/media/media…

#1.FFMPEG_MODULE_PATH：ExoPlayer中FFmpeg模块路径
cd media
FFMPEG_MODULE_PATH="$(pwd)/libraries/decoder_ffmpeg/src/main"
#2.NDK_PATH：NDK路径
cd android-ndk-r22b
NDK_PATH="$(pwd)"
#3.HOST_PLATFORM：编译平台，Mac为darwin-x86_64，Linux为linux-x86_64
HOST_PLATFORM="linux-x86_64"
#4.ANDROID_ABI：最小支持Android版本（如果 ANDROID_ABI 小于 21，则可以使用 NDK r23c）
ANDROID_ABI=21
#5.ENABLED_DECODERS：解码器格式
ENABLED_DECODERS=(aac ac3 mp3 flac h264 hevc)

3.下载FFmpeg及编译

git clone git://source.ffmpeg.org/ffmpeg
cd ffmpeg
#切到当前推荐的FFmpeg版本6.0
git checkout release/6.0
FFMPEG_PATH="$(pwd)"
#关联FFmpeg源码
cd "${FFMPEG_MODULE_PATH}/jni"
ln -s "$FFMPEG_PATH" ffmpeg
#编译FFmpeg
./build_ffmpeg.sh \
  "${FFMPEG_MODULE_PATH}" "${NDK_PATH}" "${HOST_PLATFORM}" "${ANDROID_ABI}" "${ENABLED_DECODERS[@]}"

编译成功会在ffmpeg生成android-libs目录，里面包含.a文件

4.下载libyuv及编译

libyuv编译脚本build_yuv.sh

#!/bin/bash
set -eu

FFMPEG_MODULE_PATH="$1"
echo "FFMPEG_MODULE_PATH is ${FFMPEG_MODULE_PATH}"
NDK_PATH="$2"
echo "NDK path is ${NDK_PATH}"
ANDROID_ABI="$3"
echo "ANDROID_ABI is ${ANDROID_ABI}"

ABI_LIST="armeabi-v7a arm64-v8a x86 x86_64"
echo "ABI List is ${ABI_LIST}"

ANDROID_ABI_64BIT="$ANDROID_ABI"
if [[ "$ANDROID_ABI_64BIT" -lt 21 ]]
then
    echo "Using ANDROID_ABI 21 for 64-bit architectures"
    ANDROID_ABI_64BIT=21
fi

cd "${FFMPEG_MODULE_PATH}/jni/libyuv"

for abi in ${ABI_LIST}; do
  rm -rf "build-${abi}"
  mkdir "build-${abi}"
  cd "build-${abi}"

  cmake .. \
    -G "Unix Makefiles" \
    -DCMAKE_TOOLCHAIN_FILE=$NDK_PATH/build/cmake/android.toolchain.cmake -DANDROID_ABI=${abi} -DCMAKE_ANDROID_ARCH_ABI=${abi} \
    -DANDROID_NDK=${NDK_PATH} \
    -DANDROID_PLATFORM=${ANDROID_ABI} \
    -DCMAKE_BUILD_TYPE=Release \
    -DBUILD_SHARED_LIBS=ON \
    -DCMAKE_SYSTEM_NAME=Generic \
    -DCMAKE_ANDROID_STL_TYPE=c++_shared \
    -DCMAKE_SYSTEM_NAME=Android \
    -DCMAKE_THREAD_PREFER_PTHREAD=TRUE \
    -DTHREADS_PREFER_PTHREAD_FLAG=TRUE \
    -DBUILD_STATIC_LIBS=OFF

  cmake --build .
  cd ..
done

for abi in ${ABI_LIST}; do
  mkdir -p "./android-libs/${abi}"
  cp -r "build-${abi}/libyuv.so" "./android-libs/${abi}/libyuv.so"
  echo "build-${abi}/libyuv.so was successfully copied to ./android-libs/${abi}/libyuv.so!"
done

#git clone https://chromium.googlesource.com/libyuv/libyuv
git clone https://gitee.com/bestchangge/libyuv
YUV_PATH="$(pwd)"
cd "${FFMPEG_MODULE_PATH}/jni"
ln -s "$YUV_PATH" libyuv
# cmake需要装一下
sudo apt update
sudo apt install cmake
# 编译libyuv
./build_yuv.sh \
  "${FFMPEG_MODULE_PATH}" "${NDK_PATH}" "${ANDROID_ABI}"

编译成功会在libyuv生成android-libs目录，里面包含.so文件

5.验证

依赖lib-decoder-ffmpeg模块即可，DefaultRenderersFactory中有通过Class.forName去找解码器

DefaultRenderersFactory renderersFactory = new DefaultRenderersFactory(this);
/**
 * EXTENSION_RENDERER_MODE_OFF：禁用扩展渲染器
 * EXTENSION_RENDERER_MODE_ON：启用扩展渲染器，但核心渲染器优先级更高
 * EXTENSION_RENDERER_MODE_PREFER：启用扩展渲染器，且扩展渲染器优先级更高
 */
 //为测试ffmpeg使用的EXTENSION_RENDERER_MODE_PREFER，建议使用EXTENSION_RENDERER_MODE_ON
renderersFactory.setExtensionRendererMode(DefaultRenderersFactory.EXTENSION_RENDERER_MODE_PREFER);
player = new ExoPlayer.Builder(this,renderersFactory).build();

运行可以在Log控制台上看到

//视频解码
videoDecoderInitialized [eventTime=0.66, mediaPos=0.00, window=0, period=0, ffmpegLavc60.3.100-h264]
//音频解码
audioDecoderInitialized [eventTime=0.68, mediaPos=0.00, window=0, period=0, ffmpegLavc60.3.100-aac]