对libstagefright硬件解码的FFmpeg支持

Question

大家：我是FFMPEG的新手。最近我正在做一个项目，把ffmpeg移植到android设备上。在开始的时候，我按照网上的一些指南，以一种非常正常的方式将ffmpeg编译成共享库（.so文件），加载到我的android应用程序中。它工作得很好。

现在我想让ffmpeg使用libstagefright来完成硬件解码。问题是，我可以编译.so库，但当我启动应用程序并加载这些.so库时，总是会出现java.lang.UnsatisfiedLinkError：无法加载库:reloc_library[1314]:114无法定位'_zn7Android11MediabufferC1EJ'

我在那里呆了几天。之前有没有人遇到过类似的问题？如果有人能给我一些关于这个错误的提示，那就太好了。

我的步骤：1。将FFMPEG-2.1.4源代码编译为.so共享库。我使用了build_libstagefright脚本来完成此操作，并根据Internet上的一些指南进行了一些修改。

#!/bin/bash
#export NDK=/home/mingzhang/android/android-ndk-r9c
export NDK=/home/mingzhang/android/android-ndk-r7
if [ "$NDK" = "" ]; then
    echo NDK variable not set, assuming ${HOME}/android-ndk
    export NDK=${HOME}/android-ndk
fi

echo "Fetching Android system headers"
git clone --depth=1 --branch gingerbread-release git://github.com/CyanogenMod/android_frameworks_base.git ../android-source/frameworks/base
git clone --depth=1 --branch gingerbread-release git://github.com/CyanogenMod/android_frameworks_av.git ../android-source/frameworks/av
git clone --depth=1 --branch gingerbread-release git://github.com/CyanogenMod/android_frameworks_native.git ../android-source/frameworks/native
git clone --depth=1 --branch gingerbread-release git://github.com/CyanogenMod/android_hardware_libhardware.git ../android-source/hardware/libhardware
git clone --depth=1 --branch gingerbread-release git://github.com/CyanogenMod/android_system_core.git ../android-source/system/core

echo "Fetching Android libraries for linking"
# Libraries from any froyo/gingerbread device/emulator should work
# fine, since the symbols used should be available on most of them.
#if [ ! -d "../android-libs" ]; then
#    if [ ! -f "../update-cm-7.0.3-N1-signed.zip" ]; then
#        wget http://download.cyanogenmod.com/get/update-cm-7.0.3-N1-signed.zip -P../
#    fi
#    unzip ../update-cm-7.0.3-N1-signed.zip system/lib/* -d../
#    mv ../system/lib ../android-libs
#    rmdir ../system
#fi

SYSROOT=$NDK/platforms/android-9/arch-arm
# Expand the prebuilt/* path into the correct one
#TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86_64
TOOLCHAIN=/home/mingzhang/android/android-ndk-r7/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86
export PATH=$TOOLCHAIN/bin:$PATH
ANDROID_SOURCE=../android-source
ANDROID_LIBS=../android-libs
ABI="armeabi-v7a"
CC=$TOOLCHAIN/bin/arm-linux-androideabi-gcc
#CC=$TOOLCHAIN/bin/arm-eabi-gcc-4.4.3
NM=$TOOLCHAIN/bin/arm-linux-androideabi-nm
#NM=$TOOLCHAIN/bin/arm-eabi-nm

rm -rf ../build/stagefright
mkdir -p ../build/stagefright

ADDI_CFLAGS="-marm"
DEST=../build/stagefright
DEST="$DEST/$ABI"

FLAGS="--target-os=linux --arch=arm --cpu=armv7-a --cross-prefix=arm-linux-androideabi- --cc=$CC --nm=$NM"
#FLAGS="--target-os=linux --arch=arm --cpu=armv7-a --cross-prefix=arm-eabi- --cc=$CC --nm=$NM"
FLAGS="$FLAGS --sysroot=$SYSROOT"
#FLAGS="$FLAGS --disable-avdevice --disable-decoder=h264 --disable-decoder=h264_vdpau --enable-libstagefright-h264"
FLAGS="$FLAGS --enable-shared --disable-demuxers --disable-muxers --disable-parsers --disable-avdevice --disable-filters --disable-programs --disable-encoders --disable-decoders --disable-decoder=h264 --disable-decoder=h264_vdpau --enable-decoder=libstagefright_h264 --enable-libstagefright-h264 \
    --enable-asm \
    --enable-neon \
    --enable-cross-compile \
    --enable-gpl \
    --disable-static \
    --enable-memalign-hack"

EXTRA_CFLAGS="-I$DEST/include"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$ANDROID_SOURCE/frameworks/native/include"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$ANDROID_SOURCE/frameworks/native/include/media/openmax"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$ANDROID_SOURCE/frameworks/av/include"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$ANDROID_SOURCE/frameworks/base/include -I$ANDROID_SOURCE/system/core/include"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$ANDROID_SOURCE/hardware/libhardware/include"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$ANDROID_SOURCE/frameworks/base/media/libstagefright"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$ANDROID_SOURCE/frameworks/base/include/media/stagefright/openmax"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$NDK/sources/cxx-stl/gnu-libstdc++/4.6/include -I$NDK/sources/cxx-stl/gnu-libstdc++/4.6/libs/$ABI/include"
EXTRA_CFLAGS="$EXTRA_CFLAGS -I$NDK/sources/cxx-stl/stlport/stlport"
EXTRA_CFLAGS="$EXTRA_CFLAGS -march=armv7-a -mfloat-abi=softfp -mfpu=neon -marm -mtune=cortex-a8"
EXTRA_CFLAGS="$EXTRA_CFLAGS -O3 -fpic -DANDROID -DHAVE_SYS_UIO_H=1 -D_STLP_USE_NEWALLOC"

EXTRA_LDFLAGS="-Wl,--fix-cortex-a8 -L$ANDROID_LIBS -Wl,-rpath-link,$ANDROID_LIBS -L$NDK/sources/cxx-stl/gnu-libstdc++/4.6/libs/$ABI -static-libstdc++"
EXTRA_CXXFLAGS="-Wno-multichar -fno-exceptions -fno-rtti"
FLAGS="$FLAGS --prefix=$DEST"

mkdir -p $DEST

echo $FLAGS --extra-cflags="$EXTRA_CFLAGS" --extra-ldflags="$EXTRA_LDFLAGS" --extra-cxxflags="$EXTRA_CXXFLAGS" > $DEST/info.txt
./configure $FLAGS --extra-cflags="$EXTRA_CFLAGS" --extra-ldflags="$EXTRA_LDFLAGS" --extra-cxxflags="$EXTRA_CXXFLAGS" | tee $DEST/configuration.txt
[ $PIPESTATUS == 0 ] || exit 1
make clean
#make -j4 || exit 1
#make -j4
make install || exit 1

将编译好的include和lib目录复制到我的android-ndk-r7/sources/ffmpeg-2.1.4/android/arm目录。这个目录下的android.mk文件是。

local_path:=$（调用my-dir）

include$(CLEAR_VARS)local_module:=libavcodec local_src_files:=lib/libavcodec-55。so local_export_c_include:=$(LOCAL_PATH)/include include$(PREBUILT_SHARED_LIBRARY)

include$(CLEAR_VARS)local_module:=libavformat local_src_files:=lib/libavformat-55。so local_export_c_include:=$(LOCAL_PATH)/include include$(PREBUILT_SHARED_LIBRARY)

include$(CLEAR_VARS)local_module:=libswscale local_src_files:=lib/libswscale-2.so local_export_c_include:=$(LOCAL_PATH)/include include$(PREBUILT_SHARED_LIBRARY)

include$(CLEAR_VARS)local_module:=libavutil local_src_files:=lib/libavutil-52.so LOCAL_EXPORT_C_INCLUDES:=$(LOCAL_PATH)/include include$(PREBUILT_SHARED_LIBRARY)

include$(CLEAR_VARS)local_module:=libavfilter local_src_files:=lib/libavfilter-3。so local_export_c_include:=$(LOCAL_PATH)/include include$(PREBUILT_SHARED_LIBRARY)

include$(CLEAR_VARS)local_module:=libwsresample local_src_files:=lib/libswresample-0。so LOCAL_EXPORT_C_INCLUDES:=$(LOCAL_PATH)/include include$(PREBUILT_SHARED_LIBRARY)

在我的android应用程序的jni目录下，android.mk是。

LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)

LOCAL_MODULE    := libripple
#LOCAL_CFLAGS    := -Werror
LOCAL_SRC_FILES := entrypoint.cpp scene.cpp
LOCAL_LDLIBS    := -llog -lGLESv2 -lm

include $(BUILD_SHARED_LIBRARY)

include $(CLEAR_VARS)

LOCAL_MODULE    := myfflib
LOCAL_SRC_FILES := fflib.c
LOCAL_LDLIBS := -L/home/mingzhang/ffmpeg_android/android-libs -llog -ljnigraphics -lz -landroid -ldl -lm -llog -lgcc -lc -lstagefright -lmedia -lutils -lbinder #-lstdc++
LOCAL_SHARED_LIBRARIES := libavformat libavcodec libswscale libavutil libutils libstagefright libbinder libmedia libstdc++-6

include $(BUILD_SHARED_LIBRARY)
$(call import-module,ffmpeg-2.1.4/android/arm)

而application.mk是：

APP_ABI=armeabi-v7a
#APP_STL=gnustl_static
APP_STL=stlport_static

我不确定你还需要什么材料，如果有什么东西缺失了，请让我知道，我会上传的。非常感谢你们！！！

Answer 1

FFmpeg已删除对https://github.com/FFmpeg/FFmpeg/commit/72673AD7EAE2D4F685F3C0A895558502BFE07C8E的libstagefright的支持（包含在N3.0中）。提交消息：

avcodec: Remove libstagefright

It serves absolutely no purpose other than to confuse potentional
Android developers about how to use hardware acceleration properly
on the the platform. The stagefright "API" is not public, and the
MediaCodec API is the proper way to do this.

Furthermore, stagefright support in avcodec needs a series of
magic incantations and version-specific stuff, such that
using it actually provides downsides compared just using the actual
Android frameworks properly, in that it is a lot more work and confusion
to get it even running. It also leads to a lot of misinformation, like
these sorts of comments (in [1]) that are absolutely incorrect.

[1] http://stackoverflow.com/a/29362353/3115956

所以也许再也不可能了。

使用amediacodec和OpenMax可能会有更好的机会。