FFmpeg support for libstagefright hardware decoding

问题

everyone: I am new to ffmpeg. Recently I am working on project to port ffmpeg to android device. At the beginning, I compiled ffmpeg to shared libs(.so files) in a very normal way following some guides on Internet, load them into my android app. It works perfectly.

Now I want ffmpeg to use libstagefright to fulfill HW decoding. The problem is, I can compile the .so libs, but when I launch my app and load those .so libs, there is always a java.lang.UnsatisfiedLinkError: Cannot load library: reloc_library[1314]: 114 cannot locate '_ZN7android11MediaBufferC1Ej'

I stuck there for a few days. Does anyone encountered any similar problems before? It would be great if someone can give me some hint about this error.

My steps: 1. Compile ffmpeg-2.1.4 souce code to .so shared libs. I use the build_libstagefright script to do this, and make some modification based on some guides from Internet.

#!/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

Copy the compiled include and lib directories to my android-ndk-r7/sources/ffmpeg-2.1.4/android/arm directory. The Android.mk file under this directory is.

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS) LOCAL_MODULE:= libavcodec LOCAL_SRC_FILES:= lib/libavcodec-55.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS) LOCAL_MODULE:= libavformat LOCAL_SRC_FILES:= lib/libavformat-55.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS) LOCAL_MODULE:= libswscale LOCAL_SRC_FILES:= lib/libswscale-2.so LOCAL_EXPORT_C_INCLUDES := $(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_INCLUDES := $(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)

Under the jni directory of my android app, the Android.mk is.

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)

And the Application.mk is:

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

I am not sure what else materials you need, if anything is missing, please let me know, I will upload it. Thank you guys very much!!!

回答1:

FFmpeg has removed support for libstagefright at https://github.com/FFmpeg/FFmpeg/commit/72673ad7eae2d4f685f3c0a895558502bfe07c8e (included in n3.0). Commit message:

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

so maybe it is not possible anymore.

You may have better chances with AMediaCodec and OpenMAX.

来源：https://stackoverflow.com/questions/25818668/ffmpeg-support-for-libstagefright-hardware-decoding

标签

android

video

android-ndk

ffmpeg

stagefright