Android NDK和FFMPEG构建

Question

I'm trying to build FFMPEG library for my android application using the NDK. I have downloaded the source code from it's website and I think I build it (it's my first try working with NDK and ffmpeg). I have created a build.sh file which I'm using to execute it from command line on Mac OS X. But I have a few questions...

First things is as I know I need Android.mk file so I can use the builded library in my application,but I don't know how to do that for reasons which I told you above. After I run my build.sh I get android folder with a few folders and some libraries. So my first question is, how can I build the Android.mk file which I need...and maybe if someone can explain me why I need it.

My second question is I need some libraries from ffmpeg to be able to use them from my app, but after the build i can't see them in my source tree. I know that I have to enable them in my build.sh and I think I did,but I can't see them. So any kind of information about my build file will be helpful for me to understand how to configure it. Here is how it looks like :

    #!/bin/bash
######################################################
# Usage:
# put this script in top of FFmpeg source tree
# ./build_android
# It generates binary for following architectures:
# ARMv6 
# ARMv6+VFP 
# ARMv7+VFPv3-d16 (Tegra2) 
# ARMv7+Neon (Cortex-A8)
# Customizing:
# 1. Feel free to change ./configure parameters for more features
# 2. To adapt other ARM variants
# set $CPU and $OPTIMIZE_CFLAGS 
# call build_one
######################################################
NDK=~/Desktop/android-ndk-r5b
PLATFORM=$NDK/platforms/android-8/arch-arm/
PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/darwin-x86
function build_one
{
./configure \
    --target-os=darwin \
    --prefix=$PREFIX \
    --enable-cross-compile \
    --extra-libs="-lgcc" \
    --arch=arm \
    --cc=$PREBUILT/bin/arm-linux-androideabi-gcc \
    --cross-prefix=$PREBUILT/bin/arm-linux-androideabi- \
    --nm=$PREBUILT/bin/arm-linux-androideabi-nm \
    --sysroot=$PLATFORM \
    --extra-cflags=" -O3 -fpic -DANDROID -DHAVE_SYS_UIO_H=1 -Dipv6mr_interface=ipv6mr_ifindex -fasm -Wno-psabi -fno-short-enums -fno-strict-aliasing -finline-limit=300 $OPTIMIZE_CFLAGS " \
    --disable-doc \
    --disable-ffmpeg \
    --disable-ffplay \
    --disable-ffserver \
    --disable-ffprobe \
    --extra-ldflags="-Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib -lc -lm -ldl -llog" \
    --enable-zlib \
    --enable-version3 \
    --enable-nonfree \
    --enable-libmp3lame \
    --enable-libspeex \
    --enable-libtheora \
    --enable-libfaac \
    --enable-libvorbis \
    --enable-libaacplus \
    --prefix=$DIST_DIR \
    $ADDITIONAL_CONFIGURE_FLAG

make clean
make  -j4 install
$PREBUILT/bin/arm-linux-androideabi-ar d libavcodec/libavcodec.a inverse.o
$PREBUILT/bin/arm-linux-androideabi-ld -rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib  -soname libffmpeg.so -shared -nostdlib  -z,noexecstack -Bsymbolic --whole-archive --no-undefined -o $PREFIX/libffmpeg.so libavcodec/libavcodec.a libavformat/libavformat.a libavutil/libavutil.a libswscale/libswscale.a -lc -lm -lz -ldl -llog  --warn-once  --dynamic-linker=/system/bin/linker $PREBUILT/lib/gcc/arm-linux-androideabi/4.4.3/libgcc.a
}

#arm v6
#CPU=armv6
#OPTIMIZE_CFLAGS="-marm -march=$CPU"
#PREFIX=./android/$CPU 
#ADDITIONAL_CONFIGURE_FLAG=
#build_one

#arm v7vfpv3
CPU=armv7-a
OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfpv3-d16 -marm -march=$CPU "
PREFIX=./android/$CPU
ADDITIONAL_CONFIGURE_FLAG=
build_one

#arm v7vfp
#CPU=armv7-a
#OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfp -marm -march=$CPU "
#PREFIX=./android/$CPU-vfp
#ADDITIONAL_CONFIGURE_FLAG=
#build_one

#arm v7n
#CPU=armv7-a
#OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=neon -marm -march=$CPU -mtune=cortex-a8"
#PREFIX=./android/$CPU 
#ADDITIONAL_CONFIGURE_FLAG=--enable-neon
#build_one

#arm v6+vfp
#CPU=armv6
#OPTIMIZE_CFLAGS="-DCMP_HAVE_VFP -mfloat-abi=softfp -mfpu=vfp -marm -march=$CPU"
#PREFIX=./android/${CPU}_vfp 
#ADDITIONAL_CONFIGURE_FLAG=
#build_one

Thanks for any kind of useful information/suggestions/examples and etc.

Answer 1

I made a tutorial on how to build ffmpeg and x264 for android : zip with build of ffmpeg with x264

You can also download the zip file containing the files you need to make an application on android .

Answer 2

If you want more detailed instruction of how to build ffmpeg and how to use it to build Android apps, please refer to the book Android NDK cookbook: http://www.packtpub.com/android-native-development-kit-cookbook/book

The Bonus Chapter 1 is dedicated to multimedia app development with Android NDK and ffmpeg, and it is available for free at http://www.packtpub.com/sites/default/files/downloads/Developing_Multimedia_Applications_with_NDK.pdf

Answer 3

First of all, you should read the documentation for Android NDK and check out some sample apps. You'll find these details in android_NDK_home/docs and android_NDK_home/samples (where android_NDK_home is the folder name for your android NDK).

Also, check this link on stackoverflow: Using FFmpeg with Android-NDK

For a stept by step tutorial, this is a pretty good one: http://www.roman10.net/how-to-build-ffmpeg-for-android/

Also, you'll have to install/configure some elements on your Eclipse to enable support for developing applications that are built with the NDK: http://mhandroid.wordpress.com/2011/01/23/using-eclipse-for-android-cc-development/ http://wiki.eclipse.org/Sequoyah/ndk_checklist

And a pretty good project that uses the ffmpeg library: https://github.com/havlenapetr/FFMpeg

Answer 4

ffmpeg uses autoconf as its build system. As of the time of this writing, no one has yet put together a Gradle build package for ffmpeg on Android. As far as I can tell, Gradle doesn't yet support autoconf, which makes it pretty difficult to do so

That said, after trying several of the tutorials that were out there, as well as some of the pre-built packages, we decided to roll our own Android build script wrapper for ffmpeg that includes support for OpenSSL and librtmp .

You can find it here: https://github.com/cine-io/android-ffmpeg-with-rtmp

Prerequisite: The Android NDK must be installed

Instructions:

$ git clone git@github.com:cine-io/android-ffmpeg-with-rtmp.git
$ cd android-ffmpeg-with-rtmp
$ ./build.sh

When the script is finished, the required shared libraries and ffmpeg executable will be put into the build/dist directory. You can include them in your project just like any other native binary.

Answer 5

To build ffmpeg executable, I use the following Android.mk :

SYSROOT-armeabi-v7a      := $(NDK_ROOT)/platforms/android-9/arch-arm/
SYSROOT-arm64-v8a := $(NDK_ROOT)/platforms/android-21/arch-arm64/
SYSROOT-x86      := $(NDK_ROOT)/platforms/android-9/arch-x86/
SYSROOT := $(SYSROOT-$(TARGET_ARCH_ABI))

TOOLCHAIN_TARGET_ARCH-armeabi-v7a := arm
TOOLCHAIN_TARGET_ARCH-arm64-v8a := aarch64
TOOLCHAIN_TARGET_ARCH-x86 := i686
TOOLCHAIN_TARGET_ARCH := $(TOOLCHAIN_TARGET_ARCH-$(TARGET_ARCH_ABI))

TOOLCHAIN_TARGET_ABI-armeabi-v7a := androideabi
TOOLCHAIN_TARGET_ABI-arm64-v8a := android
TOOLCHAIN_TARGET_ABI-x86 := android
TOOLCHAIN_TARGET_ABI := $(TOOLCHAIN_TARGET_ABI-$(TARGET_ARCH_ABI))

TOOLCHAIN_TRIPLET := $(TOOLCHAIN_TARGET_ARCH)-linux-$(TOOLCHAIN_TARGET_ABI)-

TOOLCHAIN_NAME-$(TARGET_ARCH_ABI) := $(TOOLCHAIN_TRIPLET)$(TOOLCHAIN_VERSION)
TOOLCHAIN_NAME-x86 := x86-$(TOOLCHAIN_VERSION)
TOOLCHAIN_NAME := $(TOOLCHAIN_NAME-$(TARGET_ARCH_ABI))

TOOLCHAIN_VERSION_PREFIX := $(TOOLCHAIN_TRIPLET)$(TOOLCHAIN_VERSION)

ARCH_ARM_MODE-armeabi := arm
ARCH_ARM_MODE-armeabi-v7a := thumb
ARCH_ARM_MODE-arm64-v8a := thumb
ARCH_ARM_MODE := $(ARCH_ARM_MODE-$(TARGET_ARCH_ABI))

include $(CLEAR_VARS)
LOCAL_ARM_MODE   := $(ARCH_ARM_MODE)

FFMPEG_PATH      := $(BUILD_DIRECTORY)/ffmpeg

LOCAL_CFLAGS-armeabi-v7a := -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=softfp
LOCAL_CFLAGS-x86 := -m32
LOCAL_CFLAGS-arm64-v8a := -march=armv8-a+simd+fp

LOCAL_CFLAGS := $(LOCAL_CFLAGS-$(TARGET_ARCH_ABI))

LOCAL_LDFLAGS-x86 := -m32 -Wl,-eh-frame-hdr -Wl,-m,elf_i386 -Wl,-z,noexecstack -Wl,-z,relro -Wl,-z,now

LOCAL_LDFLAGS := $(LOCAL_LDFLAGS-$(TARGET_ARCH_ABI))

LOCAL_CFLAGS += -fPIE
LOCAL_LDFLAGS += -fPIE -pie

FFMPEG_CONFIG_OPTS := 

FFMPEG_CONFIG_OPTS += --target-os=linux
FFMPEG_CONFIG_OPTS-$(TARGET_ARCH_ABI) := --cross-prefix=$(TOOLCHAIN_PREFIX)
FFMPEG_CONFIG_OPTS-$(TARGET_ARCH_ABI) += --enable-cross-compile
FFMPEG_CONFIG_OPTS-$(TARGET_ARCH_ABI) += --sysroot=$(SYSROOT)
FFMPEG_CONFIG_OPTS += $(FFMPEG_CONFIG_OPTS-$(TARGET_ARCH_ABI))

## disable
FFMPEG_CONFIG_OPTS += --disable-doc
FFMPEG_CONFIG_OPTS += --disable-shared
FFMPEG_CONFIG_OPTS += --disable-avdevice
FFMPEG_CONFIG_OPTS += --disable-postproc
FFMPEG_CONFIG_OPTS += --disable-network
FFMPEG_CONFIG_OPTS += --disable-iconv
FFMPEG_CONFIG_OPTS += --disable-zlib
FFMPEG_CONFIG_OPTS += --disable-ffplay
FFMPEG_CONFIG_OPTS += --disable-ffprobe
FFMPEG_CONFIG_OPTS += --disable-ffserver
FFMPEG_CONFIG_OPTS += --disable-swscale-alpha
## enable
FFMPEG_CONFIG_OPTS += --enable-pthreads
FFMPEG_CONFIG_OPTS += --enable-small

FFMPEG_CONFIG_OPTS += --extra-cflags="$(LOCAL_CFLAGS)"
FFMPEG_CONFIG_OPTS += --extra-cxxflags="$(LOCAL_CXXFLAGS)"
FFMPEG_CONFIG_OPTS += --extra-ldflags="$(LOCAL_LDFLAGS)"

FFMPEG_CONFIG_OPTS += --enable-runtime-cpudetect

ARMBITS-$(TARGET_ARCH_ABI) :=
ARMBITS-arm64-v8a := 64
ARMBITS := $(ARMBITS-$(TARGET_ARCH_ABI))

FFMPEG_CONFIG_OPTS-$(TARGET_ARCH_ABI) :=

FFMPEG_CONFIG_OPTS-armeabi := --enable-armv5te
FFMPEG_CONFIG_OPTS-armeabi += --enable-inline-asm
FFMPEG_CONFIG_OPTS-armeabi += --arch=arm$(ARMBITS)

FFMPEG_CONFIG_OPTS-armeabi-v7a := $(FFMPEG_CONFIG_OPTS-armeabi)
FFMPEG_CONFIG_OPTS-armeabi-v7a += --enable-armv6
FFMPEG_CONFIG_OPTS-armeabi-v7a += --enable-armv6t2
FFMPEG_CONFIG_OPTS-armeabi-v7a += --enable-vfp
FFMPEG_CONFIG_OPTS-armeabi-v7a += --enable-neon
FFMPEG_CONFIG_OPTS-armeabi-v7a += --enable-thumb
FFMPEG_CONFIG_OPTS-armeabi-v7a += --enable-fast-unaligned

FFMPEG_CONFIG_OPTS-arm64-v8a := $(FFMPEG_CONFIG_OPTS-armeabi-v7a)

FFMPEG_CONFIG_OPTS-x86 := --enable-yasm
FFMPEG_CONFIG_OPTS-x86 += --arch=x86

FFMPEG_CONFIG_OPTS += $(FFMPEG_CONFIG_OPTS-$(TARGET_ARCH_ABI))

LOCAL_MODULE := ffmpeg
LOCAL_SRC_FILES := $(abspath $(TARGET_OBJS))/ffmpeg/lib...ffmpeg...so # see http://stackoverflow.com/a/17384650/192373

clean: $(TARGET_OBJS)/ffmpeg/clean

$(TARGET_OBJS)/ffmpeg/clean: PRIVATE_ABI := $(FFMPEG_TARGET_ABI)
$(TARGET_OBJS)/ffmpeg/clean:
    $(call host-echo-build-step,$(PRIVATE_ABI),Clean) "ffmpeg [$(PRIVATE_ABI)]"
    $(hide) $(call host-rmdir,$(@D))

$(shell $(call host-mkdir,$(dir $(LOCAL_SRC_FILES))))
$(shell $(HOST_ECHO) >$(LOCAL_SRC_FILES))
.PHONY: $(LOCAL_SRC_FILES)
$(LOCAL_SRC_FILES): $(TARGET_OBJS)/ffmpeg/ffmpeg
    $(hide) $(call host-mv,$<,$@)

include $(PREBUILT_SHARED_LIBRARY)

$(TARGET_OBJS)/ffmpeg/Makefile: FFMPEG_CONFIG_OPTS := $(FFMPEG_CONFIG_OPTS)
$(TARGET_OBJS)/ffmpeg/Makefile:
    $(hide) $(call host-mkdir,$(@D))
    $(hide) cd $(@D) && $(abspath $(FFMPEG_PATH))/configure $(FFMPEG_CONFIG_OPTS)

$(TARGET_OBJS)/ffmpeg/ffmpeg: FFMPEG_CONFIG_OPTS := using toolchain:$(NDK_ROOT)/toolchains/$(TOOLCHAIN_NAME) compiler:$(TOOLCHAIN_COMPILER) triplet:$(TOOLCHAIN_TRIPLET)
$(TARGET_OBJS)/ffmpeg/ffmpeg: $(TARGET_OBJS)/ffmpeg/Makefile
    @echo $(FFMPEG_CONFIG_OPTS)
    $(hide) $(MAKE) --no-print-directory -C $(@D)