ffmpeg 라이브러리 빌드 #1

 

 

ffmpeg을 사용할 일이 있어 ndk로 빌드환경 구성을 알아보았다. ffmpeg을 언젠가 만져보긴 했는데,

아마도 다이렉트쇼 필터 만들때였던것 같은데.. 이미 까막눈이 되어 있어서, 구글링~

 

 우선 참조할 만한 블로그 들.

 

1. 소스코드 다운로드

ffmpeg : http://www.ffmpeg.org/download.html

 

$ sudo apt-get install git-core

$ git clone git://git.videolan.org/ffmpeg

 

2. 참조 사이트 : static 빌드로 라이브러리를 생성을 위한 작업설명

* 음.. 리눅스용 ndk r5c 에는 툴체인 경로가 포스트의 내용과 차이가 있음.

 

 

http://androidcore.com/android-programming-tutorials/641-how-to-compile-ffmpeg-on-android.html

 

Create a new project, make jni folder, then download and extract ffmpeg, rename ffmpeg folder to ffmpeg.

 

Make a new config.sh in ffmpeg, notice a bout PREBUILT path and PLATFORM:

 

 

#!/bin/bash

PREBUILT=/home/abitno/Android/android-ndk-r4/build/prebuilt/linux-x86/arm-eabi-4.4.0
PLATFORM=/home/abitno/Android/android-ndk-r4/build/platforms/android-8/arch-arm

./configure --target-os=linux \
        --arch=arm \
        --enable-version3 \
        --enable-gpl \
        --enable-nonfree \
        --disable-stripping \
        --disable-ffmpeg \
        --disable-ffplay \
        --disable-ffserver \
        --disable-ffprobe \
        --disable-encoders \
        --disable-muxers \
        --disable-devices \
        --disable-protocols \
        --enable-protocol=file \
        --enable-avfilter \
        --disable-network \
        --disable-mpegaudio-hp \
        --disable-avdevice \
        --enable-cross-compile \
        --cc=$PREBUILT/bin/arm-eabi-gcc \
        --cross-prefix=$PREBUILT/bin/arm-eabi- \
        --nm=$PREBUILT/bin/arm-eabi-nm \
        --extra-cflags="-fPIC -DANDROID" \
        --disable-asm \
        --enable-neon \
        --enable-armv5te \
        --extra-ldflags="-Wl,-T,$PREBUILT/arm-eabi/lib/ldscripts/armelf.x

-Wl,-rpath-link=$PLATFORM/usr/lib

-L$PLATFORM/usr/lib -nostdlib $PREBUILT/lib/gcc/arm-eabi/4.4.0/crtbegin.o

$PREBUILT/lib/gcc/arm-eabi/4.4.0/crtend.o -lc -lm -ldl"

 

 

Then change mode config.sh and run

 

 

chmod +x config.sh
./config.sh

 

 

When config is completed, open config.h, find:

 

#define restrict restrict

 

replace by

 

#define restrict

 

 

Open libavutil/libm.h, remove static keyword in all function declaration.

Open Makefile in libavcodec, libavfilter, libavformat, libavutil, libpostproc and libswscale and remove two lines:

 

 

include $(SUBDIR)../subdir.mak
include $(SUBDIR)../config.mak

 

 

add new av.mk file in ffmpeg folder:

# LOCAL_PATH is one of libavutil, libavcodec, libavformat, or libswscale

#include $(LOCAL_PATH)/../config-$(TARGET_ARCH).mak
include $(LOCAL_PATH)/../config.mak

OBJS :=
OBJS-yes :=
MMX-OBJS-yes :=
include $(LOCAL_PATH)/Makefile

# collect objects
OBJS-$(HAVE_MMX) += $(MMX-OBJS-yes)
OBJS += $(OBJS-yes)

FFNAME := lib$(NAME)
FFLIBS := $(foreach,NAME,$(FFLIBS),lib$(NAME))
FFCFLAGS  = -DHAVE_AV_CONFIG_H -Wno-sign-compare -Wno-switch -Wno-pointer-sign
FFCFLAGS += -DTARGET_CONFIG=\"config-$(TARGET_ARCH).h\"

ALL_S_FILES := $(wildcard $(LOCAL_PATH)/$(TARGET_ARCH)/*.S)
ALL_S_FILES := $(addprefix $(TARGET_ARCH)/, $(notdir $(ALL_S_FILES)))

ifneq ($(ALL_S_FILES),)
ALL_S_OBJS := $(patsubst %.S,%.o,$(ALL_S_FILES))
C_OBJS := $(filter-out $(ALL_S_OBJS),$(OBJS))
S_OBJS := $(filter $(ALL_S_OBJS),$(OBJS))
else
C_OBJS := $(OBJS)
S_OBJS :=
endif

C_FILES := $(patsubst %.o,%.c,$(C_OBJS))
S_FILES := $(patsubst %.o,%.S,$(S_OBJS))

FFFILES := $(sort $(S_FILES)) $(sort $(C_FILES))

 

 

Create Android.mk in jni folder:

 

include $(all-subdir-makefiles)

 

Create Android.mk in ffmpeg folder:

 

 

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_STATIC_LIBRARIES := libavformat libavcodec libavutil libpostproc libswscale
LOCAL_MODULE := ffmpeg
include $(BUILD_SHARED_LIBRARY)
include $(call all-makefiles-under,$(LOCAL_PATH))

 

 

libavformat/Android.mk

 

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
include $(LOCAL_PATH)/../av.mk
LOCAL_SRC_FILES := $(FFFILES)
LOCAL_C_INCLUDES :=                \
        $(LOCAL_PATH)                \
        $(LOCAL_PATH)/..
LOCAL_CFLAGS += $(FFCFLAGS)
LOCAL_CFLAGS += -include "string.h" -Dipv6mr_interface=ipv6mr_ifindex
LOCAL_LDLIBS := -lz
LOCAL_STATIC_LIBRARIES := $(FFLIBS)
LOCAL_MODULE := $(FFNAME)
include $(BUILD_STATIC_LIBRARY)

 

 

libavcodec/Android.mk

 

 

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
include $(LOCAL_PATH)/../av.mk
LOCAL_SRC_FILES := $(FFFILES)
LOCAL_C_INCLUDES :=                \
        $(LOCAL_PATH)                \
        $(LOCAL_PATH)/..
LOCAL_CFLAGS += $(FFCFLAGS)
LOCAL_LDLIBS := -lz
LOCAL_STATIC_LIBRARIES := $(FFLIBS)
LOCAL_MODULE := $(FFNAME)
include $(BUILD_STATIC_LIBRARY)

 

 

libavfilter, libavutil, libpostproc and libswscale / Android.mk

 

 

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
include $(LOCAL_PATH)/../av.mk
LOCAL_SRC_FILES := $(FFFILES)
LOCAL_C_INCLUDES :=                \
        $(LOCAL_PATH)                \
        $(LOCAL_PATH)/..
LOCAL_CFLAGS += $(FFCFLAGS)
LOCAL_STATIC_LIBRARIES := $(FFLIBS)
LOCAL_MODULE := $(FFNAME)
include $(BUILD_STATIC_LIBRARY)

 

 

 

3. 참조사이트 2 : http://www.cnblogs.com/scottwong/archive/2010/12/17/1909455.html

이곳은 shared 라이브러리.

 ffmpeg 의 confgure 스크립트를 실행시키면 config.h 가 생성되는데, 이를 사용해 빌드할 소스를 적용하는 방법을 사용하고 있다.

 

 

 

4. 기타 참조할만한 사이트

http://bambuser.com/opensource : ffmpeg 소스코드 제공

 

음.. bambuser.com의 소스는 ndk 빌드가 아닌 ndk 툴체인만 이용해서 빌드.

라이브러리단의 변경 없이 배포하고, shared 인 경우는 이 방법이 가장 간편.

 

대강 설치용 스크립트를 살펴보면 아래와 같다.

환경변수 설정

NDK=~/android-ndk-r5c

SYSROOT=$NDK/platforms/android-3/arch-arm

TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86

DEST=../out/ffmpeg/armeabi

export PATH=$TOOLCHAIN/bin:$PATH

 

빌드 옵션 설정

--target-os=linux \

--arch=arm \

--cross-prefix=arm-linux-androideabi- \

--sysroot= $SYSROOT \

--enable-shared \

--disable-symver \

--enable-small \

--optimization-flags=-O2

--disable-everything

--prefix=$DEST

 

플래그

default

--extra-cflags=

--extra-ldflags=

 

armv7a

--extra-cflags="-march=armv7-a -mfloat-abi=softfp"

--extra-ldflags=

 

neon

--extra-cflags="-march=armv7-a -mfloat-abi=softfp -mfpu=neon"

--extra-ldflags="-Wl,--fix-cortex-a8"

 

 

FFMPEG configure

cd ffmpeg

./configure 빌드옵션 --extra-cflags= --extra-ldflags=

make clean

make -j4

make install