下面介绍如何将ffmpeg编译成动态库libffmpegjni.so。

在主目录下新建文件夹ayer/jni,将ffmpeg拷贝到jni目录中。在ayer目录下新建Android.mk文件，程序为：

~/ayer/jni/Android.mk
include $(all-subdir-makefiles)

~/ayer/jni/ffmpeg/Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_WHOLE_STATIC_LIBRARIES := libavformat libavcodec libavutil libpostproc libswscale

LOCAL_MODULE := ffmpeg

include $(BUILD_SHARED_LIBRARY)

include $(call all-makefiles-under,$(LOCAL_PATH))

~/ayer/jni/ffmpeg/av.mk

# 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))

~/ayer/jni/ffmpeg/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)

~/ayer/jni/ffmpeg/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)

~/ayer/jni/ffmpeg/libavfilter/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)

~/ayer/jni/ffmpeg/libavutil/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)

~/ayer/jni/ffmpeg/libpostproc/Android.mk