.It explains how to cross compile the ffmpeg.Once compiled you will get the standard .so like
#ffmpeg pre-built modules
include $(CLEAR_VARS)
LOCAL_MODULE := myffmpeg1
LOCAL_SRC_FILES := libavcodec.so
include $(PREBUILT_SHARED_LIBRARY)
#ffmpeg pre-built modules
include $(CLEAR_VARS)
LOCAL_MODULE := myffmpeg2
LOCAL_SRC_FILES := libavcore.so
include $(PREBUILT_SHARED_LIBRARY)
#ffmpeg pre-built modules
include $(CLEAR_VARS)
LOCAL_MODULE := myffmpeg3
LOCAL_SRC_FILES := libavfilter.so
include $(PREBUILT_SHARED_LIBRARY)
#ffmpeg pre-built modules
include $(CLEAR_VARS)
LOCAL_MODULE := myffmpeg4
LOCAL_SRC_FILES := libavformat.so
include $(PREBUILT_SHARED_LIBRARY)
#ffmpeg pre-built modules
include $(CLEAR_VARS)
LOCAL_MODULE := myffmpeg5
LOCAL_SRC_FILES := libavutil.so
include $(PREBUILT_SHARED_LIBRARY)
#ffmpeg pre-built modules
include $(CLEAR_VARS)
LOCAL_MODULE := myffmpeg6
LOCAL_SRC_FILES := libswscale.so
include $(PREBUILT_SHARED_LIBRARY)
#ffmpeg pre-built modules
include $(CLEAR_VARS)
LOCAL_MODULE := myffmpeg7
LOCAL_SRC_FILES := libavdevice.so
include $(PREBUILT_SHARED_LIBRARY)
#ffmpeg pre-built modules
#include $(CLEAR_VARS)
#LOCAL_MODULE := myffmpeg8
#LOCAL_SRC_FILES := libpostproc.so
#include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := your-list of shared-lib-name
LOCAL_SHARED_LIBRARIES := myffmpeg1 myffmpeg2 myffmpeg3 myffmpeg4 myffmpeg5 myffmpeg6 myffmpeg7
LOCAL_SRC_FILES := your-list of source-files
# No special compiler flags.
LOCAL_CFLAGS += -fno-builtin-printf -static -O3 -DCORE_FREQ=800 -DLINUX
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog -L--soname-prefix=/system/lib/
include $(BUILD_SHARED_LIBRARY)