FFMpeg on Android, undefined references to libavcodec functions, although it is listed on command line

Question

I have a problem with unresolved references to ffmpeg\'s libavcodec functions, so far failed to find the answer in other places (including my mind) :)

Let me descri

Answer 1

The following Android.mk works for me, including handling the target arch. The result of running the bambuser build.sh is copied from .../build/ffmpeg to /jni/lib/ffmpeg. I'm using PREBUILD_SHARED_LIBRARY rather than PREBUILT_STATIC_LIBRARY as the OP did.

LOCAL_PATH := $(call my-dir)

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

include $(CLEAR_VARS)
LOCAL_MODULE := libavcore
LOCAL_SRC_FILES := lib/ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/lib/ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavdevice
LOCAL_SRC_FILES := lib/ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/lib/ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavfilter
LOCAL_SRC_FILES := lib/ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/lib/ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

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

include $(CLEAR_VARS)
LOCAL_MODULE := libavutil
LOCAL_SRC_FILES := lib/ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/lib/ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libswscale
LOCAL_SRC_FILES := lib/ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/lib/ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)

LOCAL_MODULE    := mynativecode
LOCAL_SRC_FILES := native.c
LOCAL_SHARED_LIBRARIES := libavcore libavdevice libavfilter libavutil libswscale libavformat
LOCAL_LDLIBS := -L$(NDK_PLATFORMS_ROOT)/$(TARGET_PLATFORM)/arch-arm/usr/lib \
                -L$(LOCAL_PATH)/lib/ffmpeg/$(TARGET_ARCH_ABI)/lib \
                -lavcore \
                -lavformat \
                -lavcodec \
                -lavdevice \
                -lavfilter \
                -lavutil \
                -lswscale \
                -llog \
                -lz \
                -ldl \
                -lgcc

include $(BUILD_SHARED_LIBRARY)

I also had to change the bambuser build.sh to modify the --soname-prefix argument to include my package name rather than bambusers.

        FLAGS="--target-os=linux --cross-prefix=arm-linux-androideabi- --arch=arm"
        FLAGS="$FLAGS --sysroot=$SYSROOT"
-       FLAGS="$FLAGS --soname-prefix=/data/data/com.bambuser.broadcaster/lib/"
+       FLAGS="$FLAGS --soname-prefix=/data/data//lib/"
        FLAGS="$FLAGS --enable-shared --disable-symver"
        FLAGS="$FLAGS --enable-small --optimization-flags=-O2"