而使用的ffmpeg 2.1.1为Android未定义的引用 [英] Undefined references while using ffmpeg 2.1.1 for Android

问题描述

我建立的ffmpeg遵循相同的模式， halfninja的构建：使FFmpeg的主可从Java通过JNI。我建的ffmpeg使用下列选项：

I'm building ffmpeg following the same pattern as halfninja's build: make the ffmpeg's main available from Java through JNI. I built ffmpeg with the following options:

./configure \
    --prefix=$PREFIX \
    --disable-shared \
    --enable-static \
    --disable-doc \
    --disable-ffmpeg \
    --disable-ffplay \
    --disable-ffprobe \
    --disable-ffserver \
    --disable-doc \
    --disable-symver \
    --cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
    --target-os=linux \
    --arch=arm \
    --enable-cross-compile \
    --sysroot=$SYSROOT \
    --extra-cflags="-Os -fpic $ADDI_CFLAGS" \
    --extra-ldflags="$ADDI_LDFLAGS"

$preFIX ，工具链，......被设置为从我的NDK相应的文件夹。 $ ADDI_CFLAGS 设置为 -marm 和 $ ADDI_LDFLAGS 和 $ ADDITIONAL_CONFIGURE_FLAGS 都没有设置。创建生成的静态库：

$PREFIX, TOOLCHAIN, … being set to corresponding folders from my NDK. $ADDI_CFLAGS is set to -marm and $ADDI_LDFLAGS and $ADDITIONAL_CONFIGURE_FLAGS are both unset. The resulting static libraries are created:

$ ls -1 android/arm/lib/
libavcodec.a
libavdevice.a
libavfilter.a
libavformat.a
libavutil.a
libswresample.a
libswscale.a
pkgconfig

我将它们公开与 Android.mk 文件，ffmpeg的正在兴建中的 $ NDK /源/的ffmpeg-2.1.1 ：

I expose them with an Android.mk file, ffmpeg being built in $NDK/sources/ffmpeg-2.1.1:

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavdevice
LOCAL_SRC_FILES:= lib/libavdevice.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavcodec
LOCAL_SRC_FILES:= lib/libavcodec.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavformat
LOCAL_SRC_FILES:= lib/libavformat.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libswscale
LOCAL_SRC_FILES:= lib/libswscale.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavutil
LOCAL_SRC_FILES:= lib/libavutil.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavfilter
LOCAL_SRC_FILES:= lib/libavfilter.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libwsresample
LOCAL_SRC_FILES:= lib/libswresample.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_STATIC_LIBRARY)

那么，到那里，一切都看起来很不错。现在，我尝试建立了的ffmpeg 二进制数作为一个静态库。我复制（并没有改变单个字符现在） ffmpeg.c ， ffmpeg.h ， cmdutils.c ， cmdutils.h ， ffmpeg_opt.c 和 ffmpeg_filter.c 在我的 JNI 文件夹。我也有这个文件夹中的两个直JNI相关的文件（从halfninja的构建复制的，我只是改变了包名）。以下是有关 Android.mk ：

So, up to there, everything looks good. Now, I try to build the ffmpeg binary equivalent as a static library. I copied (and didn't change a single character for now) ffmpeg.c, ffmpeg.h, cmdutils.c, cmdutils.h, ffmpeg_opt.cand ffmpeg_filter.c in my jni folder. I also have two directly JNI-related files in this folder (copied from halfninja's build, I just changed the package name). Here's the relevant Android.mk:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_C_INCLUDES := /Applications/android-ndk-r9b/sources/ffmpeg-2.1.1
LOCAL_CFLAGS := -Wdeprecated-declarations
LOCAL_MODULE := videokit
ANDROID_LIB := -landroid
LOCAL_LDLIBS += -llog -ljnigraphics -lz 
LOCAL_SRC_FILES := videokit/com_rfc_video_ffmpeg_Videokit.c videokit/ffmpeg.c videokit/cmdutils.c videokit/ffmpeg_opt.c videokit/ffmpeg_filter.c
LOCAL_SHARED_LIBRARIES := libavdevice libavformat libavfilter libavcodec libwscale libavutil libswresample libswscale libpostproc
include $(BUILD_SHARED_LIBRARY)
$(call import-module,ffmpeg-2.1.1/android/arm)

一切编译罚款，但不链接。这是第一个错误：

Everything compiles fine, but doesn't link. Here are the first errors:

[armeabi] SharedLibrary  : libvideokit.so
/Applications/android-ndk-r9b/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/videokit/videokit/cmdutils.o: in function print_all_libs_info.constprop.5:jni/videokit/cmdutils.c:1063: error: undefined reference to 'swresample_version'
/Applications/android-ndk-r9b/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/videokit/videokit/cmdutils.o: in function print_all_libs_info.constprop.5:jni/videokit/cmdutils.c:1063: error: undefined reference to 'swresample_configuration'
/Applications/android-ndk-r9b/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/videokit/videokit/cmdutils.o: in function opt_default:jni/videokit/cmdutils.c:558: error: undefined reference to 'swr_get_class'
/Applications/android-ndk-r9b/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/videokit/videokit/cmdutils.o: in function opt_default:jni/videokit/cmdutils.c:561: error: undefined reference to 'swr_alloc'
/Applications/android-ndk-r9b/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/videokit/videokit/cmdutils.o: in function opt_default:jni/videokit/cmdutils.c:563: error: undefined reference to 'swr_free'
/Applications/android-ndk-r9b/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/videokit/videokit/ffmpeg_opt.o: in function show_help_default:jni/videokit/ffmpeg_opt.c:2464: error: undefined reference to 'swr_get_class'

我不明白的是，这些函数的定义，并提供 libswresample.a ，其中我链接到：

arm-linux-androideabi-nm /Applications/android-ndk-r9b/sources/ffmpeg-2.1.1/android/arm/lib/libswresample.a  | grep -i -e swr_get_class -e swresample_version
000001d4 T swr_get_class
00000178 T swresample_version

我是什么做错了吗？难道还有其他的，也许更简单的方法来揭露的ffmpeg作为通过JNI静态库可用？ （我不使用halfninja的，因为我至少需要FFmpeg的1.1，而他是0.9）。

What am I doing wrong? Is there another, maybe simpler way to expose ffmpeg as a static library available via JNI? (I don't use halfninja's because I need at least ffmpeg 1.1, while his is in 0.9).

推荐答案

您的名字变得有点炒：在一个地方，你把它叫做 libwsresample ，其他地方 libswresample 。

Your names got a bit scrambled: in one place, you called it libwsresample, elsewhere libswresample.

检查所有名称的一致性。

Check all names for consistency.

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