Libffmpeg.so的测试例程

1.       利用ndk自带sample中的hello-jni,将好的libffmpeg.so和ffmpeg源码拷贝到hello-jni的jni目录，我的为F:\android-ndk-r7b\samples\hello-jni\jni。

目录结构如下：

 

2.       修改hello-jni.c

/*

 * Copyright (C) 2009 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 *

 */



#include <string.h>

#include <stdio.h>

#include <android/log.h>

#include <stdlib.h>

#include <jni.h>

#include <ffmpeg/libavcodec/avcodec.h>



/* This is a trivial JNI example where we use a native method

 * to return a new VM String. See the corresponding Java source

 * file located at:

 *

 *   apps/samples/hello-jni/project/src/com/example/HelloJni/HelloJni.java

 */

jstring

Java_com_example_hellojni_HelloJni_stringFromJNI( JNIEnv* env,

                                                  jobject thiz )

{

         char str[50] = {0};

         char ver[25] = {0};

      sprintf(ver, "%d", avcodec_version());

      strcpy(str,"Hello from JNI ! + ffmpeg ver:");

      strcat(str,ver);

      return (*env)->NewStringUTF(env, str);

}

 

3.       修改android.mk如下：

# Copyright (C) 2009 The Android Open Source Project

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#      http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

#

LOCAL_PATH := $(call my-dir)



#copy libffmpeg.so to libs

include $(CLEAR_VARS)

LOCAL_MODULE := libffmpeg-prebuild

LOCAL_SRC_FILES := libffmpeg.so

LOCAL_MODULE_TAGS := prebuild

include $(PREBUILT_SHARED_LIBRARY)



#generate libhello-jni.so to libs

include $(CLEAR_VARS)

PATH_TO_FFMPEG_SOURCE := $(LOCAL_PATH)/ffmpeg

LOCAL_C_INCLUDES += $(PATH_TO_FFMPEG_SOURCE)

#LOCAL_LDLIBS := -lffmpeg

LOCAL_SHARED_LIBRARIES := libffmpeg-prebuild

LOCAL_MODULE    := hello-jni

LOCAL_SRC_FILES := hello-jni.c



include $(BUILD_SHARED_LIBRARY)

4.       ndk编译

在Cygwin命令行里$NDK/ndk-build,会在hello-jni目录下生成连个目录obj,libs.

而生成的.so会在libs/armeabi目录下     

 

 

5.       将工程导入到eclipse,修改hello-jni.java如下:

    static {

        System.loadLibrary("ffmpeg");

        System.loadLibrary("hello-jni");

}

 

 

6.       运行工程:

   

   3475456就是ffmpeg avcodec version.