1# For more information about using CMake with Android Studio, read the
 2# documentation: https://d.android.com/studio/projects/add-native-code.html
 3
 4# Sets the minimum version of CMake required to build the native library.
 5
 6cmake_minimum_required(VERSION 3.10.2)
 7
 8# Declares and names the project.
 9
10project("lame")
11
12# Creates and names a library, sets it as either STATIC
13# or SHARED, and provides the relative paths to its source code.
14# You can define multiple libraries, and CMake builds them for you.
15# Gradle automatically packages shared libraries with your APK.
16
17add_library( # Sets the name of the library.
18             native-lib
19
20             # Sets the library as a shared library.
21             SHARED
22
23             # Provides a relative path to your source file(s).
24             native-lib.cpp
25        bitstream.c encoder.c fft.c gain_analysis.c
26        id3tag.c lame.c mpglib_interface.c newmdct.c
27        presets.c psymodel.c quantize.c quantize_pvt.c
28        reservoir.c set_get.c tables.c takehiro.c util.c
29        vbrquantize.c VbrTag.c version.c
30        )
31
32# Searches for a specified prebuilt library and stores the path as a
33# variable. Because CMake includes system libraries in the search path by
34# default, you only need to specify the name of the public NDK library
35# you want to add. CMake verifies that the library exists before
36# completing its build.
37
38find_library( # Sets the name of the path variable.
39              log-lib
40
41              # Specifies the name of the NDK library that
42              # you want CMake to locate.
43              log )
44
45# Specifies libraries CMake should link to your target library. You
46# can link multiple libraries, such as libraries you define in this
47# build script, prebuilt third-party libraries, or system libraries.
48
49target_link_libraries( # Specifies the target library.
50                       native-lib
51
52                       # Links the target library to the log library
53                       # included in the NDK.
54                       ${log-lib} )

 1#include <jni.h>
 2#include <string>
 3#include "lame.h"
 4
 5extern "C" JNIEXPORT jstring JNICALL
 6Java_com_tal_lame_MainActivity_stringFromJNI(
 7        JNIEnv* env,
 8        jobject /* this */) {
 9    std::string hello = "Hello from C++";
10    // 返回LAME的版本信息
11    return env->NewStringUTF(get_lame_version());
12}

 1......
 2android {
 3    ......
 4    defaultConfig {
 5        .......
 6        externalNativeBuild {
 7            cmake {
 8                cppFlags "-frtti -fexceptions"
 9                cFlags "-DSTDC_HEADERS"
10            }
11        }
12    }
13    externalNativeBuild {
14        cmake {
15            path file('src/main/cpp/CMakeLists.txt')
16            version '3.10.2'
17        }
18    }
19    ndkVersion '22.1.7171670'
20}
21
22dependencies {
23		......
24}