我正在尝试从我的 Android NDK 应用程序中使用 Google Oboe。当我尝试使用 native-lib.cpp 中的 oboe::AudioStreamBuilder 时，一切正常。但是，当我尝试从一个类中使用 oboe::AudioStreamBuilder 时，我在重建项目时收到错误消息“错误：未定义对 'oboe::AudioStreamBuilder::openStream(oboe::AudioStream**)' 的引用”。
这是可以的 native-lib.cpp ：
#include <jni.h>
#include <string>
#include <android/log.h>
#include "OboeAudioRecorder.h"
extern "C" JNIEXPORT jstring JNICALL
Java_com_example_oboeaudiorecorder_MainActivity_stringFromJNI(
JNIEnv* env,
jobject /* this */) {
std::string hello = "Hello from C++";
return env->NewStringUTF(hello.c_str());
}
extern "C" JNIEXPORT jboolean JNICALL
Java_com_example_oboeaudiorecorder_MainActivity_recordAudio(
JNIEnv * env,
jobject MainActivity
) {
oboe::AudioStreamBuilder builder;
builder.setDirection(oboe::Direction::Input);
builder.setPerformanceMode(oboe::PerformanceMode::LowLatency);
builder.setDeviceId(0);
oboe::AudioStream *stream;
oboe::Result r = builder.openStream(&stream);
if (r != oboe::Result::OK) {
return false;
}
return true;
}
这是无法编译的类：
#include <oboe/Oboe.h>
#include <oboe/AudioStreamBuilder.h>
#include "OboeAudioRecorder.h"
OboeAudioRecorder::OboeAudioRecorder() {
oboe::AudioStreamBuilder builder;
builder.setDirection(oboe::Direction::Input);
builder.setPerformanceMode(oboe::PerformanceMode::LowLatency);
builder.setDeviceId(0);
oboe::AudioStream *stream;
oboe::Result r = builder.openStream(&stream);
if (r != oboe::Result::OK) {
return;
}
}
CMakeLists.txt 文件：
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)
# <Begin> OBOE SPECIFIC
# Set the path to the Oboe directory.
set (OBOE_DIR "../../../../../oboe")
# Add the Oboe library as a subdirectory in your project.
# add_subdirectory tells CMake to look in this directory to
# compile oboe source files using oboe's CMake file.
# ./oboe specifies where the compiled binaries will be stored
add_subdirectory (${OBOE_DIR} ./oboe)
# Specify the path to the Oboe header files.
# This allows targets compiled with this CMake (application code)
# to see public Oboe headers, in order to access its API.
include_directories (${OBOE_DIR}/include)
# <End> OBOE SPECIFIC
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
add_library( # Sets the name of the library.
native-lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
native-lib.cpp )
add_library(
OboeAudioRecorder
SHARED
OboeAudioRecorder.cpp
)
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log )
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
native-lib oboe OboeAudioRecorder
# Links the target library to the log library
# included in the NDK.
${log-lib} )