Delphi / Android在哪里搜索母语库？ [英] Where does Delphi/Android search for a native language library?
问题描述
我想添加MIDI功能到Delphi Android应用程序。 MIDI可通过SoniVox库获得，可通过Android NDK访问。 here 可以找到此驱动程序的示例。驱动程序用C编写，NDK可以创建一个可以通过System.loadLibrary调用访问的母语库。
I want to add MIDI capabilities to Delphi Android apps. MIDI is available via the SoniVox library which can be accessed via the Android NDK. An example of this driver can be found here. The driver is written in C, with the NDK it is possible to create a native language library which can be accessed via a System.loadLibrary call.
// MidiDriver - An Android Midi Driver.
// Copyright (C) 2013 Bill Farmer
// Bill Farmer william j farmer [at] yahoo [dot] co [dot] uk.
#include <jni.h>
// for EAS midi
#include "eas.h"
#include "eas_reverb.h"
// determines how many EAS buffers to fill a host buffer
#define NUM_BUFFERS 4
// EAS data
static EAS_DATA_HANDLE pEASData;
const S_EAS_LIB_CONFIG *pLibConfig;
static EAS_PCM *buffer;
static EAS_I32 bufferSize;
static EAS_HANDLE midiHandle;
// init EAS midi
jint
Java_org_drivers_midioutput_MidiDriver_init(JNIEnv *env,
jobject clazz)
{
EAS_RESULT result;
// get the library configuration
pLibConfig = EAS_Config();
if (pLibConfig == NULL || pLibConfig->libVersion != LIB_VERSION)
return 0;
// calculate buffer size
bufferSize = pLibConfig->mixBufferSize * pLibConfig->numChannels *
NUM_BUFFERS;
// init library
if ((result = EAS_Init(&pEASData)) != EAS_SUCCESS)
return 0;
// select reverb preset and enable
EAS_SetParameter(pEASData, EAS_MODULE_REVERB, EAS_PARAM_REVERB_PRESET,
EAS_PARAM_REVERB_CHAMBER);
EAS_SetParameter(pEASData, EAS_MODULE_REVERB, EAS_PARAM_REVERB_BYPASS,
EAS_FALSE);
// open midi stream
if (result = EAS_OpenMIDIStream(pEASData, &midiHandle, NULL) !=
EAS_SUCCESS)
{
EAS_Shutdown(pEASData);
return 0;
}
return bufferSize;
}
// midi config
jintArray
Java_org_drivers_midioutput_MidiDriver_config(JNIEnv *env,
jobject clazz)
{
jboolean isCopy;
if (pLibConfig == NULL)
return NULL;
jintArray configArray = (*env)->NewIntArray(env, 4);
jint *config = (*env)->GetIntArrayElements(env, configArray, &isCopy);
config[0] = pLibConfig->maxVoices;
config[1] = pLibConfig->numChannels;
config[2] = pLibConfig->sampleRate;
config[3] = pLibConfig->mixBufferSize;
(*env)->ReleaseIntArrayElements(env, configArray, config, 0);
return configArray;
}
// midi render
jint
Java_org_drivers_midioutput_MidiDriver_render(JNIEnv *env,
jobject clazz,
jshortArray shortArray)
{
jboolean isCopy;
EAS_RESULT result;
EAS_I32 numGenerated;
EAS_I32 count;
jsize size;
// jbyte* GetByteArrayElements(jbyteArray array, jboolean* isCopy)
// void ReleaseByteArrayElements(jbyteArray array, jbyte* elems,
// void* GetPrimitiveArrayCritical(JNIEnv*, jarray, jboolean*);
// void ReleasePrimitiveArrayCritical(JNIEnv*, jarray, void*, jint);
if (pEASData == NULL)
return 0;
buffer =
(EAS_PCM *)(*env)->GetShortArrayElements(env, shortArray, &isCopy);
size = (*env)->GetArrayLength(env, shortArray);
count = 0;
while (count < size)
{
result = EAS_Render(pEASData, buffer + count,
pLibConfig->mixBufferSize, &numGenerated);
if (result != EAS_SUCCESS)
break;
count += numGenerated * pLibConfig->numChannels;
}
(*env)->ReleaseShortArrayElements(env, shortArray, buffer, 0);
return count;
}
// midi write
jboolean
Java_org_drivers_midioutput_MidiDriver_write(JNIEnv *env,
jobject clazz,
jbyteArray byteArray)
{
jboolean isCopy;
EAS_RESULT result;
jint length;
EAS_U8 *buf;
if (pEASData == NULL || midiHandle == NULL)
return JNI_FALSE;
buf = (EAS_U8 *)(*env)->GetByteArrayElements(env, byteArray, &isCopy);
length = (*env)->GetArrayLength(env, byteArray);
result = EAS_WriteMIDIStream(pEASData, midiHandle, buf, length);
(*env)->ReleaseByteArrayElements(env, byteArray, buf, 0);
if (result != EAS_SUCCESS)
return JNI_FALSE;
return JNI_TRUE;
}
// shutdown EAS midi
jboolean
Java_org_drivers_midioutput_MidiDriver_shutdown(JNIEnv *env,
jobject clazz)
{
EAS_RESULT result;
if (pEASData == NULL || midiHandle == NULL)
return JNI_FALSE;
if ((result = EAS_CloseMIDIStream(pEASData, midiHandle)) != EAS_SUCCESS)
{
EAS_Shutdown(pEASData);
return JNI_FALSE;
}
if ((result = EAS_Shutdown(pEASData)) != EAS_SUCCESS)
return JNI_FALSE;
return JNI_TRUE;
}
我用Eclipse创建了一个Android应用程序，将MidiDriver添加为本地库，把所有东西都运行起来。有了这个驱动，我的应用程序中有MIDI功能。您可以在下面找到MidiDriver代码的大纲。
I created an Android app with Eclipse, added the MidiDriver as a native library and got everything up and running. With this driver I have MIDI capabilities in my app. The outline of the MidiDriver code you will find below.
// MidiDriver - An Android Midi Driver.
// Copyright (C) 2013 Bill Farmer
// Bill Farmer william j farmer [at] yahoo [dot] co [dot] uk.
package org.drivers.midioutput;
import java.io.File;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.util.Log;
// MidiDriver
public class MidiDriver implements Runnable
{
private static final int SAMPLE_RATE = 22050;
private static final int BUFFER_SIZE = 4096;
private Thread thread;
private AudioTrack audioTrack;
private OnMidiStartListener listener;
private short buffer[];
// Constructor
public MidiDriver ()
{
Log.d ("midi", ">> MidiDriver started");
}
public void start ()
{
// Start the thread
thread = new Thread (this, "MidiDriver");
thread.start ();
} // start //
@Override
public void run ()
{
processMidi ();
} // run //
public void stop ()
{
Thread t = thread;
thread = null;
// Wait for the thread to exit
while (t != null && t.isAlive ())
Thread.yield ();
} // stop //
// Process MidiDriver
private void processMidi ()
{
int status = 0;
int size = 0;
// Init midi
if ((size = init()) == 0)
return;
buffer = new short [size];
// Create audio track
audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, SAMPLE_RATE,
AudioFormat.CHANNEL_OUT_STEREO,
AudioFormat.ENCODING_PCM_16BIT,
BUFFER_SIZE, AudioTrack.MODE_STREAM);
if (audioTrack == null)
{
shutdown ();
return;
} // if
// Call listener
if (listener != null)
listener.onMidiStart();
// Play track
audioTrack.play();
// Keep running until stopped
while (thread != null)
{
// Render the audio
if (render(buffer) == 0)
break;
// Write audio to audiotrack
status = audioTrack.write(buffer, 0, buffer.length);
if (status < 0)
break;
} // while
// Render and write the last bit of audio
if (status > 0)
if (render(buffer) > 0)
audioTrack.write(buffer, 0, buffer.length);
// Shut down audio
shutdown();
audioTrack.release();
} // processMidi //
public void setOnMidiStartListener (OnMidiStartListener l)
{
listener = l;
} // setOnMidiStartListener //
public static void load_lib (String libName)
{
File file = new File (libName);
if (file.exists ())
{
System.load (libName);
} else
{
System.loadLibrary (libName);
}
} // Listener interface
public interface OnMidiStartListener
{
public abstract void onMidiStart ();
} // OnMidiStartListener //
// Native midi methods
private native int init ();
public native int [] config ();
private native int render (short a []);
public native boolean write (byte a []);
private native boolean shutdown ();
// Load midi library
static
{
System.loadLibrary ("midi");
}
}
接下来我测试了JNI界面，看看我是否可以通过JNI访问来自Delphi的Java类。也没问题。所以理论上我应该能够通过Java界面访问MidiDriver：酷！我将MidiDriver包装在另一个Java类中：MIDI_Output以便在内部处理接口（我不知道如何在Delphi中连接Java接口）MIDI_Output在必要时创建一个MidiDriver的实例，并从MidiDriver调用函数，这一切都很好从Eclipse运行下面的MIDI_Output的一些部分：
Next I tested the JNI interface to see whether I could access Java classes from Delphi via JNI. No problem either. So theoretically I should be able to access the MidiDriver via a Java interface: cool! I wrapped MidiDriver in a another Java class: MIDI_Output in order to handle the interface internally (I have no idea how to interface a Java interface in Delphi. MIDI_Output creates an instance of MidiDriver and calls functions from MidiDriver when necessary. This all works great when running from Eclipse. Some parts of MIDI_Output below:
package org.drivers.midioutput;
import java.io.IOException;
import org.drivers.midioutput.MidiDriver.OnMidiStartListener;
import android.media.MediaPlayer;
import android.os.Environment;
import android.util.Log;
public class MIDI_Output implements OnMidiStartListener
{
protected MidiDriver midi_driver;
protected MediaPlayer media_player;
public MIDI_Output ()
{
// Create midi driver
Log.d ("midi", ">> Before initializing MIDI driver version 1");
midi_driver = new MidiDriver();
// Set onmidistart listener to this class
if (midi_driver != null)
midi_driver.setOnMidiStartListener (this);
} // MIDI_Output () //
protected void putShort (int m, int n, int v)
{
if (midi_driver != null)
{
byte msg [] = new byte [3];
msg [0] = (byte) m;
msg [1] = (byte) n;
msg [2] = (byte) v;
midi_driver.write (msg);
} // if
} // putShort //
// and much more code
// ...
在上面的例子中，putShort从MidiDriver调用函数写，这是在本机库中定义的函数。这在Java中都可以正常工作，但是在Dellphi实践中，有一点更难，你可能已经猜到了。要更详细地显示调用链，我需要在Delphi中使用这个整体，请看下面的图片。
In the example above putShort calls function write from MidiDriver which is a function defined in the native library. This all works fine in Java but in Dellphi practice is a little harder as you might have guessed. To show in more detail the call chain I need to use this whole contraption in Delphi see the image below.
在 libsonivox / system / lib ）可以找到函数 EAS_WriteMidiStream ，这是从函数写入 libmidi.so （发现无处不在，但也在 / system / lib 和 / vendor / lib ），它在 MidiDriver.java 中声明在 MIDI_Output.apk 从 MIDI_Output.java 中调用，它创建一个新的MidiDriver 并引用 midi_driver.write（...）在同一个软件包的功能 putShort 中。最后应该在Delphi中调用 putShort ，但是它永远不会在那里。
In libsonivox (found in /system/lib) the function EAS_WriteMidiStream can be found, which is called from function write in libmidi.so (found everywhere, but also in /system/lib and /vendor/lib), which is declared in MidiDriver.java in MIDI_Output.apk which is called from MIDI_Output.java which creates a new MidiDriver and refers to midi_driver.write (...) in function putShort of the same package. Finally putShort should be called in Delphi but it never gets there.
当 MIDI_Output 创建新的MidiDriver 它尝试加载 midi 库。该程序无法加载库 midi 。我运行 adb -d logcat ，看看会发生什么，输出如下所示。 Android屏幕上显示的错误消息将突出显示。
It is aborted when MIDI_Output create the new MidiDriver which tries to load the midi library. The program is not able to load the library "midi". I ran adb -d logcat to see what happens and the output is shown below. The error message that is shown on the android screen is highlighted.
D/dalvikvm( 5251): DexOpt: --- BEGIN 'MIDI_Output.apk' (bootstrap=0) ---
D/dalvikvm( 5320): DexOpt: load 50ms, verify+opt 174ms, 1050124 bytes
D/dalvikvm( 5251): DexOpt: --- END 'MIDI_Output.apk' (success) ---
D/dalvikvm( 5251): DEX prep '/storage/emulated/legacy/Data/d/MIDI_Output.apk': u
nzip in 14ms, rewrite 401ms
W/dalvikvm( 5251): dvmFindClassByName rejecting 'org.drivers.midioutput/MIDI_Out
put'
D/midi ( 5251): >> Before initializing MIDI driver version 1
W/dalvikvm( 5251): Exception Ljava/lang/UnsatisfiedLinkError; thrown while initi
alizing Lorg/drivers/midioutput/MidiDriver;
W/System.err( 5251): java.lang.UnsatisfiedLinkError: Couldn't load midi from loa
der dalvik.system.DexClassLoader[DexPathList[[zip file "/storage/sdcard0/Data/d/
MIDI_Output.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]]: findLib
rary returned null
W/System.err( 5251): at java.lang.Runtime.loadLibrary(Runtime.java:358)
W/System.err( 5251): at java.lang.System.loadLibrary(System.java:526)
W/System.err( 5251): at org.drivers.midioutput.MidiDriver.<clinit>(MidiDriver
.java:177)
W/System.err( 5251): at org.drivers.midioutput.MIDI_Output.<init>(MIDI_Output
.java:22)
W/System.err( 5251): at java.lang.Class.newInstanceImpl(Native Method)
W/System.err( 5251): at java.lang.Class.newInstance(Class.java:1208)
W/System.err( 5251): at dalvik.system.NativeStart.run(Native Method)
D/dalvikvm( 5251): GC_FOR_ALLOC freed 795K, 9% free 9091K/9920K, paused 13ms,
total 13ms
D/dalvikvm( 5251): GC_CONCURRENT freed 9K, 4% free 9532K/9920K, paused
2ms+2ms, total 22ms
我明白无法找到该库。麻烦的是，我不知道这个图书馆在哪里被搜索。错误消息提到 / vendor / lib 和 / system / lib 。我将libmidi.so添加到这些库中。我将库添加到应用程序目录 com.embarcadero.MIDI_Output_Project / lib （这是Android存储库的地方），到 / storage / sdcard0 / Data / d / （存储包含Java类的MIDI_Output.apk的目录）。我真的把我的Android系统用libmidi.so。我试图加载 libmidi.so 。
I understand that the library cannot be found. Trouble is, I do not know where this library is searched. The error message mentions /vendor/lib and /system/lib. I added libmidi.so to these libraries. I added the library to the application directory com.embarcadero.MIDI_Output_Project/lib (that is where android stores the library), to /storage/sdcard0/Data/d/ (the directory where MIDI_Output.apk containing the Java classes are stored). I literally sprinkled my android system with libmidi.so. I have tried to load libmidi.so as well.
作为一个测试，我添加了一个非常简单的示例类MIDI_Output包，并调用函数test_int。这没有任何问题。
As a test I added a very simple example class to the MIDI_Output package and called function test_int. This runs without any problems.
package org.drivers.midioutput;
import android.util.Log;
public class class_test
{
public int test_int (int n)
{
int sq = n * n;
String mess = "*** test_int computes " + String.valueOf (sq);
Log.d ("midi", mess);
return n * n;
}
}
我的问题是：DalvikVM在哪个目录中寻找本地库在上述设置（Delphi通过JNI调用Java类和通过NDK调用C库的Java）？
My question is: in which directory is DalvikVM looking for native library in a setup described above (Delphi calling a Java class via JNI and Java calling a C library via NDK)?
第二个问题是：它是一个库搜索路径问题呢？也许Delphi无法通过JNI调用NDK。
A second question: is it a library search path problem at all? Maybe Delphi is not able to call NDK via JNI.
我尽量简单。如果有人认为我应该添加更多的代码，让我知道。非常感谢任何帮助。
I have tried to be as brief as possible. If anyone thinks I should add more code just let me know. Any help is greatly appreciated.
推荐答案
Delphi使用的NDK库应放在您的PlatformSDK的路径> \android-ndk-r8e\platforms\android-14\arch-arm\usr\lib 。我意识到这一点感谢Arioch和Chris直接使用NDK的建议。 Source\rtl\android 目录中的大多数android文件都包含文件 Androidapi.inc ，其中包含以下定义
NDK libraries that are used by Delphi should be placed in <path to your PlatformSDKs>\android-ndk-r8e\platforms\android-14\arch-arm\usr\lib. I realised this thanks the recommendations of Arioch and Chris to use the NDK directly. Most android files in the Source\rtl\android directory include the file Androidapi.inc which contains the following definitions
const
AndroidLib = '/usr/lib/libandroid.so';
AndroidJniGraphicsLib = '/usr/lib/libjnigraphics.so';
AndroidEglLib = '/usr/lib/libEGL.so';
AndroidGlesLib = '/usr/lib/libGLESv1_CM.so';
AndroidGles2Lib = '/usr/lib/libGLESv2.so';
AndroidLogLib = '/usr/lib/liblog.so';
AndroidOpenSlesLib = '/usr/lib/libOpenSLES.so';
目录 / usr / lib 不存在于Nexus-7上，但是我在上面提到的路径中发现了所有在 const 部分中声明的文件。将 libmidi.so 复制到此目录解决了问题。我现在听到没有声音没有那么小的问题。我会尽量解决这个问题，以及直接打电话给NDK。
The directory /usr/lib does not exist on the Nexus-7 but I found it in the path mentioned above with all the files declared in the const part. Copying the libmidi.so to this directory solved the problem. I now have the not so minor problem of hearing no sound. I'll try to solve that now, as well as trying to call the NDK directly.
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