Android Audio代码分析6

在看AudioSessionId相关代码的时候了解到，共用一个AudioSessionId的AudioTrack和MediaPlayer会共用一个AudioEffect。

今天就来看看AudioEffect是个什么东东。

看这个类的目的，主要是为了搞清楚AudioEffect是个什么东东。

打算重点看看类的介绍及其构造函数上。

*****************************************源码*************************************************

public class AudioEffect {

    static {

        System.loadLibrary("audioeffect_jni");

        native_init();

    }

...

    public AudioEffect(UUID type, UUID uuid, int priority, int audioSession)

            throws IllegalArgumentException, UnsupportedOperationException,

            RuntimeException {

        int[] id = new int[1];

        Descriptor[] desc = new Descriptor[1];

        // native initialization

        int initResult = native_setup(new WeakReference<AudioEffect>(this),

                type.toString(), uuid.toString(), priority, audioSession, id,

                desc);

        if (initResult != SUCCESS && initResult != ALREADY_EXISTS) {

            Log.e(TAG, "Error code " + initResult

                    + " when initializing AudioEffect.");

            switch (initResult) {

            case ERROR_BAD_VALUE:

                throw (new IllegalArgumentException("Effect type: " + type

                        + " not supported."));

            case ERROR_INVALID_OPERATION:

                throw (new UnsupportedOperationException(

                        "Effect library not loaded"));

            default:

                throw (new RuntimeException(

                        "Cannot initialize effect engine for type: " + type

                                + "Error: " + initResult));

            }

        }

        mId = id[0];

        mDescriptor = desc[0];

        synchronized (mStateLock) {<