如何在 monodroid 中使用 OpenAL 创建音频上下文？

Posted 2023-03-14

【中文标题】如何在 monodroid 中使用 OpenAL 创建音频上下文？

【英文标题】：How can I create an audio context with OpenAL in monodroid?

【发布时间】：2012-03-17 12:19:25

【问题描述】：

每当我尝试在 monodroid 中创建新的音频上下文时，它都会告诉我 openal32.dll 丢失了；这自然是没有意义的，因为这是 monodroid，并且 openal 包含在 OpenTK 中。

我只能假设我做错了什么，但我之前在 windows 下使用过 OpenTK/OpenAL，并且使用类似的代码管理得很好。

无论如何这里是有问题的代码：

        public Audio()
    
        if (Loaded == false)
        
            Loaded = true;
            try
            
                try Console.WriteLine ("Current: " + AudioContext.CurrentContext.ToString()); catch  Console.WriteLine ("no current context"); 
                try Console.WriteLine ("Default: " + AudioContext.DefaultDevice); catch  Console.WriteLine ("no default device"); 

                Context = new AudioContext();
                ValidContext = true; //we have a valid audio context!
            
            catch (Exception ex)
            
                Console.WriteLine ("Loading the audio context failed.");
                Console.WriteLine (ex.ToString ());
                Console.WriteLine (ex.Message);
                ValidContext = false; //Loading the audio context failed :(
            
        
    

这是输出：

I/monodroid-gc(24762): environment supports jni NewWeakGlobalRef

D/androidGameView(24762): SurfaceCreated

D/libEGL  (24762): egl.cfg not found, using default config

D/libEGL  (24762): loaded /system/lib/egl/libGLES_android.so

I/mono-stdout(24762): no current context

I/mono-stdout(24762): no default device

I/mono-stdout(24762): Loading the audio context failed.

I/mono-stdout(24762): System.TypeInitializationException: An exception was thrown by the type initializer for OpenTK.Audio.AudioContext ---> System.TypeInitializationException: An exception was thrown by the type initializer for OpenTK.Audio.AudioDeviceEnumerator ---> System.DllNotFoundException: openal32.dll

I/mono-stdout(24762):   at (wrapper managed-to-native) OpenTK.Audio.OpenAL.Alc:MakeContextCurrent (intptr)

I/mono-stdout(24762):   at OpenTK.Audio.OpenAL.Alc.MakeContextCurrent (ContextHandle context) [0x00000] in <filename unknown>:0 

I/mono-stdout(24762):   at OpenTK.Audio.AudioDeviceEnumerator..cctor () [0x00000] in <filename unknown>:0 

I/mono-stdout(24762):   --- End of inner exception stack trace ---

I/mono-stdout(24762):   at OpenTK.Audio.AudioContext..cctor () [0x00000] in <filename unknown>:0 

I/mono-stdout(24762):   --- End of inner exception stack trace ---

I/mono-stdout(24762):   at Hardware.Audio..ctor () [0x00000] in <filename unknown>:0 

I/mono-stdout(24762): An exception was thrown by the type initializer for OpenTK.Audio.AudioContext

I/ARMAssembler(24762): generated scanline__00000177:03545444_00009001_00000000 [159 ipp] (215 ins) at [0x4fc138:0x4fc494] in 4168381 ns

【参考方案1】：

openal32.dll 不包含在 OpenTK 中。 OpenTK 只有 OpenAL 的绑定。与作为显卡驱动程序一部分的 opengl32.dll 一样，openal32.dll 必须通过声卡驱动程序（或它的软件实现）安装。

经过快速搜索，看来你需要为Android编译一个OpenAL的软件实现：http://pielot.org/2010/12/14/openal-on-android/

编辑：Android 似乎更喜欢使用较新的 OpenSL ES。如果您有一点时间，可以尝试让 OpenTK 的生成器为您生成 OpenSL ES 绑定。

This other *** question 有几个其他使用 OpenSL 的选项。

【讨论】：

感谢您的帮助，我会考虑尝试编译 OpenAL。