无法在iOS上注册FMOD插件(使用Unity3d)

我在C++上创建了一个FMOD插件，并生成了动态库(.dlib(和静态库(.(

我能够成功地使用FMOD Studio GUI的动态库，也能够在Unity3d Mac模拟器中使用它(它从Assets/Plugins中选择动态库。但我在iPhone上运行时遇到了问题。

对于iOS，我需要使用静态库(*.a(，这意味着我必须在Unity3d(C#(中手动加载插件，生成Xcode项目并将其安装在iPhone上。我试着用C实现一个基本函数，并将其加载到C#上，它运行得很好。这意味着静态库是正确生成的，我可以在iPhone上成功加载并使用它。但我无法使用FMOD描述函数。

这是我的代码，当我在iPhone上运行它时，我会得到这个错误：

"FmodDescPtr为IntPtr.Zero">

提前感谢您的帮助！我已经和这个问题斗争了5天，一直没能解决它。

C++侧：

F_DECLSPEC F_DLLEXPORT int F_STDCALL AigooGetDSPDescription2(FMOD_DSP_DESCRIPTION *FmodDesc)
{
// defines the user interface, maximum distance knob
static float distance_mapping_values[] = { 0, 1, 5, 20, 100, 500, 10000 };
static float distance_mapping_scale[] = { 0, 1, 2, 3, 4, 4.5, 5 };
// defines the 3D location attributes
FMOD_DSP_INIT_PARAMDESC_DATA(p_3d_attributes, "3D Attributes", "",  "",  FMOD_DSP_PARAMETER_DATA_TYPE_3DATTRIBUTES);

FMOD_DSP_DESCRIPTION Aigoo_Simple_Plugin_Desc =
{
    FMOD_PLUGIN_SDK_VERSION,
    "AigooSimplePlugin6",    // name
    0x00010000,     // plug-in version
    1,              // number of input buffers to process
    1,              // number of output buffers to process
    Aigoo_Simple_Plugin_dspcreate,
    Aigoo_Simple_Plugin_dsprelease,
    Aigoo_Simple_Plugin_dspreset,
    Aigoo_Simple_Plugin_dspread,
    0,
    0,
    AIGOO_SIMPLE_PLUGIN_NUM_PARAMETERS,
    Aigoo_Simple_Plugin_dspparam,
    Aigoo_Simple_Plugin_dspsetparamfloat,
    0, // Aigoo_Simple_Plugin_dspsetparamint,
    0, // Aigoo_Simple_Plugin_dspsetparambool,
    Aigoo_Simple_Plugin_dspsetparamdata,
    Aigoo_Simple_Plugin_dspgetparamfloat,
    0, // Aigoo_Simple_Plugin_dspgetparamint,
    0, // Aigoo_Simple_Plugin_dspgetparambool,
    Aigoo_Simple_Plugin_dspgetparamdata,
    Aigoo_Simple_Plugin_shouldiprocess,
    0,                                      // userdata
    Aigoo_Simple_Plugin_sys_register,
    Aigoo_Simple_Plugin_sys_deregister,
    Aigoo_Simple_Plugin_sys_mix
};

FmodDesc = &Aigoo_Simple_Plugin_Desc;
return 9291983;  //this is to test that I'm able to get this value on C# and iOS side
}

C#侧：

public class AigooPlugInHandler {
    [DllImport ("__Internal")]
    public static extern int AigooGetDSPDescription2(out IntPtr FmodDesc);
}
public class MyAigooClass : MonoBehaviour 
{
    if (Application.platform == RuntimePlatform.IPhonePlayer) {
        IntPtr FmodDescPtr;
        plugin_result = AigooPlugInHandler.AigooGetDSPDescription2(out FmodDescPtr);
        //printing plugin_result returns 9291983 which is the value returned from C 
        if (FmodDescPtr != IntPtr.Zero)
        {
            DSP_DESCRIPTION FmodDesc = (DSP_DESCRIPTION)Marshal.PtrToStructure(FmodDescPtr, typeof(DSP_DESCRIPTION));
            FmodDesc.numinputbuffers = 1;
            ERRCHECK(sys.registerDSP(ref FmodDesc, out mmdsp_handle));
        }
        else
            Console.WriteLine("FmodDescPtr is IntPtr.Zero");    
    }
}

这是DSP_DESCRIPTION:的原始结构

[StructLayout(LayoutKind.Sequential)] //original:
public struct DSP_DESCRIPTION
{
    public uint pluginsdkversion;                          /* [w] The plugin SDK version this plugin is built for.  set to this to FMOD_PLUGIN_SDK_VERSION defined above. */
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)]
    public char[]                      name;               /* [w] Name of the unit to be displayed in the network. */
    public uint                        version;            /* [w] Plugin writer's version number. */
    public int                         numinputbuffers;    /* [w] Number of input buffers to process.  Use 0 for DSPs that only generate sound and 1 for effects that process incoming sound. */
    public int                         numoutputbuffers;   /* [w] Number of audio output buffers.  Only one output buffer is currently supported. */
    public DSP_CREATECALLBACK          create;             /* [w] Create callback.  This is called when DSP unit is created.  Can be null. */
    public DSP_RELEASECALLBACK         release;            /* [w] Release callback.  This is called just before the unit is freed so the user can do any cleanup needed for the unit.  Can be null. */
    public DSP_RESETCALLBACK           reset;              /* [w] Reset callback.  This is called by the user to reset any history buffers that may need resetting for a filter, when it is to be used or re-used for the first time to its initial clean state.  Use to avoid clicks or artifacts. */
    public DSP_READCALLBACK            read;               /* [w] Read callback.  Processing is done here.  Can be null. */
    public DSP_PROCESS_CALLBACK        process;            /* [w] Process callback.  Can be specified instead of the read callback if any channel format changes occur between input and output.  This also replaces shouldiprocess and should return an error if the effect is to be bypassed.  Can be null. */
    public DSP_SETPOSITIONCALLBACK     setposition;        /* [w] Setposition callback.  This is called if the unit wants to update its position info but not process data.  Can be null. */
    public int                         numparameters;      /* [w] Number of parameters used in this filter.  The user finds this with DSP::getNumParameters */
    public IntPtr                      paramdesc;          /* [w] Variable number of parameter structures. */
    public DSP_SETPARAM_FLOAT_CALLBACK setparameterfloat;  /* [w] This is called when the user calls DSP.setParameterFloat. Can be null. */
    public DSP_SETPARAM_INT_CALLBACK   setparameterint;    /* [w] This is called when the user calls DSP.setParameterInt.   Can be null. */
    public DSP_SETPARAM_BOOL_CALLBACK  setparameterbool;   /* [w] This is called when the user calls DSP.setParameterBool.  Can be null. */
    public DSP_SETPARAM_DATA_CALLBACK  setparameterdata;   /* [w] This is called when the user calls DSP.setParameterData.  Can be null. */
    public DSP_GETPARAM_FLOAT_CALLBACK getparameterfloat;  /* [w] This is called when the user calls DSP.getParameterFloat. Can be null. */
    public DSP_GETPARAM_INT_CALLBACK   getparameterint;    /* [w] This is called when the user calls DSP.getParameterInt.   Can be null. */
    public DSP_GETPARAM_BOOL_CALLBACK  getparameterbool;   /* [w] This is called when the user calls DSP.getParameterBool.  Can be null. */
    public DSP_GETPARAM_DATA_CALLBACK  getparameterdata;   /* [w] This is called when the user calls DSP.getParameterData.  Can be null. */
    public DSP_SHOULDIPROCESS_CALLBACK shouldiprocess;     /* [w] This is called before processing.  You can detect if inputs are idle and return FMOD_OK to process, or any other error code to avoid processing the effect.  Use a count down timer to allow effect tails to process before idling! */
    public IntPtr                      userdata;           /* [w] Optional. Specify 0 to ignore. This is user data to be attached to the DSP unit during creation.  Access via DSP::getUserData. */
}

谢谢，Carlos

FMOD_DSP_DESCRIPTION Aigoo_Simple_Plugin_Desc = ...

F_DECLSPEC F_DLLEXPORT int F_STDCALL
AigooGetDSPDescription2(FMOD_DSP_DESCRIPTION **ppFmodDesc)
{
    FMOD_DSP_DESCRIPTION* Aigoo_Simple_Plugin_DescPtr = new FMOD_DSP_DESCRIPTION ();
    // initialise Aigoo_Simple_Plugin_DescPtr 
    .
    .
    .
    *ppFmodDesc = Aigoo_Simple_Plugin_DescPtr;  
    .
    .
    .