Not able to register FMOD Plugin on iOS (using Unity3d)

Unity Engine
1

I created a FMOD Plugin on C++ and generated both dynamic library (.dylib) and static library (.a).

I am able to successfully use the dynamic library with FMOD Studio GUI and also I’m able to use it in Unity3d Mac simulator (which picks the dynamic library from Assets/Plugins. But I’m having problems getting things working on the iPhone.

For iOS, I need to use the static library (*.a), which means I have to manually load the plugin in Unity3d (C#), generate the Xcode project and installed it on the iPhone. I tried implementing a basic function in C and load it on C# and it works fine. That means that static library is generated properly and that I can load it successfully on the iPhone and use it. But I can’t get working the FMOD Description Function.

Here is my code, when I run it in the iPhone, i’m getting this error:

Thanks in advanced for your help! I’ve been struggling with this for 5 days and haven’t been able to solve it.

C++ side:

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# side:

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");  
    }
}

Thanks,
Carlos

2

I got a reply in another forum with this suggestion:

Looks like Aigoo_Simple_Plugin_Desc is being allocated on the stack rather than the heap.
Instead of:
csharp* *FMOD_DSP_DESCRIPTION Aigoo_Simple_Plugin_Desc = ...* *
…try the following. Note how the FMOD_DSP_DESCRIPTION parameter has been changed to a pointer to a pointer:

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;
    .
    .
    .

But after implementing that change I’m getting a new error:

After debug narrowed down the error to this call:DSP_DESCRIPTION FmodDesc = (DSP_DESCRIPTION)Marshal.PtrToStructure(FmodDescPtr, typeof(DSP_DESCRIPTION));