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

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:

Code (CSharp):

1. F_DECLSPEC F_DLLEXPORT int F_STDCALL AigooGetDSPDescription2(FMOD_DSP_DESCRIPTION *FmodDesc)
2. {
3.  
4. // defines the user interface, maximum distance knob
5. static float distance_mapping_values[] = { 0, 1, 5, 20, 100, 500, 10000 };
6. static float distance_mapping_scale[] = { 0, 1, 2, 3, 4, 4.5, 5 };
7.  
8. // defines the 3D location attributes
9. FMOD_DSP_INIT_PARAMDESC_DATA(p_3d_attributes, "3D Attributes", "",  "",  FMOD_DSP_PARAMETER_DATA_TYPE_3DATTRIBUTES);
10.  
11.  
12. FMOD_DSP_DESCRIPTION Aigoo_Simple_Plugin_Desc =
13. {
14.     FMOD_PLUGIN_SDK_VERSION,
15.     "AigooSimplePlugin6",    // name
16.     0x00010000,     // plug-in version
17.     1,              // number of input buffers to process
18.     1,              // number of output buffers to process
19.     Aigoo_Simple_Plugin_dspcreate,
20.     Aigoo_Simple_Plugin_dsprelease,
21.     Aigoo_Simple_Plugin_dspreset,
22.     Aigoo_Simple_Plugin_dspread,
23.     0,
24.     0,
25.     AIGOO_SIMPLE_PLUGIN_NUM_PARAMETERS,
26.     Aigoo_Simple_Plugin_dspparam,
27.     Aigoo_Simple_Plugin_dspsetparamfloat,
28.     0, // Aigoo_Simple_Plugin_dspsetparamint,
29.     0, // Aigoo_Simple_Plugin_dspsetparambool,
30.     Aigoo_Simple_Plugin_dspsetparamdata,
31.     Aigoo_Simple_Plugin_dspgetparamfloat,
32.     0, // Aigoo_Simple_Plugin_dspgetparamint,
33.     0, // Aigoo_Simple_Plugin_dspgetparambool,
34.     Aigoo_Simple_Plugin_dspgetparamdata,
35.     Aigoo_Simple_Plugin_shouldiprocess,
36.     0,                                      // userdata
37.     Aigoo_Simple_Plugin_sys_register,
38.     Aigoo_Simple_Plugin_sys_deregister,
39.     Aigoo_Simple_Plugin_sys_mix
40. };
41.  
42.  
43. FmodDesc = &Aigoo_Simple_Plugin_Desc;
44.  
45. return 9291983;  //this is to test that I'm able to get this value on C# and iOS side
46. }

C# side:

Code (CSharp):

1. public class AigooPlugInHandler {
2.     [DllImport ("__Internal")]
3.     public static extern int AigooGetDSPDescription2(out IntPtr FmodDesc);
4. }
5.  
6. public class MyAigooClass : MonoBehaviour
7. {
8.     if (Application.platform == RuntimePlatform.IPhonePlayer) {
9.         IntPtr FmodDescPtr;
10.         plugin_result = AigooPlugInHandler.AigooGetDSPDescription2(out FmodDescPtr);
11.         //printing plugin_result returns 9291983 which is the value returned from C
12.         if (FmodDescPtr != IntPtr.Zero)
13.         {
14.             DSP_DESCRIPTION FmodDesc = (DSP_DESCRIPTION)Marshal.PtrToStructure(FmodDescPtr, typeof(DSP_DESCRIPTION));
15.             FmodDesc.numinputbuffers = 1;
16.             ERRCHECK(sys.registerDSP(ref FmodDesc, out mmdsp_handle));
17.         }
18.         else
19.             Console.WriteLine("FmodDescPtr is IntPtr.Zero");  
20.     }
21. }

Thanks,
Carlos

 

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:

Code (CSharp):

1. 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:

Code (CSharp):

1. F_DECLSPEC F_DLLEXPORT int F_STDCALL
2. AigooGetDSPDescription2(FMOD_DSP_DESCRIPTION **ppFmodDesc)
3. {
4.     FMOD_DSP_DESCRIPTION* Aigoo_Simple_Plugin_DescPtr = new FMOD_DSP_DESCRIPTION ();
5.     // initialise Aigoo_Simple_Plugin_DescPtr
6.     .
7.     .
8.     .
9.     *ppFmodDesc = Aigoo_Simple_Plugin_DescPtr;
10.     .
11.     .
12.     .

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

After debug narrowed down the error to this call:

Code (CSharp):

1. DSP_DESCRIPTION FmodDesc = (DSP_DESCRIPTION)Marshal.PtrToStructure(FmodDescPtr, typeof(DSP_DESCRIPTION));