omxil: Try to load the broadcom OMX IL core and host library on the raspberry pi

The host library is intentionally not unloaded, since it starts
background threads when initialized, and the deinit function does
not stop the threads. Therefore, this library cannot be unloaded
once loaded and initialized.
Signed-off-by: Martin Storsjö <martin@martin.st>

modules/codec/omxil/omxil_core.c

@@ -55,6 +55,8 @@ static const char *ppsz_dll_list[] =
 {
 #if defined(USE_IOMX)
     "libiomx.so", /* Not used when using IOMX, the lib should already be loaded */
+#elif defined(RPI_OMX)
+    "/opt/vc/lib/libopenmaxil.so",  /* Broadcom IL core */
 #else
     "libOMX_Core.so", /* TI OMAP IL core */
     "libOmxCore.so", /* Qualcomm IL core */
@@ -63,6 +65,14 @@ static const char *ppsz_dll_list[] =
     0
 };
 
+#ifdef RPI_OMX
+static const char *ppsz_extra_dll_list[] =
+{
+    "/opt/vc/lib/libbcm_host.so",  /* Broadcom host library */
+    0
+};
+#endif
+
 /*****************************************************************************
  * Global OMX Core instance, shared between module instances
  *****************************************************************************/
@@ -77,6 +87,22 @@ OMX_ERRORTYPE (*pf_free_handle) (OMX_HANDLETYPE);
 OMX_ERRORTYPE (*pf_component_enum)(OMX_STRING, OMX_U32, OMX_U32);
 OMX_ERRORTYPE (*pf_get_roles_of_component)(OMX_STRING, OMX_U32 *, OMX_U8 **);
 
+#ifdef RPI_OMX
+static void *extra_dll_handle;
+static void (*pf_host_init)(void);
+static void (*pf_host_deinit)(void);
+
+static void CloseExtraDll()
+{
+    if (pf_host_deinit)
+        pf_host_deinit();
+    // Intentionally not unloading the host library, since it cannot be
+    // unloaded cleanly after it has been initialized.
+}
+#else
+#define CloseExtraDll()
+#endif
+
 int InitOmxCore(vlc_object_t *p_this)
 {
     int i;
@@ -87,6 +113,23 @@ int InitOmxCore(vlc_object_t *p_this)
         return VLC_SUCCESS;
     }
 
+#ifdef RPI_OMX
+    /* Load an extra library first, if available */
+    extra_dll_handle = NULL;
+    for( i = 0; ppsz_extra_dll_list[i]; i++ )
+    {
+        extra_dll_handle = dll_open( ppsz_extra_dll_list[i] );
+        if( extra_dll_handle ) break;
+    }
+    if( extra_dll_handle )
+    {
+        pf_host_init = dlsym( extra_dll_handle, "bcm_host_init" );
+        pf_host_deinit = dlsym( extra_dll_handle, "bcm_host_deinit" );
+        if (pf_host_init)
+            pf_host_init();
+    }
+#endif
+
     /* Load the OMX core */
     for( i = 0; ppsz_dll_list[i]; i++ )
     {
@@ -95,6 +138,7 @@ int InitOmxCore(vlc_object_t *p_this)
     }
     if( !dll_handle )
     {
+        CloseExtraDll();
         vlc_mutex_unlock( &omx_core_mutex );
         return VLC_EGENERIC;
     }
@@ -111,6 +155,7 @@ int InitOmxCore(vlc_object_t *p_this)
         msg_Warn( p_this, "cannot find OMX_* symbols in `%s' (%s)",
                   ppsz_dll_list[i], dlerror() );
         dll_close(dll_handle);
+        CloseExtraDll();
         vlc_mutex_unlock( &omx_core_mutex );
         return VLC_EGENERIC;
     }
@@ -122,6 +167,7 @@ int InitOmxCore(vlc_object_t *p_this)
         msg_Warn( p_this, "OMX_Init failed (%x: %s)", omx_error,
                   ErrorToString(omx_error) );
         dll_close(dll_handle);
+        CloseExtraDll();
         vlc_mutex_unlock( &omx_core_mutex );
         return VLC_EGENERIC;
     }
@@ -138,6 +184,7 @@ void DeinitOmxCore(void)
     {
         pf_deinit();
         dll_close( dll_handle );
+        CloseExtraDll();
     }
     vlc_mutex_unlock( &omx_core_mutex );
 }