Always use maximum amount of channels for VST2 plugins

Fixes #1184
Fixes #1106

Signed-off-by: falkTX <falktx@falktx.com>

source/backend/plugin/CarlaPluginJuce.cpp

@@ -40,6 +40,7 @@
 #define JUCE_GUI_BASICS_INCLUDE_XHEADERS 1
 #include "AppConfig.h"
 #include "juce_audio_processors/juce_audio_processors.h"
+#include "juce_audio_processors/format_types/juce_VSTInterface.h"
 #include "juce_gui_basics/juce_gui_basics.h"
 
 #if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))
@@ -477,6 +478,16 @@ public:
         aOuts  = static_cast<uint32_t>(std::max(fInstance->getTotalNumOutputChannels(), 0));
         params = static_cast<uint32_t>(std::max(fInstance->getNumParameters(), 0));
 
+        if (getType() == PLUGIN_VST2)
+        {
+            if (VstEffectInterface* const vst
+                = reinterpret_cast<VstEffectInterface*>(fInstance->getPlatformSpecificData()))
+            {
+                aIns  = std::max(aIns, static_cast<uint32_t>(std::max(vst->numInputChannels, 0)));
+                aOuts = std::max(aOuts, static_cast<uint32_t>(std::max(vst->numOutputChannels, 0)));
+            }
+        }
+
         if (fInstance->acceptsMidi())
         {
             mIns = 1;
@@ -672,7 +683,10 @@ public:
         if (mOuts > 0)
             pData->extraHints |= PLUGIN_EXTRA_HINT_HAS_MIDI_OUT;
 
-        fInstance->setPlayConfigDetails(static_cast<int>(aIns), static_cast<int>(aOuts), pData->engine->getSampleRate(), static_cast<int>(pData->engine->getBufferSize()));
+        fInstance->setPlayConfigDetails(static_cast<int>(aIns),
+                                        static_cast<int>(aOuts),
+                                        pData->engine->getSampleRate(),
+                                        static_cast<int>(pData->engine->getBufferSize()));
 
         bufferSizeChanged(pData->engine->getBufferSize());
         reloadPrograms(true);

source/backend/utils/CachedPlugins.cpp

@@ -153,7 +153,7 @@ static const CarlaCachedPluginInfo* get_cached_plugin_lv2(Lv2WorldClass& lv2Worl
 
         if (char* const bundle = lilv_file_uri_parse(lilvPlugin.get_bundle_uri().as_uri(), nullptr))
         {
-            File fbundle(bundle);
+            water::File fbundle(bundle);
             lilv_free(bundle);
 
             suri = (fbundle.getFileName() + CARLA_OS_SEP).toRawUTF8() + suri;

source/discovery/carla-discovery.cpp

@@ -50,7 +50,12 @@
 
 #include "CarlaLadspaUtils.hpp"
 #include "CarlaLv2Utils.hpp"
-#include "CarlaVstUtils.hpp"
+
+#ifdef USING_JUCE_FOR_VST2
+# include "juce_audio_processors/format_types/juce_VSTInterface.h"
+#else
+# include "CarlaVstUtils.hpp"
+#endif
 
 #ifdef CARLA_OS_MAC
 # import <Foundation/Foundation.h>
@@ -733,7 +738,7 @@ static void do_lv2_check(const char* const bundle, const bool doInit)
     const Lilv::Plugins lilvPlugins(lv2World.get_all_plugins());
 
     // Get all plugin URIs in this bundle
-    StringArray URIs;
+    water::StringArray URIs;
 
     LILV_FOREACH(plugins, it, lilvPlugins)
     {
@@ -1470,6 +1475,18 @@ static void do_juce_check(const char* const filename_, const char* const stype,
                 audioIns = instance->getTotalNumInputChannels();
                 audioOuts = instance->getTotalNumOutputChannels();
 
+#if JUCE_PLUGINHOST_VST
+                if (std::strcmp(stype, "VST2") == 0)
+                {
+                    if (VstEffectInterface* const vst
+                        = reinterpret_cast<VstEffectInterface*>(instance->getPlatformSpecificData()))
+                    {
+                        audioIns = std::max(audioIns, std::max(vst->numInputChannels, 0));
+                        audioOuts = std::max(audioOuts, std::max(vst->numOutputChannels, 0));
+                    }
+                }
+#endif
+
                 parameters = instance->getParameters().size();
 
                 if (instance->hasEditor())
@@ -1505,8 +1522,8 @@ static void do_juce_check(const char* const filename_, const char* const stype,
 static void do_fluidsynth_check(const char* const filename, const PluginType type, const bool doInit)
 {
 #ifdef HAVE_FLUIDSYNTH
-    const water::String jfilename = water::String(CharPointer_UTF8(filename));
-    const File file(jfilename);
+    const water::String jfilename = water::String(water::CharPointer_UTF8(filename));
+    const water::File file(jfilename);
 
     if (! file.existsAsFile())
     {