config option to allow using custom interp factor

Code/Form1.Designer.cs

@@ -322,6 +322,7 @@
             this.interpFactorCombox.Size = new System.Drawing.Size(100, 23);
             this.interpFactorCombox.TabIndex = 7;
             this.interpFactorCombox.SelectedIndexChanged += new System.EventHandler(this.interpFactorCombox_SelectedIndexChanged);
+            this.interpFactorCombox.TextUpdate += new System.EventHandler(this.interpFactorCombox_SelectedIndexChanged);
             // 
             // label4
             // 

Code/Form1.cs

@@ -50,6 +50,7 @@ namespace Flowframes
             NvApi.Init();
             InitAis();
             InterpolationProgress.preview = previewPicturebox;
+            UnlockInterpFactorIfEnabled();
             RemovePreviewIfDisabled();
             UpdateStepByStepControls();
             Initialized();
@@ -120,6 +121,14 @@ namespace Flowframes
 
         }
 
+        void UnlockInterpFactorIfEnabled ()
+        {
+            if (!Config.GetBool(Config.Key.allowCustomInterpFactor))
+                return;
+
+            interpFactorCombox.DropDownStyle = ComboBoxStyle.DropDown;
+        }
+
         void RemovePreviewIfDisabled ()
         {
             if (!Config.GetBool(Config.Key.disablePreview))
@@ -300,6 +309,8 @@ namespace Flowframes
 
         public void runBtn_Click(object sender, EventArgs e)
         {
+            ValidateFactor();
+
             if (!BatchProcessing.busy)      // Don't load values from gui if batch processing is used
                 Interpolate.current = GetCurrentSettings();
 
@@ -342,7 +353,7 @@ namespace Flowframes
             outModeCombox.SelectedIndex = targetIndex;
         }
 
-        AI GetAi()
+        public AI GetAi()
         {
             return Implementations.networks[aiCombox.SelectedIndex];
         }
@@ -392,15 +403,20 @@ namespace Flowframes
         private void interpFactorCombox_SelectedIndexChanged(object sender, EventArgs e)
         {
             UpdateUiFps();
-            int guiInterpFactor = interpFactorCombox.GetInt();
+            int guiFactor = interpFactorCombox.GetInt();
 
             if (!initialized)
                 return;
 
             string aiName = GetAi().aiName.Replace("_", "-");
 
-            if (!Program.busy && guiInterpFactor > 2 && GetAi().multiPass && Config.GetInt(Config.Key.autoEncMode) > 0 && !Logger.GetLastLine().Contains(aiName))
-                Logger.Log($"Warning: {aiName} doesn't natively support 4x/8x and will run multiple times for {guiInterpFactor}x. Auto-Encode will only work on the last run.");
+            if (!Program.busy && guiFactor > 2 && GetAi().multiPass && Config.GetInt(Config.Key.autoEncMode) > 0 && !Logger.GetLastLine().Contains(aiName))
+                Logger.Log($"Warning: {aiName} doesn't natively support 4x/8x and will run multiple times for {guiFactor}x. Auto-Encode will only work on the last run.");
+        }
+
+        public void ValidateFactor ()
+        {
+            interpFactorCombox.Text = $"x{MainUiFunctions.ValidateInterpFactor(interpFactorCombox.GetInt())}";
         }
 
         public void SetWorking(bool state, bool allowCancel = true)
@@ -542,6 +558,8 @@ namespace Flowframes
 
         private void queueBtn_Click(object sender, EventArgs e)
         {
+            ValidateFactor();
+
             if (BatchProcessing.currentBatchForm != null)
             {
                 BatchProcessing.currentBatchForm.WindowState = FormWindowState.Normal;

Code/IO/Config.cs

@@ -306,6 +306,7 @@ namespace Flowframes.IO
             aiCombox,
             allowConsecutiveSceneChanges,
             allowCustomInputRate,
+            allowCustomInterpFactor,
             allowSymlinkEncoding,
             allowSymlinkImport,
             alwaysWaitForAutoEnc,

Code/Ui/MainUiFunctions.cs

@@ -123,5 +123,28 @@ namespace Flowframes.Ui
                 return null;
             }
         }
+
+        public static int ValidateInterpFactor (int factor)
+        {
+            AI ai = Program.mainForm.GetAi();
+
+            if (factor > 256)
+                return 256;
+
+            if (ai.aiName == Implementations.rifeCuda.aiName)
+            {
+                if (!IsPowerOfTwo(factor))
+                {
+                    return Implementations.rifeCuda.supportedFactors.Last();
+                }
+            }
+
+            return factor;
+        }
+
+        static bool IsPowerOfTwo(int x)
+        {
+            return (x != 0) && ((x & (x - 1)) == 0);
+        }
     }
 }