diff --git a/meshroom/core/attribute.py b/meshroom/core/attribute.py
index 0c9bb563c3..2e6059ff5b 100644
--- a/meshroom/core/attribute.py
+++ b/meshroom/core/attribute.py
@@ -196,6 +196,7 @@ def _set_value(self, value):
             self.requestNodeUpdate()
 
         self.valueChanged.emit()
+        self.validValueChanged.emit()
 
     def upgradeValue(self, exportedValue):
         self._set_value(exportedValue)
diff --git a/meshroom/core/desc.py b/meshroom/core/desc.py
index 05d9478a08..6d8cc2fa85 100644
--- a/meshroom/core/desc.py
+++ b/meshroom/core/desc.py
@@ -303,13 +303,15 @@ def checkValueTypes(self):
 class ChoiceParam(Param):
     """
     """
-    def __init__(self, name, label, description, value, values, exclusive, uid, group='allParams', joinChar=' ', advanced=False, semantic='', enabled=True):
+    def __init__(self, name, label, description, value, values, exclusive, uid, group='allParams', joinChar=' ', advanced=False, semantic='',
+                 enabled=True, validValue=True, errorMessage=""):
         assert values
         self._values = values
         self._exclusive = exclusive
         self._joinChar = joinChar
         self._valueType = type(self._values[0])  # cast to value type
-        super(ChoiceParam, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced, semantic=semantic, enabled=enabled)
+        super(ChoiceParam, self).__init__(name=name, label=label, description=description, value=value, uid=uid, group=group, advanced=advanced,
+                                          semantic=semantic, enabled=enabled, validValue=validValue, errorMessage=errorMessage)
 
     def conformValue(self, val):
         """ Conform 'val' to the correct type and check for its validity """
diff --git a/meshroom/nodes/aliceVision/KeyframeSelection.py b/meshroom/nodes/aliceVision/KeyframeSelection.py
index 6ae6fd4e02..b8270e87c3 100644
--- a/meshroom/nodes/aliceVision/KeyframeSelection.py
+++ b/meshroom/nodes/aliceVision/KeyframeSelection.py
@@ -3,6 +3,9 @@
 import os
 from meshroom.core import desc
 
+# List of supported video extensions (provided by OpenImageIO)
+videoExts = [".avi", ".mov", ".mp4", ".m4a", ".m4v", ".3gp", ".3g2", ".mj2", ".m4v", ".mpg"]
+
 class KeyframeSelectionNodeSize(desc.DynamicNodeSize):
     def computeSize(self, node):
         inputPathsSize = super(KeyframeSelectionNodeSize, self).computeSize(node)
@@ -299,6 +302,8 @@ class KeyframeSelection(desc.AVCommandLineNode):
             value="none",
             values=["none", "exr", "jpg", "png"],
             exclusive=True,
+            validValue=lambda node: not (any(ext in input.value.lower() for ext in videoExts for input in node.inputPaths.value) and node.outputExtension.value == "none"),
+            errorMessage="A video input has been provided. The output extension should be different from 'none'.",
             uid=[0],
         ),
         desc.ChoiceParam(