Improve BitBlt:

- recovery for 2 windows with same name of same executable
- clearer message for the above case

Author: Avasam

src/AutoSplit.py

@@ -791,7 +791,10 @@ def __get_capture_for_comparison(self):
             if self.settings_dict["capture_method"] == CaptureMethodEnum.VIDEO_CAPTURE_DEVICE:
                 self.live_image.setText("Waiting for capture device...")
             else:
-                self.live_image.setText("Trying to recover window...")
+                message = "Trying to recover window..."
+                if self.settings_dict["capture_method"] == CaptureMethodEnum.BITBLT:
+                    message += "\n(captured window may be incompatible with BitBlt)"
+                self.live_image.setText(message)
                 recovered = self.capture_method.recover_window(self.settings_dict["captured_window_title"])
                 if recovered:
                     capture, _ = self.capture_method.get_frame()

src/capture_method/BitBltCaptureMethod.py

@@ -17,6 +17,14 @@
 PW_RENDERFULLCONTENT = 0x00000002
 
 
+def is_blank(image: MatLike):
+    """
+    BitBlt can return a balnk buffer. Either because the target is unsupported,
+    or because there's two windows of the same name for the same executable.
+    """
+    return not image.any()
+
+
 class BitBltCaptureMethod(CaptureMethodBase):
     name = "BitBlt"
     short_description = "fastest, least compatible"
@@ -61,11 +69,15 @@ def get_frame(self) -> tuple[MatLike | None, bool]:
                 win32con.SRCCOPY,
             )
             image = np.frombuffer(cast(bytes, bitmap.GetBitmapBits(True)), dtype=np.uint8)
-            image.shape = (selection["height"], selection["width"], BGRA_CHANNEL_COUNT)
         except (win32ui.error, pywintypes.error):
             # Invalid handle or the window was closed while it was being manipulated
             return None, False
 
+        if is_blank(image):
+            image = None
+        else:
+            image.shape = (selection["height"], selection["width"], BGRA_CHANNEL_COUNT)
+
         # Cleanup DC and handle
         try_delete_dc(dc_object)
         try_delete_dc(compatible_dc)