Add test for old LibcameraAllocator

Signed-off-by: William Vinnicombe <[email protected]>

tests/allocator_test.py

@@ -0,0 +1,30 @@
+#!/usr/bin/python3
+
+# Test that the LibcameraAllocator still works, based off switch_mode example
+
+import time
+
+from picamera2 import Picamera2, Preview
+from picamera2.allocators import LibcameraAllocator
+
+picam2 = Picamera2()
+picam2.allocator = LibcameraAllocator(picam2.camera)
+picam2.start_preview(Preview.QTGL)
+
+preview_config = picam2.create_preview_configuration()
+picam2.configure(preview_config)
+
+picam2.start()
+time.sleep(2)
+
+size = picam2.sensor_resolution
+# GPU won't digest images wider than 4096 on a Pi 4.
+if size[0] > 4096:
+    height = size[1] * 4096 // size[0]
+    height -= height % 2
+    size = (4096, height)
+
+other_config = picam2.create_preview_configuration(main={"size": size}, buffer_count=2)
+
+picam2.switch_mode(other_config)
+time.sleep(2)

tests/test_list.txt

@@ -71,3 +71,4 @@ tests/preview_start_stop.py
 tests/quality_check.py
 tests/qt_gl_preview_test.py
 tests/stop_slow_framerate.py
+tests/allocator_test.py