Improve color accuracy of BT709 frames on CUDA

Author: ahmadsharif1

test/decoders/test_video_decoder_ops.py

@@ -118,8 +118,10 @@ def test_get_frame_at_pts(self, device):
         # return the next frame since the right boundary of the interval is
         # open.
         next_frame, _, _ = get_frame_at_pts(decoder, 6.039367)
-        with pytest.raises(AssertionError):
-            frame_compare_function(next_frame, reference_frame6.to(device))
+        if device == "cpu":
+            # We can only compare exact equality on CPU.
+            with pytest.raises(AssertionError):
+                frame_compare_function(next_frame, reference_frame6.to(device))
 
     @pytest.mark.parametrize("device", cpu_and_cuda())
     def test_get_frame_at_index(self, device):

test/utils.py

@@ -44,7 +44,7 @@ def assert_tensor_equal(*args, **kwargs):
 
 # Asserts that at least `percentage`% of the values are within the absolute tolerance.
 def assert_tensor_close_on_at_least(
-    actual_tensor, ref_tensor, percentage=90, abs_tolerance=20
+    actual_tensor, ref_tensor, percentage=90, abs_tolerance=19
 ):
     assert (
         actual_tensor.device == ref_tensor.device