shithub: dav1d

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Clipping in the second weight of SGRProj is useless

It was found by Christopher "Monty" Montgomery that when a value
between 224 and 96 is clipped between -32 and 95, the resulting
value will always be 95.

--- a/src/decode.c

+++ b/src/decode.c

@@ -2415,7 +2415,7 @@

         lr->sgr_weights[1] = dav1d_sgr_params[idx][1] ?

             dav1d_msac_decode_subexp(&ts->msac,

                 ts->lr_ref[p]->sgr_weights[1] + 32, 128, 4) - 32 :

-            iclip(128 - lr->sgr_weights[0], -32, 95);

+            95;

         memcpy(lr->filter_v, ts->lr_ref[p]->filter_v, sizeof(lr->filter_v));

         memcpy(lr->filter_h, ts->lr_ref[p]->filter_h, sizeof(lr->filter_h));

         ts->lr_ref[p] = lr;