alac: adjust conditions for updating entropy decoder history

avoids some unnecessary arithmetic in certain situations
13 years ago · 6fd8a28b59
parent a06fdadd97
commit 6fd8a28b59
1 changed files with 3 additions and 3 deletions
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@ -131,11 +131,11 @@ static void bastardized_rice_decompress(ALACContext *alac,
        sign_modifier = 0;

        /* now update the history */
-        history += x_modified * rice_history_mult -
-                    ((history * rice_history_mult) >> 9);
-
        if (x_modified > 0xffff)
            history = 0xffff;
+        else
+            history += x_modified * rice_history_mult -
+                        ((history * rice_history_mult) >> 9);

        /* special case: there may be compressed blocks of 0 */
        if ((history < 128) && (output_count+1 < output_size)) {