This bit manipulation is equivalent but avoids undefined
shifts and overflows.

Signed-off-by: Mans Rullgard <[email protected]>
---
 libavcodec/apedec.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 6c3d29e..7702b29 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -690,7 +690,7 @@ static void do_apply_filter(APEContext *ctx, int version, 
APEFilter *f,
             /* Update the adaption coefficients */
             absres = FFABS(res);
             if (absres)
-                *f->adaptcoeffs = ((res & (1<<31)) - (1<<30)) >>
+                *f->adaptcoeffs = ((res & (-1<<31)) ^ (-1<<30)) >>
                                   (25 + (absres <= f->avg*3) + (absres <= 
f->avg*4/3));
             else
                 *f->adaptcoeffs = 0;
-- 
1.7.7.4

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