>From fcc874caec6aa2ae439b476559a7a1ee25aecc4e Mon Sep 17 00:00:00 2001
From: Zeng Zhaoxiu <zhaoxiu.z...@gmail.com>
Date: Sat, 14 Feb 2015 00:37:25 +0800
Subject: [PATCH 2/2] avcodec/apedec: simplify sign conversion
Signed-off-by: Zeng Zhaoxiu <zhaoxiu.z...@gmail.com>
---
libavcodec/apedec.c | 23 +++++------------------
1 file changed, 5 insertions(+), 18 deletions(-)
diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index f1ddf80..536361c 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -505,10 +505,7 @@ static inline int ape_decode_value_3860(APEContext *ctx,
GetBitContext *gb,
rice->k++;
/* Convert to signed */
- if (x & 1)
- return (x >> 1) + 1;
- else
- return -(x >> 1);
+ return ((x >> 1) ^ ((x & 1) - 1)) + 1;
}
static inline int ape_decode_value_3900(APEContext *ctx, APERice *rice)
@@ -542,10 +539,7 @@ static inline int ape_decode_value_3900(APEContext *ctx,
APERice *rice)
update_rice(rice, x);
/* Convert to signed */
- if (x & 1)
- return (x >> 1) + 1;
- else
- return -(x >> 1);
+ return ((x >> 1) ^ ((x & 1) - 1)) + 1;
}
static inline int ape_decode_value_3990(APEContext *ctx, APERice *rice)
@@ -588,10 +582,7 @@ static inline int ape_decode_value_3990(APEContext *ctx,
APERice *rice)
update_rice(rice, x);
/* Convert to signed */
- if (x & 1)
- return (x >> 1) + 1;
- else
- return -(x >> 1);
+ return ((x >> 1) ^ ((x & 1) - 1)) + 1;
}
static void decode_array_0000(APEContext *ctx, GetBitContext *gb,
@@ -634,12 +625,8 @@ static void decode_array_0000(APEContext *ctx,
GetBitContext *gb,
}
}
- for (i = 0; i < blockstodecode; i++) {
- if (out[i] & 1)
- out[i] = (out[i] >> 1) + 1;
- else
- out[i] = -(out[i] >> 1);
- }
+ for (i = 0; i < blockstodecode; i++)
+ out[i] = ((out[i] >> 1) ^ ((out[i] & 1) - 1)) + 1;
}
static void entropy_decode_mono_0000(APEContext *ctx, int blockstodecode)
--
2.1.0
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