From 7e6593e9773773b5f6ad19fe4cdb2334d492493c Mon Sep 17 00:00:00 2001
From: Justin Ruggles <justin.ruggles@gmail.com>
Date: Mon, 9 Jul 2012 10:53:28 -0400
Subject: [PATCH] alac: eliminate 2 unneeded local variables in
bastardized_rice_decompress()
x_modified is just unnecessary, and final_val can be removed by simplifying
the unsigned-to-signed conversion.
---
libavcodec/alac.c | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)
diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index f27992d0560..2aab84cd2ed 100644
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -110,32 +110,23 @@ static void bastardized_rice_decompress(ALACContext *alac,
int sign_modifier = 0;
for (output_count = 0; output_count < output_size; output_count++) {
- int32_t x;
- int32_t x_modified;
- int32_t final_val;
-
- /* standard rice encoding */
- int k; /* size of extra bits */
+ int x, k;
/* read k, that is bits as is */
k = av_log2((history >> 9) + 3);
k = FFMIN(k, alac->rice_limit);
x = decode_scalar(&alac->gb, k, readsamplesize);
-
- x_modified = sign_modifier + x;
- final_val = (x_modified + 1) / 2;
- if (x_modified & 1) final_val *= -1;
-
- output_buffer[output_count] = final_val;
-
+ x += sign_modifier;
sign_modifier = 0;
+ output_buffer[output_count] = (x >> 1) ^ -(x & 1);
+
/* now update the history */
- if (x_modified > 0xffff)
+ if (x > 0xffff)
history = 0xffff;
else
- history += x_modified * rice_history_mult -
- ((history * rice_history_mult) >> 9);
+ history += x * 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)) {
--
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