optimize_b_greedy: Avoid left shift of negative value.
Before:
-------
accu_error was always <= 0:
- It was initialized to zero, and
- Became more and more negative through the iterations.
This meant that RDOPT() macro usage on accu_error was causing left shift
of negative value.
Now:
----
- accu_error is initialized to a large positive value.
- It becomes smaller on every iteration but remains >= always.
This is functionally equivalent: verified that there's no change in
output due to this patch.
BUG=aomedia:600
Change-Id: I654572a72234c588c8f332d5b66a5587fc6610b4
diff --git a/av1/encoder/encodemb.c b/av1/encoder/encodemb.c
index c2a99fb..0f1b799 100644
--- a/av1/encoder/encodemb.c
+++ b/av1/encoder/encodemb.c
@@ -218,7 +218,9 @@
const int ctx0 = ctx;
/* Record the r-d cost */
int64_t accu_rate = 0;
- int64_t accu_error = 0;
+ // Initialized to the worst possible error for the largest transform size.
+ // This ensures that it never goes negative.
+ int64_t accu_error = ((int64_t)1) << 50;
rate0 = get_token_bit_costs(*(token_costs_ptr + band_translate[0]), 0, ctx0,
EOB_TOKEN);
@@ -413,6 +415,7 @@
token_cache[rc] = av1_pt_energy_class[t0];
}
+ assert(accu_error >= 0);
x_prev = qcoeff[rc];
