Further speedups possible by getting rid of exp2f...
Signed-off-by: Ganesh Ajjanagadde <gajjanaga...@gmail.com>
---
libavcodec/wmadec.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/libavcodec/wmadec.c b/libavcodec/wmadec.c
index da54182..1a84323 100644
--- a/libavcodec/wmadec.c
+++ b/libavcodec/wmadec.c
@@ -35,6 +35,7 @@
#include "libavutil/attributes.h"
#include "libavutil/internal.h"
+#include "libavutil/libm.h"
#include "avcodec.h"
#include "internal.h"
@@ -164,7 +165,7 @@ static av_cold void wma_lsp_to_curve_init(WMACodecContext
*s, int frame_len)
/* tables for x^-0.25 computation */
for (i = 0; i < 256; i++) {
e = i - 126;
- s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
+ s->lsp_pow_e_table[i] = exp2f(e * -0.25);
}
/* NOTE: these two tables are needed to avoid two operations in
@@ -173,7 +174,7 @@ static av_cold void wma_lsp_to_curve_init(WMACodecContext
*s, int frame_len)
for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
m = (1 << LSP_POW_BITS) + i;
a = (float) m * (0.5 / (1 << LSP_POW_BITS));
- a = pow(a, -0.25);
+ a = 1/sqrt(sqrt(a));
s->lsp_pow_m_table1[i] = 2 * a - b;
s->lsp_pow_m_table2[i] = b - a;
b = a;
--
2.7.0
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
