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authorReimar Döffinger <Reimar.Doeffinger@gmx.de>2010-01-12 23:02:07 +0000
committerReimar Döffinger <Reimar.Doeffinger@gmx.de>2010-01-12 23:02:07 +0000
commit1460c79097b19c9ff0413df4d8d651dd5c1a9983 (patch)
treea4b220a0da0dc543a0449804b869208d97d9ef23 /libavcodec/ac3dec.c
parent188d3c510dd166656223afc5fbcf6c424a41e0ca (diff)
downloadffmpeg-1460c79097b19c9ff0413df4d8d651dd5c1a9983.tar.gz
Use MULH instead of 64x64 multiplication, around 5% overall speedup on Intel Atom.
Patch by myself and Yuriy Kaminskiy [yumkam mail ru] Originally committed as revision 21175 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/ac3dec.c')
-rw-r--r--libavcodec/ac3dec.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index 82091bc6e3..ba7ae16711 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -420,10 +420,9 @@ static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
int band_end = bin + s->cpl_band_sizes[band];
for (ch = 1; ch <= s->fbw_channels; ch++) {
if (s->channel_in_cpl[ch]) {
- int64_t cpl_coord = s->cpl_coords[ch][band];
+ int cpl_coord = s->cpl_coords[ch][band] << 5;
for (bin = band_start; bin < band_end; bin++) {
- s->fixed_coeffs[ch][bin] = ((int64_t)s->fixed_coeffs[CPL_CH][bin] *
- cpl_coord) >> 23;
+ s->fixed_coeffs[ch][bin] = MULH(s->fixed_coeffs[CPL_CH][bin] << 4, cpl_coord);
}
if (ch == 2 && s->phase_flags[band]) {
for (bin = band_start; bin < band_end; bin++)