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Diffstat (limited to 'libavcodec/ac3dsp.c')
-rw-r--r--libavcodec/ac3dsp.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/libavcodec/ac3dsp.c b/libavcodec/ac3dsp.c
index cd4d30b8f2..dccad3b3e8 100644
--- a/libavcodec/ac3dsp.c
+++ b/libavcodec/ac3dsp.c
@@ -19,6 +19,7 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavutil/avassert.h"
#include "avcodec.h"
#include "ac3.h"
#include "ac3dsp.h"
@@ -149,6 +150,27 @@ static int ac3_compute_mantissa_size_c(int mant_cnt[5], uint8_t *bap,
return bits;
}
+static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
+{
+ int i;
+
+ for (i = 0; i < nb_coefs; i++) {
+ int e;
+ int v = abs(coef[i]);
+ if (v == 0)
+ e = 24;
+ else {
+ e = 23 - av_log2(v);
+ if (e >= 24) {
+ e = 24;
+ coef[i] = 0;
+ }
+ av_assert2(e >= 0);
+ }
+ exp[i] = e;
+ }
+}
+
av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
{
c->ac3_exponent_min = ac3_exponent_min_c;
@@ -158,6 +180,7 @@ av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
c->float_to_fixed24 = float_to_fixed24_c;
c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c;
c->compute_mantissa_size = ac3_compute_mantissa_size_c;
+ c->extract_exponents = ac3_extract_exponents_c;
if (ARCH_ARM)
ff_ac3dsp_init_arm(c, bit_exact);