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| author | Michael Niedermayer <michaelni@gmx.at> | 2012-09-09 12:59:55 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2012-09-09 13:02:08 +0200 |
| commit | 4819d43d7f0e220b231699e0ac7b0dc906b3147c (patch) | |
| tree | 05d46ccf11140ecfd281e979238cebf1fd9fc43c | |
| parent | b027156b19c2e9a03f79980abbe4a9c422f6d6d6 (diff) | |
| download | ffmpeg-4819d43d7f0e220b231699e0ac7b0dc906b3147c.tar.gz | |
aacpsy: use exp2(f) instead of pow(f)(2,...)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | libavcodec/aacpsy.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c index a9a89888bf..0d44c00cd2 100644 --- a/libavcodec/aacpsy.c +++ b/libavcodec/aacpsy.c @@ -24,6 +24,8 @@ * AAC encoder psychoacoustic model */ +#include "libavutil/libm.h" + #include "avcodec.h" #include "aactab.h" #include "psymodel.h" @@ -333,7 +335,7 @@ static av_cold int psy_3gpp_init(FFPsyContext *ctx) { coeff->spread_low[1] = pow(10.0, -bark_width * en_spread_low); coeff->spread_hi [1] = pow(10.0, -bark_width * en_spread_hi); pe_min = bark_pe * bark_width; - minsnr = pow(2.0f, pe_min / band_sizes[g]) - 1.5f; + minsnr = exp2(pe_min / band_sizes[g]) - 1.5f; coeff->min_snr = av_clipf(1.0f / minsnr, PSY_SNR_25DB, PSY_SNR_1DB); } start = 0; @@ -524,8 +526,8 @@ static float calc_reduction_3gpp(float a, float desired_pe, float pe, { float thr_avg, reduction; - thr_avg = powf(2.0f, (a - pe) / (4.0f * active_lines)); - reduction = powf(2.0f, (a - desired_pe) / (4.0f * active_lines)) - thr_avg; + thr_avg = exp2f((a - pe) / (4.0f * active_lines)); + reduction = exp2f((a - desired_pe) / (4.0f * active_lines)) - thr_avg; return FFMAX(reduction, 0.0f); } @@ -703,7 +705,7 @@ static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel, float delta_sfb_pe = band->norm_fac * norm_fac * delta_pe; float thr = band->thr; - thr *= powf(2.0f, delta_sfb_pe / band->active_lines); + thr *= exp2f(delta_sfb_pe / band->active_lines); if (thr > coeffs[g].min_snr * band->energy && band->avoid_holes == PSY_3GPP_AH_INACTIVE) thr = FFMAX(band->thr, coeffs[g].min_snr * band->energy); band->thr = thr; |