diff options
Diffstat (limited to 'libavcodec/aacpsy.c')
| -rw-r--r-- | libavcodec/aacpsy.c | 35 |
1 files changed, 22 insertions, 13 deletions
diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c index e4b4405144..e399be545d 100644 --- a/libavcodec/aacpsy.c +++ b/libavcodec/aacpsy.c @@ -2,20 +2,20 @@ * AAC encoder psychoacoustic model * Copyright (C) 2008 Konstantin Shishkov * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * Libav is distributed in the hope that it will be useful, + * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -24,6 +24,8 @@ * AAC encoder psychoacoustic model */ +#include "libavutil/libm.h" + #include "avcodec.h" #include "aactab.h" #include "psymodel.h" @@ -292,7 +294,7 @@ static av_cold int psy_3gpp_init(FFPsyContext *ctx) { int i, j, g, start; float prev, minscale, minath, minsnr, pe_min; const int chan_bitrate = ctx->avctx->bit_rate / ctx->avctx->channels; - const int bandwidth = ctx->avctx->cutoff ? ctx->avctx->cutoff : ctx->avctx->sample_rate / 2; + const int bandwidth = ctx->avctx->cutoff ? ctx->avctx->cutoff : AAC_CUTOFF(ctx->avctx); const float num_bark = calc_bark((float)bandwidth); ctx->model_priv_data = av_mallocz(sizeof(AacPsyContext)); @@ -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 +526,11 @@ 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; + if(active_lines == 0.0) + return 0; + + 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); } @@ -536,8 +541,10 @@ static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr, float thr = band->thr; if (band->energy > thr) { - thr = powf(thr, 0.25f) + reduction; - thr = powf(thr, 4.0f); + thr = sqrtf(thr); + thr = sqrtf(thr) + reduction; + thr *= thr; + thr *= thr; /* This deviates from the 3GPP spec to match the reference encoder. * It performs min(thr_reduced, max(thr, energy/min_snr)) only for bands @@ -563,7 +570,7 @@ static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel, AacPsyChannel *pch = &pctx->ch[channel]; int start = 0; int i, w, g; - float desired_bits, desired_pe, delta_pe, reduction, spread_en[128] = {0}; + float desired_bits, desired_pe, delta_pe, reduction= NAN, spread_en[128] = {0}; float a = 0.0f, active_lines = 0.0f, norm_fac = 0.0f; float pe = pctx->chan_bitrate > 32000 ? 0.0f : FFMAX(50.0f, 100.0f - pctx->chan_bitrate * 100.0f / 32000.0f); const int num_bands = ctx->num_bands[wi->num_windows == 8]; @@ -577,13 +584,15 @@ static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel, AacPsyBand *band = &pch->band[w+g]; float form_factor = 0.0f; + float Temp; band->energy = 0.0f; for (i = 0; i < band_sizes[g]; i++) { band->energy += coefs[start+i] * coefs[start+i]; form_factor += sqrtf(fabs(coefs[start+i])); } + Temp = band->energy > 0 ? sqrtf((float)band_sizes[g] / band->energy) : 0; band->thr = band->energy * 0.001258925f; - band->nz_lines = form_factor / powf(band->energy / band_sizes[g], 0.25f); + band->nz_lines = form_factor * sqrtf(Temp); start += band_sizes[g]; } @@ -703,7 +712,7 @@ 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; |