mirror of https://github.com/FFmpeg/FFmpeg.git
Paul B Mahol
4 years ago
parent
d60927b676
commit
637c154a50
6 changed files with 415 additions and 1 deletions
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/*
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* Copyright (c) Paul B Mahol |
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* Copyright (c) Laurent de Soras, 2005 |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "libavutil/channel_layout.h" |
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#include "libavutil/ffmath.h" |
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#include "libavutil/opt.h" |
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#include "avfilter.h" |
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#include "audio.h" |
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#include "formats.h" |
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#define NB_COEFS 16 |
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typedef struct AFreqShift { |
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const AVClass *class; |
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double shift; |
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double c[NB_COEFS]; |
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int64_t in_samples; |
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AVFrame *i1, *o1; |
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AVFrame *i2, *o2; |
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void (*filter_channel)(AVFilterContext *ctx, |
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int nb_samples, |
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int sample_rate, |
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const double *src, double *dst, |
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double *i1, double *o1, |
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double *i2, double *o2); |
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} AFreqShift; |
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static int query_formats(AVFilterContext *ctx) |
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{ |
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AVFilterFormats *formats = NULL; |
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AVFilterChannelLayouts *layouts = NULL; |
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static const enum AVSampleFormat sample_fmts[] = { |
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AV_SAMPLE_FMT_DBLP, |
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AV_SAMPLE_FMT_NONE |
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}; |
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int ret; |
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formats = ff_make_format_list(sample_fmts); |
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if (!formats) |
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return AVERROR(ENOMEM); |
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ret = ff_set_common_formats(ctx, formats); |
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if (ret < 0) |
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return ret; |
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layouts = ff_all_channel_counts(); |
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if (!layouts) |
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return AVERROR(ENOMEM); |
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ret = ff_set_common_channel_layouts(ctx, layouts); |
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if (ret < 0) |
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return ret; |
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formats = ff_all_samplerates(); |
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return ff_set_common_samplerates(ctx, formats); |
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} |
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static void pfilter_channel(AVFilterContext *ctx, |
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int nb_samples, |
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int sample_rate, |
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const double *src, double *dst, |
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double *i1, double *o1, |
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double *i2, double *o2) |
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{ |
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AFreqShift *s = ctx->priv; |
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double *c = s->c; |
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double shift = s->shift * M_PI; |
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double cos_theta = cos(shift); |
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double sin_theta = sin(shift); |
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for (int n = 0; n < nb_samples; n++) { |
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double xn1 = src[n], xn2 = src[n]; |
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double I, Q; |
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for (int j = 0; j < NB_COEFS / 2; j++) { |
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I = c[j] * (xn1 + o2[j]) - i2[j]; |
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i2[j] = i1[j]; |
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i1[j] = xn1; |
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o2[j] = o1[j]; |
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o1[j] = I; |
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xn1 = I; |
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} |
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for (int j = NB_COEFS / 2; j < NB_COEFS; j++) { |
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Q = c[j] * (xn2 + o2[j]) - i2[j]; |
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i2[j] = i1[j]; |
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i1[j] = xn2; |
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o2[j] = o1[j]; |
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o1[j] = Q; |
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xn2 = Q; |
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} |
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Q = o2[NB_COEFS - 1]; |
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dst[n] = I * cos_theta - Q * sin_theta; |
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} |
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} |
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static void ffilter_channel(AVFilterContext *ctx, |
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int nb_samples, |
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int sample_rate, |
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const double *src, double *dst, |
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double *i1, double *o1, |
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double *i2, double *o2) |
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{ |
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AFreqShift *s = ctx->priv; |
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double *c = s->c; |
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double ts = 1. / sample_rate; |
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double shift = s->shift; |
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int64_t N = s->in_samples; |
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for (int n = 0; n < nb_samples; n++) { |
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double xn1 = src[n], xn2 = src[n]; |
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double I, Q, theta; |
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for (int j = 0; j < NB_COEFS / 2; j++) { |
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I = c[j] * (xn1 + o2[j]) - i2[j]; |
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i2[j] = i1[j]; |
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i1[j] = xn1; |
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o2[j] = o1[j]; |
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o1[j] = I; |
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xn1 = I; |
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} |
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for (int j = NB_COEFS / 2; j < NB_COEFS; j++) { |
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Q = c[j] * (xn2 + o2[j]) - i2[j]; |
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i2[j] = i1[j]; |
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i1[j] = xn2; |
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o2[j] = o1[j]; |
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o1[j] = Q; |
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xn2 = Q; |
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} |
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Q = o2[NB_COEFS - 1]; |
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theta = 2. * M_PI * fmod(shift * (N + n) * ts, 1.); |
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dst[n] = I * cos(theta) - Q * sin(theta); |
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} |
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} |
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static void compute_transition_param(double *K, double *Q, double transition) |
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{ |
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double kksqrt, e, e2, e4, k, q; |
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k = tan((1. - transition * 2.) * M_PI / 4.); |
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k *= k; |
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kksqrt = pow(1 - k * k, 0.25); |
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e = 0.5 * (1. - kksqrt) / (1. + kksqrt); |
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e2 = e * e; |
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e4 = e2 * e2; |
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q = e * (1. + e4 * (2. + e4 * (15. + 150. * e4))); |
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*Q = q; |
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*K = k; |
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} |
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static double ipowp(double x, int64_t n) |
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{ |
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double z = 1.; |
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while (n != 0) { |
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if (n & 1) |
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z *= x; |
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n >>= 1; |
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x *= x; |
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} |
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return z; |
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} |
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static double compute_acc_num(double q, int order, int c) |
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{ |
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int64_t i = 0; |
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int j = 1; |
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double acc = 0.; |
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double q_ii1; |
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do { |
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q_ii1 = ipowp(q, i * (i + 1)); |
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q_ii1 *= sin((i * 2 + 1) * c * M_PI / order) * j; |
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acc += q_ii1; |
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j = -j; |
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i++; |
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} while (fabs(q_ii1) > 1e-100); |
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return acc; |
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} |
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static double compute_acc_den(double q, int order, int c) |
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{ |
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int64_t i = 1; |
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int j = -1; |
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double acc = 0.; |
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double q_i2; |
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do { |
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q_i2 = ipowp(q, i * i); |
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q_i2 *= cos(i * 2 * c * M_PI / order) * j; |
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acc += q_i2; |
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j = -j; |
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i++; |
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} while (fabs(q_i2) > 1e-100); |
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return acc; |
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} |
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static double compute_coef(int index, double k, double q, int order) |
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{ |
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const int c = index + 1; |
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const double num = compute_acc_num(q, order, c) * pow(q, 0.25); |
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const double den = compute_acc_den(q, order, c) + 0.5; |
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const double ww = num / den; |
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const double wwsq = ww * ww; |
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const double x = sqrt((1 - wwsq * k) * (1 - wwsq / k)) / (1 + wwsq); |
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const double coef = (1 - x) / (1 + x); |
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return coef; |
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} |
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static void compute_coefs(double *coef_arr, int nbr_coefs, double transition) |
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{ |
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const int order = nbr_coefs * 2 + 1; |
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double k, q; |
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compute_transition_param(&k, &q, transition); |
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for (int n = 0; n < nbr_coefs; n++) |
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coef_arr[(n / 2) + (n & 1) * nbr_coefs / 2] = compute_coef(n, k, q, order); |
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} |
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static int config_input(AVFilterLink *inlink) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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AFreqShift *s = ctx->priv; |
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compute_coefs(s->c, NB_COEFS, 2. * 20. / inlink->sample_rate); |
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s->i1 = ff_get_audio_buffer(inlink, NB_COEFS); |
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s->o1 = ff_get_audio_buffer(inlink, NB_COEFS); |
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s->i2 = ff_get_audio_buffer(inlink, NB_COEFS); |
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s->o2 = ff_get_audio_buffer(inlink, NB_COEFS); |
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if (!s->i1 || !s->o1 || !s->i2 || !s->o2) |
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return AVERROR(ENOMEM); |
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if (!strcmp(ctx->filter->name, "afreqshift")) |
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s->filter_channel = ffilter_channel; |
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else |
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s->filter_channel = pfilter_channel; |
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return 0; |
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} |
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static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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AVFilterLink *outlink = ctx->outputs[0]; |
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AFreqShift *s = ctx->priv; |
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AVFrame *out; |
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if (av_frame_is_writable(in)) { |
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out = in; |
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} else { |
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out = ff_get_audio_buffer(outlink, in->nb_samples); |
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if (!out) { |
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av_frame_free(&in); |
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return AVERROR(ENOMEM); |
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} |
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av_frame_copy_props(out, in); |
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} |
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for (int ch = 0; ch < in->channels; ch++) { |
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s->filter_channel(ctx, in->nb_samples, |
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in->sample_rate, |
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(const double *)in->extended_data[ch], |
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(double *)out->extended_data[ch], |
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(double *)s->i1->extended_data[ch], |
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(double *)s->o1->extended_data[ch], |
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(double *)s->i2->extended_data[ch], |
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(double *)s->o2->extended_data[ch]); |
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} |
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s->in_samples += in->nb_samples; |
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if (out != in) |
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av_frame_free(&in); |
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return ff_filter_frame(outlink, out); |
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} |
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static av_cold void uninit(AVFilterContext *ctx) |
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{ |
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AFreqShift *s = ctx->priv; |
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av_frame_free(&s->i1); |
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av_frame_free(&s->o1); |
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av_frame_free(&s->i2); |
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av_frame_free(&s->o2); |
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} |
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#define OFFSET(x) offsetof(AFreqShift, x) |
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#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM |
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static const AVOption afreqshift_options[] = { |
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{ "shift", "set frequency shift", OFFSET(shift), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -INT_MAX, INT_MAX, FLAGS }, |
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{ NULL } |
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}; |
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AVFILTER_DEFINE_CLASS(afreqshift); |
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static const AVFilterPad inputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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.filter_frame = filter_frame, |
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.config_props = config_input, |
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}, |
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{ NULL } |
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}; |
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static const AVFilterPad outputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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}, |
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{ NULL } |
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}; |
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AVFilter ff_af_afreqshift = { |
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.name = "afreqshift", |
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.description = NULL_IF_CONFIG_SMALL("Apply frequency shifting to input audio."), |
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.query_formats = query_formats, |
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.priv_size = sizeof(AFreqShift), |
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.priv_class = &afreqshift_class, |
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.uninit = uninit, |
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.inputs = inputs, |
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.outputs = outputs, |
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.process_command = ff_filter_process_command, |
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}; |
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static const AVOption aphaseshift_options[] = { |
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{ "shift", "set phase shift", OFFSET(shift), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1.0, 1.0, FLAGS }, |
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{ NULL } |
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}; |
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AVFILTER_DEFINE_CLASS(aphaseshift); |
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AVFilter ff_af_aphaseshift = { |
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.name = "aphaseshift", |
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.description = NULL_IF_CONFIG_SMALL("Apply phase shifting to input audio."), |
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.query_formats = query_formats, |
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.priv_size = sizeof(AFreqShift), |
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.priv_class = &aphaseshift_class, |
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.uninit = uninit, |
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.inputs = inputs, |
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.outputs = outputs, |
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.process_command = ff_filter_process_command, |
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}; |
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