GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavfilter/af_aemphasis.c Lines: 142 193 73.6 %
Date: 2020-09-25 23:16:12 Branches: 27 49 55.1 %

Line Branch Exec Source
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/*
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 * Copyright (c) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen, Damien Zammit and others
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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/opt.h"
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#include "avfilter.h"
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#include "internal.h"
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#include "audio.h"
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26
typedef struct BiquadCoeffs {
27
    double a0, a1, a2, b1, b2;
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} BiquadCoeffs;
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30
typedef struct BiquadD2 {
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    double a0, a1, a2, b1, b2, w1, w2;
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} BiquadD2;
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34
typedef struct RIAACurve {
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    BiquadD2 r1;
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    BiquadD2 brickw;
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    int use_brickw;
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} RIAACurve;
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typedef struct AudioEmphasisContext {
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    const AVClass *class;
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    int mode, type;
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    double level_in, level_out;
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    RIAACurve *rc;
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} AudioEmphasisContext;
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#define OFFSET(x) offsetof(AudioEmphasisContext, x)
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#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
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51
static const AVOption aemphasis_options[] = {
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    { "level_in",      "set input gain", OFFSET(level_in),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, FLAGS },
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    { "level_out",    "set output gain", OFFSET(level_out), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, FLAGS },
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    { "mode",         "set filter mode", OFFSET(mode), AV_OPT_TYPE_INT,   {.i64=0}, 0, 1, FLAGS, "mode" },
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    { "reproduction",              NULL,            0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "mode" },
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    { "production",                NULL,            0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "mode" },
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    { "type",         "set filter type", OFFSET(type), AV_OPT_TYPE_INT,   {.i64=4}, 0, 8, FLAGS, "type" },
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    { "col",                 "Columbia",            0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "type" },
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    { "emi",                      "EMI",            0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "type" },
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    { "bsi",              "BSI (78RPM)",            0, AV_OPT_TYPE_CONST, {.i64=2}, 0, 0, FLAGS, "type" },
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    { "riaa",                    "RIAA",            0, AV_OPT_TYPE_CONST, {.i64=3}, 0, 0, FLAGS, "type" },
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    { "cd",         "Compact Disc (CD)",            0, AV_OPT_TYPE_CONST, {.i64=4}, 0, 0, FLAGS, "type" },
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    { "50fm",               "50µs (FM)",            0, AV_OPT_TYPE_CONST, {.i64=5}, 0, 0, FLAGS, "type" },
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    { "75fm",               "75µs (FM)",            0, AV_OPT_TYPE_CONST, {.i64=6}, 0, 0, FLAGS, "type" },
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    { "50kf",            "50µs (FM-KF)",            0, AV_OPT_TYPE_CONST, {.i64=7}, 0, 0, FLAGS, "type" },
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    { "75kf",            "75µs (FM-KF)",            0, AV_OPT_TYPE_CONST, {.i64=8}, 0, 0, FLAGS, "type" },
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    { NULL }
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};
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AVFILTER_DEFINE_CLASS(aemphasis);
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1587600
static inline double biquad(BiquadD2 *bq, double in)
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{
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1587600
    double n = in;
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1587600
    double tmp = n - bq->w1 * bq->b1 - bq->w2 * bq->b2;
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1587600
    double out = tmp * bq->a0 + bq->w1 * bq->a1 + bq->w2 * bq->a2;
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1587600
    bq->w2 = bq->w1;
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1587600
    bq->w1 = tmp;
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1587600
    return out;
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}
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static int filter_frame(AVFilterLink *inlink, AVFrame *in)
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{
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518
    AVFilterContext *ctx = inlink->dst;
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    AVFilterLink *outlink = ctx->outputs[0];
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518
    AudioEmphasisContext *s = ctx->priv;
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518
    const double *src = (const double *)in->data[0];
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518
    const double level_out = s->level_out;
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    const double level_in = s->level_in;
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    AVFrame *out;
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    double *dst;
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    int n, c;
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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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518
    dst = (double *)out->data[0];
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529718
    for (n = 0; n < in->nb_samples; n++) {
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1587600
        for (c = 0; c < inlink->channels; c++)
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1058400
            dst[c] = level_out * biquad(&s->rc[c].r1, s->rc[c].use_brickw ? biquad(&s->rc[c].brickw, src[c] * level_in) : src[c] * level_in);
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529200
        dst += inlink->channels;
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529200
        src += inlink->channels;
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    }
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    if (in != out)
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        av_frame_free(&in);
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518
    return ff_filter_frame(outlink, out);
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}
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static int query_formats(AVFilterContext *ctx)
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{
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    AVFilterChannelLayouts *layouts;
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    AVFilterFormats *formats;
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    static const enum AVSampleFormat sample_fmts[] = {
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        AV_SAMPLE_FMT_DBL,
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        AV_SAMPLE_FMT_NONE
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    };
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    int ret;
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2
    layouts = ff_all_channel_counts();
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2
    if (!layouts)
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        return AVERROR(ENOMEM);
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2
    ret = ff_set_common_channel_layouts(ctx, layouts);
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2
    if (ret < 0)
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        return 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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2
    ret = ff_set_common_formats(ctx, formats);
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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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    if (!formats)
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        return AVERROR(ENOMEM);
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    return ff_set_common_samplerates(ctx, formats);
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}
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static inline void set_highshelf_rbj(BiquadD2 *bq, double freq, double q, double peak, double sr)
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{
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1
    double A = sqrt(peak);
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1
    double w0 = freq * 2 * M_PI / sr;
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1
    double alpha = sin(w0) / (2 * q);
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1
    double cw0 = cos(w0);
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1
    double tmp = 2 * sqrt(A) * alpha;
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1
    double b0 = 0, ib0 = 0;
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1
    bq->a0 =    A*( (A+1) + (A-1)*cw0 + tmp);
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1
    bq->a1 = -2*A*( (A-1) + (A+1)*cw0);
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1
    bq->a2 =    A*( (A+1) + (A-1)*cw0 - tmp);
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1
        b0 =        (A+1) - (A-1)*cw0 + tmp;
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1
    bq->b1 =    2*( (A-1) - (A+1)*cw0);
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1
    bq->b2 =        (A+1) - (A-1)*cw0 - tmp;
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1
    ib0     = 1 / b0;
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    bq->b1 *= ib0;
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    bq->b2 *= ib0;
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    bq->a0 *= ib0;
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    bq->a1 *= ib0;
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1
    bq->a2 *= ib0;
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1
}
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2
static inline void set_lp_rbj(BiquadD2 *bq, double fc, double q, double sr, double gain)
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{
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2
    double omega = 2.0 * M_PI * fc / sr;
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2
    double sn = sin(omega);
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2
    double cs = cos(omega);
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2
    double alpha = sn/(2 * q);
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2
    double inv = 1.0/(1.0 + alpha);
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    bq->a2 = bq->a0 = gain * inv * (1.0 - cs) * 0.5;
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2
    bq->a1 = bq->a0 + bq->a0;
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    bq->b1 = (-2.0 * cs * inv);
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    bq->b2 = ((1.0 - alpha) * inv);
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2
}
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1
static double freq_gain(BiquadCoeffs *c, double freq, double sr)
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{
190
    double zr, zi;
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1
    freq *= 2.0 * M_PI / sr;
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1
    zr = cos(freq);
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1
    zi = -sin(freq);
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196
    /* |(a0 + a1*z + a2*z^2)/(1 + b1*z + b2*z^2)| */
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2
    return hypot(c->a0 + c->a1*zr + c->a2*(zr*zr-zi*zi), c->a1*zi + 2*c->a2*zr*zi) /
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1
           hypot(1 + c->b1*zr + c->b2*(zr*zr-zi*zi), c->b1*zi + 2*c->b2*zr*zi);
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}
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static int config_input(AVFilterLink *inlink)
202
{
203
    double i, j, k, g, t, a0, a1, a2, b1, b2, tau1, tau2, tau3;
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2
    double cutfreq, gain1kHz, gc, sr = inlink->sample_rate;
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2
    AVFilterContext *ctx = inlink->dst;
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    AudioEmphasisContext *s = ctx->priv;
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    BiquadCoeffs coeffs;
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    int ch;
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210
2
    s->rc = av_calloc(inlink->channels, sizeof(*s->rc));
211
2
    if (!s->rc)
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        return AVERROR(ENOMEM);
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214

2
    switch (s->type) {
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    case 0: //"Columbia"
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        i = 100.;
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        j = 500.;
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        k = 1590.;
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        break;
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    case 1: //"EMI"
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        i = 70.;
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        j = 500.;
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        k = 2500.;
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        break;
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    case 2: //"BSI(78rpm)"
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        i = 50.;
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        j = 353.;
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        k = 3180.;
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        break;
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1
    case 3: //"RIAA"
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    default:
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1
        tau1 = 0.003180;
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1
        tau2 = 0.000318;
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1
        tau3 = 0.000075;
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1
        i = 1. / (2. * M_PI * tau1);
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        j = 1. / (2. * M_PI * tau2);
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        k = 1. / (2. * M_PI * tau3);
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1
        break;
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    case 4: //"CD Mastering"
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        tau1 = 0.000050;
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        tau2 = 0.000015;
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        tau3 = 0.0000001;// 1.6MHz out of audible range for null impact
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        i = 1. / (2. * M_PI * tau1);
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        j = 1. / (2. * M_PI * tau2);
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        k = 1. / (2. * M_PI * tau3);
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        break;
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1
    case 5: //"50µs FM (Europe)"
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1
        tau1 = 0.000050;
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1
        tau2 = tau1 / 20;// not used
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1
        tau3 = tau1 / 50;//
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1
        i = 1. / (2. * M_PI * tau1);
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1
        j = 1. / (2. * M_PI * tau2);
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1
        k = 1. / (2. * M_PI * tau3);
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1
        break;
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    case 6: //"75µs FM (US)"
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        tau1 = 0.000075;
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        tau2 = tau1 / 20;// not used
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        tau3 = tau1 / 50;//
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        i = 1. / (2. * M_PI * tau1);
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        j = 1. / (2. * M_PI * tau2);
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        k = 1. / (2. * M_PI * tau3);
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        break;
263
    }
264
265
2
    i *= 2 * M_PI;
266
2
    j *= 2 * M_PI;
267
2
    k *= 2 * M_PI;
268
269
2
    t = 1. / sr;
270
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    //swap a1 b1, a2 b2
272

2
    if (s->type == 7 || s->type == 8) {
273
1
        double tau = (s->type == 7 ? 0.000050 : 0.000075);
274
1
        double f = 1.0 / (2 * M_PI * tau);
275
1
        double nyq = sr * 0.5;
276
1
        double gain = sqrt(1.0 + nyq * nyq / (f * f)); // gain at Nyquist
277
1
        double cfreq = sqrt((gain - 1.0) * f * f); // frequency
278
1
        double q = 1.0;
279
280
1
        if (s->type == 8)
281
1
            q = pow((sr / 3269.0) + 19.5, -0.25); // somewhat poor curve-fit
282
1
        if (s->type == 7)
283
            q = pow((sr / 4750.0) + 19.5, -0.25);
284
1
        if (s->mode == 0)
285
1
            set_highshelf_rbj(&s->rc[0].r1, cfreq, q, 1. / gain, sr);
286
        else
287
            set_highshelf_rbj(&s->rc[0].r1, cfreq, q, gain, sr);
288
1
        s->rc[0].use_brickw = 0;
289
    } else {
290
1
        s->rc[0].use_brickw = 1;
291
1
        if (s->mode == 0) { // Reproduction
292
1
            g  = 1. / (4.+2.*i*t+2.*k*t+i*k*t*t);
293
1
            a0 = (2.*t+j*t*t)*g;
294
1
            a1 = (2.*j*t*t)*g;
295
1
            a2 = (-2.*t+j*t*t)*g;
296
1
            b1 = (-8.+2.*i*k*t*t)*g;
297
1
            b2 = (4.-2.*i*t-2.*k*t+i*k*t*t)*g;
298
        } else {  // Production
299
            g  = 1. / (2.*t+j*t*t);
300
            a0 = (4.+2.*i*t+2.*k*t+i*k*t*t)*g;
301
            a1 = (-8.+2.*i*k*t*t)*g;
302
            a2 = (4.-2.*i*t-2.*k*t+i*k*t*t)*g;
303
            b1 = (2.*j*t*t)*g;
304
            b2 = (-2.*t+j*t*t)*g;
305
        }
306
307
1
        coeffs.a0 = a0;
308
1
        coeffs.a1 = a1;
309
1
        coeffs.a2 = a2;
310
1
        coeffs.b1 = b1;
311
1
        coeffs.b2 = b2;
312
313
        // the coeffs above give non-normalized value, so it should be normalized to produce 0dB at 1 kHz
314
        // find actual gain
315
        // Note: for FM emphasis, use 100 Hz for normalization instead
316
1
        gain1kHz = freq_gain(&coeffs, 1000.0, sr);
317
        // divide one filter's x[n-m] coefficients by that value
318
1
        gc = 1.0 / gain1kHz;
319
1
        s->rc[0].r1.a0 = coeffs.a0 * gc;
320
1
        s->rc[0].r1.a1 = coeffs.a1 * gc;
321
1
        s->rc[0].r1.a2 = coeffs.a2 * gc;
322
1
        s->rc[0].r1.b1 = coeffs.b1;
323
1
        s->rc[0].r1.b2 = coeffs.b2;
324
    }
325
326
2
    cutfreq = FFMIN(0.45 * sr, 21000.);
327
2
    set_lp_rbj(&s->rc[0].brickw, cutfreq, 0.707, sr, 1.);
328
329
4
    for (ch = 1; ch < inlink->channels; ch++) {
330
2
        memcpy(&s->rc[ch], &s->rc[0], sizeof(RIAACurve));
331
    }
332
333
2
    return 0;
334
}
335
336
2
static av_cold void uninit(AVFilterContext *ctx)
337
{
338
2
    AudioEmphasisContext *s = ctx->priv;
339
2
    av_freep(&s->rc);
340
2
}
341
342
static const AVFilterPad avfilter_af_aemphasis_inputs[] = {
343
    {
344
        .name         = "default",
345
        .type         = AVMEDIA_TYPE_AUDIO,
346
        .config_props = config_input,
347
        .filter_frame = filter_frame,
348
    },
349
    { NULL }
350
};
351
352
static const AVFilterPad avfilter_af_aemphasis_outputs[] = {
353
    {
354
        .name = "default",
355
        .type = AVMEDIA_TYPE_AUDIO,
356
    },
357
    { NULL }
358
};
359
360
AVFilter ff_af_aemphasis = {
361
    .name          = "aemphasis",
362
    .description   = NULL_IF_CONFIG_SMALL("Audio emphasis."),
363
    .priv_size     = sizeof(AudioEmphasisContext),
364
    .priv_class    = &aemphasis_class,
365
    .uninit        = uninit,
366
    .query_formats = query_formats,
367
    .inputs        = avfilter_af_aemphasis_inputs,
368
    .outputs       = avfilter_af_aemphasis_outputs,
369
};