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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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typedef struct BiquadCoeffs { |
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double a0, a1, a2, b1, b2; |
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} BiquadCoeffs; |
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typedef struct BiquadD2 { |
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double a0, a1, a2, b1, b2, w1, w2; |
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} BiquadD2; |
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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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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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AVFilterContext *ctx = inlink->dst; |
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AVFilterLink *outlink = ctx->outputs[0]; |
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AudioEmphasisContext *s = ctx->priv; |
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const double *src = (const double *)in->data[0]; |
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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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✓✗ |
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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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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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src += inlink->channels; |
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} |
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✗✓ |
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if (in != out) |
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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 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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layouts = ff_all_channel_counts(); |
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✗✓ |
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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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✗✓ |
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if (ret < 0) |
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return ret; |
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formats = ff_make_format_list(sample_fmts); |
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✗✓ |
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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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✗✓ |
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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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✗✓ |
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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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double A = sqrt(peak); |
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double w0 = freq * 2 * M_PI / sr; |
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double alpha = sin(w0) / (2 * q); |
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double cw0 = cos(w0); |
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double tmp = 2 * sqrt(A) * alpha; |
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double b0 = 0, ib0 = 0; |
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bq->a0 = A*( (A+1) + (A-1)*cw0 + tmp); |
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bq->a1 = -2*A*( (A-1) + (A+1)*cw0); |
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bq->a2 = A*( (A+1) + (A-1)*cw0 - tmp); |
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b0 = (A+1) - (A-1)*cw0 + tmp; |
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bq->b1 = 2*( (A-1) - (A+1)*cw0); |
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bq->b2 = (A+1) - (A-1)*cw0 - tmp; |
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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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bq->a2 *= ib0; |
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} |
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static inline void set_lp_rbj(BiquadD2 *bq, double fc, double q, double sr, double gain) |
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{ |
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double omega = 2.0 * M_PI * fc / sr; |
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double sn = sin(omega); |
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double cs = cos(omega); |
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double alpha = sn/(2 * q); |
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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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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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} |
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static double freq_gain(BiquadCoeffs *c, double freq, double sr) |
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{ |
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double zr, zi; |
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192 |
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freq *= 2.0 * M_PI / sr; |
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zr = cos(freq); |
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zi = -sin(freq); |
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/* |(a0 + a1*z + a2*z^2)/(1 + b1*z + b2*z^2)| */ |
197 |
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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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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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201 |
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static int config_input(AVFilterLink *inlink) |
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{ |
203 |
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double i, j, k, g, t, a0, a1, a2, b1, b2, tau1, tau2, tau3; |
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double cutfreq, gain1kHz, gc, sr = inlink->sample_rate; |
205 |
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AVFilterContext *ctx = inlink->dst; |
206 |
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AudioEmphasisContext *s = ctx->priv; |
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BiquadCoeffs coeffs; |
208 |
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int ch; |
209 |
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210 |
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s->rc = av_calloc(inlink->channels, sizeof(*s->rc)); |
211 |
✗✓ |
2 |
if (!s->rc) |
212 |
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return AVERROR(ENOMEM); |
213 |
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214 |
✗✗✗✓
✗✓✗ |
2 |
switch (s->type) { |
215 |
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case 0: //"Columbia" |
216 |
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i = 100.; |
217 |
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j = 500.; |
218 |
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k = 1590.; |
219 |
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break; |
220 |
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case 1: //"EMI" |
221 |
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i = 70.; |
222 |
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j = 500.; |
223 |
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k = 2500.; |
224 |
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break; |
225 |
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case 2: //"BSI(78rpm)" |
226 |
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i = 50.; |
227 |
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j = 353.; |
228 |
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k = 3180.; |
229 |
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break; |
230 |
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1 |
case 3: //"RIAA" |
231 |
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default: |
232 |
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1 |
tau1 = 0.003180; |
233 |
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tau2 = 0.000318; |
234 |
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1 |
tau3 = 0.000075; |
235 |
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1 |
i = 1. / (2. * M_PI * tau1); |
236 |
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j = 1. / (2. * M_PI * tau2); |
237 |
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k = 1. / (2. * M_PI * tau3); |
238 |
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break; |
239 |
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case 4: //"CD Mastering" |
240 |
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tau1 = 0.000050; |
241 |
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tau2 = 0.000015; |
242 |
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tau3 = 0.0000001;// 1.6MHz out of audible range for null impact |
243 |
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i = 1. / (2. * M_PI * tau1); |
244 |
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j = 1. / (2. * M_PI * tau2); |
245 |
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k = 1. / (2. * M_PI * tau3); |
246 |
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break; |
247 |
|
1 |
case 5: //"50µs FM (Europe)" |
248 |
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1 |
tau1 = 0.000050; |
249 |
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tau2 = tau1 / 20;// not used |
250 |
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1 |
tau3 = tau1 / 50;// |
251 |
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1 |
i = 1. / (2. * M_PI * tau1); |
252 |
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1 |
j = 1. / (2. * M_PI * tau2); |
253 |
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1 |
k = 1. / (2. * M_PI * tau3); |
254 |
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1 |
break; |
255 |
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case 6: //"75µs FM (US)" |
256 |
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tau1 = 0.000075; |
257 |
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tau2 = tau1 / 20;// not used |
258 |
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tau3 = tau1 / 50;// |
259 |
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i = 1. / (2. * M_PI * tau1); |
260 |
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j = 1. / (2. * M_PI * tau2); |
261 |
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k = 1. / (2. * M_PI * tau3); |
262 |
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break; |
263 |
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} |
264 |
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265 |
|
2 |
i *= 2 * M_PI; |
266 |
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2 |
j *= 2 * M_PI; |
267 |
|
2 |
k *= 2 * M_PI; |
268 |
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|
269 |
|
2 |
t = 1. / sr; |
270 |
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271 |
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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 |
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|
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 |
|
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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 |
|
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set_highshelf_rbj(&s->rc[0].r1, cfreq, q, gain, sr); |
288 |
|
1 |
s->rc[0].use_brickw = 0; |
289 |
|
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} 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 |
|
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g = 1. / (2.*t+j*t*t); |
300 |
|
|
a0 = (4.+2.*i*t+2.*k*t+i*k*t*t)*g; |
301 |
|
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a1 = (-8.+2.*i*k*t*t)*g; |
302 |
|
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a2 = (4.-2.*i*t-2.*k*t+i*k*t*t)*g; |
303 |
|
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b1 = (2.*j*t*t)*g; |
304 |
|
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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 |
|
|
}; |