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Diffstat (limited to 'libavfilter/af_mcompand.c')
| -rw-r--r-- | libavfilter/af_mcompand.c | 689 |
1 files changed, 689 insertions, 0 deletions
diff --git a/libavfilter/af_mcompand.c b/libavfilter/af_mcompand.c new file mode 100644 index 0000000..02f987a --- /dev/null +++ b/libavfilter/af_mcompand.c @@ -0,0 +1,689 @@ +/* + * COpyright (c) 2002 Daniel Pouzzner + * Copyright (c) 1999 Chris Bagwell + * Copyright (c) 1999 Nick Bailey + * Copyright (c) 2007 Rob Sykes <robs@users.sourceforge.net> + * Copyright (c) 2013 Paul B Mahol + * Copyright (c) 2014 Andrew Kelley + * + * This file is part of FFmpeg. + * + * 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. + * + * 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * audio multiband compand filter + */ + +#include "libavutil/avassert.h" +#include "libavutil/avstring.h" +#include "libavutil/ffmath.h" +#include "libavutil/opt.h" +#include "libavutil/samplefmt.h" +#include "audio.h" +#include "avfilter.h" +#include "internal.h" + +typedef struct CompandSegment { + double x, y; + double a, b; +} CompandSegment; + +typedef struct CompandT { + CompandSegment *segments; + int nb_segments; + double in_min_lin; + double out_min_lin; + double curve_dB; + double gain_dB; +} CompandT; + +#define N 4 + +typedef struct PrevCrossover { + double in; + double out_low; + double out_high; +} PrevCrossover[N * 2]; + +typedef struct Crossover { + PrevCrossover *previous; + size_t pos; + double coefs[3 *(N+1)]; +} Crossover; + +typedef struct CompBand { + CompandT transfer_fn; + double *attack_rate; + double *decay_rate; + double *volume; + double delay; + double topfreq; + Crossover filter; + AVFrame *delay_buf; + size_t delay_size; + ptrdiff_t delay_buf_ptr; + size_t delay_buf_cnt; +} CompBand; + +typedef struct MCompandContext { + const AVClass *class; + + char *args; + + int nb_bands; + CompBand *bands; + AVFrame *band_buf1, *band_buf2, *band_buf3; + int band_samples; + size_t delay_buf_size; +} MCompandContext; + +#define OFFSET(x) offsetof(MCompandContext, x) +#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption mcompand_options[] = { + { "args", "set parameters for each band", OFFSET(args), AV_OPT_TYPE_STRING, { .str = "0.005,0.1 6 -47/-40,-34/-34,-17/-33 100 | 0.003,0.05 6 -47/-40,-34/-34,-17/-33 400 | 0.000625,0.0125 6 -47/-40,-34/-34,-15/-33 1600 | 0.0001,0.025 6 -47/-40,-34/-34,-31/-31,-0/-30 6400 | 0,0.025 6 -38/-31,-28/-28,-0/-25 22000" }, 0, 0, A }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(mcompand); + +static av_cold void uninit(AVFilterContext *ctx) +{ + MCompandContext *s = ctx->priv; + int i; + + av_frame_free(&s->band_buf1); + av_frame_free(&s->band_buf2); + av_frame_free(&s->band_buf3); + + if (s->bands) { + for (i = 0; i < s->nb_bands; i++) { + av_freep(&s->bands[i].attack_rate); + av_freep(&s->bands[i].decay_rate); + av_freep(&s->bands[i].volume); + av_freep(&s->bands[i].transfer_fn.segments); + av_freep(&s->bands[i].filter.previous); + av_frame_free(&s->bands[i].delay_buf); + } + } + av_freep(&s->bands); +} + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterChannelLayouts *layouts; + AVFilterFormats *formats; + static const enum AVSampleFormat sample_fmts[] = { + AV_SAMPLE_FMT_DBLP, + AV_SAMPLE_FMT_NONE + }; + int ret; + + layouts = ff_all_channel_counts(); + if (!layouts) + return AVERROR(ENOMEM); + ret = ff_set_common_channel_layouts(ctx, layouts); + if (ret < 0) + return ret; + + formats = ff_make_format_list(sample_fmts); + if (!formats) + return AVERROR(ENOMEM); + ret = ff_set_common_formats(ctx, formats); + if (ret < 0) + return ret; + + formats = ff_all_samplerates(); + if (!formats) + return AVERROR(ENOMEM); + return ff_set_common_samplerates(ctx, formats); +} + +static void count_items(char *item_str, int *nb_items, char delimiter) +{ + char *p; + + *nb_items = 1; + for (p = item_str; *p; p++) { + if (*p == delimiter) + (*nb_items)++; + } +} + +static void update_volume(CompBand *cb, double in, int ch) +{ + double delta = in - cb->volume[ch]; + + if (delta > 0.0) + cb->volume[ch] += delta * cb->attack_rate[ch]; + else + cb->volume[ch] += delta * cb->decay_rate[ch]; +} + +static double get_volume(CompandT *s, double in_lin) +{ + CompandSegment *cs; + double in_log, out_log; + int i; + + if (in_lin <= s->in_min_lin) + return s->out_min_lin; + + in_log = log(in_lin); + + for (i = 1; i < s->nb_segments; i++) + if (in_log <= s->segments[i].x) + break; + cs = &s->segments[i - 1]; + in_log -= cs->x; + out_log = cs->y + in_log * (cs->a * in_log + cs->b); + + return exp(out_log); +} + +static int parse_points(char *points, int nb_points, double radius, + CompandT *s, AVFilterContext *ctx) +{ + int new_nb_items, num; + char *saveptr = NULL; + char *p = points; + int i; + +#define S(x) s->segments[2 * ((x) + 1)] + for (i = 0, new_nb_items = 0; i < nb_points; i++) { + char *tstr = av_strtok(p, ",", &saveptr); + p = NULL; + if (!tstr || sscanf(tstr, "%lf/%lf", &S(i).x, &S(i).y) != 2) { + av_log(ctx, AV_LOG_ERROR, + "Invalid and/or missing input/output value.\n"); + return AVERROR(EINVAL); + } + if (i && S(i - 1).x > S(i).x) { + av_log(ctx, AV_LOG_ERROR, + "Transfer function input values must be increasing.\n"); + return AVERROR(EINVAL); + } + S(i).y -= S(i).x; + av_log(ctx, AV_LOG_DEBUG, "%d: x=%f y=%f\n", i, S(i).x, S(i).y); + new_nb_items++; + } + num = new_nb_items; + + /* Add 0,0 if necessary */ + if (num == 0 || S(num - 1).x) + num++; + +#undef S +#define S(x) s->segments[2 * (x)] + /* Add a tail off segment at the start */ + S(0).x = S(1).x - 2 * s->curve_dB; + S(0).y = S(1).y; + num++; + + /* Join adjacent colinear segments */ + for (i = 2; i < num; i++) { + double g1 = (S(i - 1).y - S(i - 2).y) * (S(i - 0).x - S(i - 1).x); + double g2 = (S(i - 0).y - S(i - 1).y) * (S(i - 1).x - S(i - 2).x); + int j; + + if (fabs(g1 - g2)) + continue; + num--; + for (j = --i; j < num; j++) + S(j) = S(j + 1); + } + + for (i = 0; i < s->nb_segments; i += 2) { + s->segments[i].y += s->gain_dB; + s->segments[i].x *= M_LN10 / 20; + s->segments[i].y *= M_LN10 / 20; + } + +#define L(x) s->segments[i - (x)] + for (i = 4; i < s->nb_segments; i += 2) { + double x, y, cx, cy, in1, in2, out1, out2, theta, len, r; + + L(4).a = 0; + L(4).b = (L(2).y - L(4).y) / (L(2).x - L(4).x); + + L(2).a = 0; + L(2).b = (L(0).y - L(2).y) / (L(0).x - L(2).x); + + theta = atan2(L(2).y - L(4).y, L(2).x - L(4).x); + len = hypot(L(2).x - L(4).x, L(2).y - L(4).y); + r = FFMIN(radius, len); + L(3).x = L(2).x - r * cos(theta); + L(3).y = L(2).y - r * sin(theta); + + theta = atan2(L(0).y - L(2).y, L(0).x - L(2).x); + len = hypot(L(0).x - L(2).x, L(0).y - L(2).y); + r = FFMIN(radius, len / 2); + x = L(2).x + r * cos(theta); + y = L(2).y + r * sin(theta); + + cx = (L(3).x + L(2).x + x) / 3; + cy = (L(3).y + L(2).y + y) / 3; + + L(2).x = x; + L(2).y = y; + + in1 = cx - L(3).x; + out1 = cy - L(3).y; + in2 = L(2).x - L(3).x; + out2 = L(2).y - L(3).y; + L(3).a = (out2 / in2 - out1 / in1) / (in2 - in1); + L(3).b = out1 / in1 - L(3).a * in1; + } + L(3).x = 0; + L(3).y = L(2).y; + + s->in_min_lin = exp(s->segments[1].x); + s->out_min_lin = exp(s->segments[1].y); + + return 0; +} + +static void square_quadratic(double const *x, double *y) +{ + y[0] = x[0] * x[0]; + y[1] = 2 * x[0] * x[1]; + y[2] = 2 * x[0] * x[2] + x[1] * x[1]; + y[3] = 2 * x[1] * x[2]; + y[4] = x[2] * x[2]; +} + +static int crossover_setup(AVFilterLink *outlink, Crossover *p, double frequency) +{ + double w0 = 2 * M_PI * frequency / outlink->sample_rate; + double Q = sqrt(.5), alpha = sin(w0) / (2*Q); + double x[9], norm; + int i; + + if (w0 > M_PI) + return AVERROR(EINVAL); + + x[0] = (1 - cos(w0))/2; /* Cf. filter_LPF in biquads.c */ + x[1] = 1 - cos(w0); + x[2] = (1 - cos(w0))/2; + x[3] = (1 + cos(w0))/2; /* Cf. filter_HPF in biquads.c */ + x[4] = -(1 + cos(w0)); + x[5] = (1 + cos(w0))/2; + x[6] = 1 + alpha; + x[7] = -2*cos(w0); + x[8] = 1 - alpha; + + for (norm = x[6], i = 0; i < 9; ++i) + x[i] /= norm; + + square_quadratic(x , p->coefs); + square_quadratic(x + 3, p->coefs + 5); + square_quadratic(x + 6, p->coefs + 10); + + p->previous = av_calloc(outlink->channels, sizeof(*p->previous)); + if (!p->previous) + return AVERROR(ENOMEM); + + return 0; +} + +static int config_output(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + MCompandContext *s = ctx->priv; + int ret, ch, i, k, new_nb_items, nb_bands; + char *p = s->args, *saveptr = NULL; + int max_delay_size = 0; + + count_items(s->args, &nb_bands, '|'); + s->nb_bands = FFMAX(1, nb_bands); + + s->bands = av_calloc(nb_bands, sizeof(*s->bands)); + if (!s->bands) + return AVERROR(ENOMEM); + + for (i = 0, new_nb_items = 0; i < nb_bands; i++) { + int nb_points, nb_attacks, nb_items = 0; + char *tstr2, *tstr = av_strtok(p, "|", &saveptr); + char *p2, *p3, *saveptr2 = NULL, *saveptr3 = NULL; + double radius; + + if (!tstr) { + uninit(ctx); + return AVERROR(EINVAL); + } + p = NULL; + + p2 = tstr; + count_items(tstr, &nb_items, ' '); + tstr2 = av_strtok(p2, " ", &saveptr2); + if (!tstr2) { + av_log(ctx, AV_LOG_ERROR, "at least one attacks/decays rate is mandatory\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + p2 = NULL; + p3 = tstr2; + + count_items(tstr2, &nb_attacks, ','); + if (!nb_attacks || nb_attacks & 1) { + av_log(ctx, AV_LOG_ERROR, "number of attacks rate plus decays rate must be even\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + + s->bands[i].attack_rate = av_calloc(outlink->channels, sizeof(double)); + s->bands[i].decay_rate = av_calloc(outlink->channels, sizeof(double)); + s->bands[i].volume = av_calloc(outlink->channels, sizeof(double)); + for (k = 0; k < FFMIN(nb_attacks / 2, outlink->channels); k++) { + char *tstr3 = av_strtok(p3, ",", &saveptr3); + + p3 = NULL; + sscanf(tstr3, "%lf", &s->bands[i].attack_rate[k]); + tstr3 = av_strtok(p3, ",", &saveptr3); + sscanf(tstr3, "%lf", &s->bands[i].decay_rate[k]); + + if (s->bands[i].attack_rate[k] > 1.0 / outlink->sample_rate) { + s->bands[i].attack_rate[k] = 1.0 - exp(-1.0 / (outlink->sample_rate * s->bands[i].attack_rate[k])); + } else { + s->bands[i].attack_rate[k] = 1.0; + } + + if (s->bands[i].decay_rate[k] > 1.0 / outlink->sample_rate) { + s->bands[i].decay_rate[k] = 1.0 - exp(-1.0 / (outlink->sample_rate * s->bands[i].decay_rate[k])); + } else { + s->bands[i].decay_rate[k] = 1.0; + } + } + + for (ch = k; ch < outlink->channels; ch++) { + s->bands[i].attack_rate[ch] = s->bands[i].attack_rate[k - 1]; + s->bands[i].decay_rate[ch] = s->bands[i].decay_rate[k - 1]; + } + + tstr2 = av_strtok(p2, " ", &saveptr2); + if (!tstr2) { + av_log(ctx, AV_LOG_ERROR, "transfer function curve in dB must be set\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + sscanf(tstr2, "%lf", &s->bands[i].transfer_fn.curve_dB); + + radius = s->bands[i].transfer_fn.curve_dB * M_LN10 / 20.0; + + tstr2 = av_strtok(p2, " ", &saveptr2); + if (!tstr2) { + av_log(ctx, AV_LOG_ERROR, "transfer points missing\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + + count_items(tstr2, &nb_points, ','); + s->bands[i].transfer_fn.nb_segments = (nb_points + 4) * 2; + s->bands[i].transfer_fn.segments = av_calloc(s->bands[i].transfer_fn.nb_segments, + sizeof(CompandSegment)); + if (!s->bands[i].transfer_fn.segments) { + uninit(ctx); + return AVERROR(ENOMEM); + } + + ret = parse_points(tstr2, nb_points, radius, &s->bands[i].transfer_fn, ctx); + if (ret < 0) { + av_log(ctx, AV_LOG_ERROR, "transfer points parsing failed\n"); + uninit(ctx); + return ret; + } + + tstr2 = av_strtok(p2, " ", &saveptr2); + if (!tstr2) { + av_log(ctx, AV_LOG_ERROR, "crossover_frequency is missing\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + + new_nb_items += sscanf(tstr2, "%lf", &s->bands[i].topfreq) == 1; + if (s->bands[i].topfreq < 0 || s->bands[i].topfreq >= outlink->sample_rate / 2) { + av_log(ctx, AV_LOG_ERROR, "crossover_frequency should be >=0 and lower than half of sample rate\n"); + uninit(ctx); + return AVERROR(EINVAL); + } + + if (s->bands[i].topfreq != 0) { + ret = crossover_setup(outlink, &s->bands[i].filter, s->bands[i].topfreq); + if (ret < 0) { + uninit(ctx); + return ret; + } + } + + tstr2 = av_strtok(p2, " ", &saveptr2); + if (tstr2) { + sscanf(tstr2, "%lf", &s->bands[i].delay); + max_delay_size = FFMAX(max_delay_size, s->bands[i].delay * outlink->sample_rate); + + tstr2 = av_strtok(p2, " ", &saveptr2); + if (tstr2) { + double initial_volume; + + sscanf(tstr2, "%lf", &initial_volume); + initial_volume = pow(10.0, initial_volume / 20); + + for (k = 0; k < outlink->channels; k++) { + s->bands[i].volume[k] = initial_volume; + } + + tstr2 = av_strtok(p2, " ", &saveptr2); + if (tstr2) { + sscanf(tstr2, "%lf", &s->bands[i].transfer_fn.gain_dB); + } + } + } + } + s->nb_bands = new_nb_items; + + for (i = 0; max_delay_size > 0 && i < s->nb_bands; i++) { + s->bands[i].delay_buf = ff_get_audio_buffer(outlink, max_delay_size); + if (!s->bands[i].delay_buf) + return AVERROR(ENOMEM); + } + s->delay_buf_size = max_delay_size; + + return 0; +} + +#define CONVOLVE _ _ _ _ + +static void crossover(int ch, Crossover *p, + double *ibuf, double *obuf_low, + double *obuf_high, size_t len) +{ + double out_low, out_high; + + while (len--) { + p->pos = p->pos ? p->pos - 1 : N - 1; +#define _ out_low += p->coefs[j] * p->previous[ch][p->pos + j].in \ + - p->coefs[2*N+2 + j] * p->previous[ch][p->pos + j].out_low, j++; + { + int j = 1; + out_low = p->coefs[0] * *ibuf; + CONVOLVE + *obuf_low++ = out_low; + } +#undef _ +#define _ out_high += p->coefs[j+N+1] * p->previous[ch][p->pos + j].in \ + - p->coefs[2*N+2 + j] * p->previous[ch][p->pos + j].out_high, j++; + { + int j = 1; + out_high = p->coefs[N+1] * *ibuf; + CONVOLVE + *obuf_high++ = out_high; + } + p->previous[ch][p->pos + N].in = p->previous[ch][p->pos].in = *ibuf++; + p->previous[ch][p->pos + N].out_low = p->previous[ch][p->pos].out_low = out_low; + p->previous[ch][p->pos + N].out_high = p->previous[ch][p->pos].out_high = out_high; + } +} + +static int mcompand_channel(MCompandContext *c, CompBand *l, double *ibuf, double *obuf, int len, int ch) +{ + int i; + + for (i = 0; i < len; i++) { + double level_in_lin, level_out_lin, checkbuf; + /* Maintain the volume fields by simulating a leaky pump circuit */ + update_volume(l, fabs(ibuf[i]), ch); + + /* Volume memory is updated: perform compand */ + level_in_lin = l->volume[ch]; + level_out_lin = get_volume(&l->transfer_fn, level_in_lin); + + if (c->delay_buf_size <= 0) { + checkbuf = ibuf[i] * level_out_lin; + obuf[i] = checkbuf; + } else { + double *delay_buf = (double *)l->delay_buf->extended_data[ch]; + + /* FIXME: note that this lookahead algorithm is really lame: + the response to a peak is released before the peak + arrives. */ + + /* because volume application delays differ band to band, but + total delay doesn't, the volume is applied in an iteration + preceding that in which the sample goes to obuf, except in + the band(s) with the longest vol app delay. + + the offset between delay_buf_ptr and the sample to apply + vol to, is a constant equal to the difference between this + band's delay and the longest delay of all the bands. */ + + if (l->delay_buf_cnt >= l->delay_size) { + checkbuf = + delay_buf[(l->delay_buf_ptr + + c->delay_buf_size - + l->delay_size) % c->delay_buf_size] * level_out_lin; + delay_buf[(l->delay_buf_ptr + c->delay_buf_size - + l->delay_size) % c->delay_buf_size] = checkbuf; + } + if (l->delay_buf_cnt >= c->delay_buf_size) { + obuf[i] = delay_buf[l->delay_buf_ptr]; + } else { + l->delay_buf_cnt++; + } + delay_buf[l->delay_buf_ptr++] = ibuf[i]; + l->delay_buf_ptr %= c->delay_buf_size; + } + } + + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + MCompandContext *s = ctx->priv; + AVFrame *out, *abuf, *bbuf, *cbuf; + int ch, band, i; + + out = ff_get_audio_buffer(outlink, in->nb_samples); + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + + if (s->band_samples < in->nb_samples) { + av_frame_free(&s->band_buf1); + av_frame_free(&s->band_buf2); + av_frame_free(&s->band_buf3); + + s->band_buf1 = ff_get_audio_buffer(outlink, in->nb_samples); + s->band_buf2 = ff_get_audio_buffer(outlink, in->nb_samples); + s->band_buf3 = ff_get_audio_buffer(outlink, in->nb_samples); + s->band_samples = in->nb_samples; + } + + for (ch = 0; ch < outlink->channels; ch++) { + double *a, *dst = (double *)out->extended_data[ch]; + + for (band = 0, abuf = in, bbuf = s->band_buf2, cbuf = s->band_buf1; band < s->nb_bands; band++) { + CompBand *b = &s->bands[band]; + + if (b->topfreq) { + crossover(ch, &b->filter, (double *)abuf->extended_data[ch], + (double *)bbuf->extended_data[ch], (double *)cbuf->extended_data[ch], in->nb_samples); + } else { + bbuf = abuf; + abuf = cbuf; + } + + if (abuf == in) + abuf = s->band_buf3; + mcompand_channel(s, b, (double *)bbuf->extended_data[ch], (double *)abuf->extended_data[ch], out->nb_samples, ch); + a = (double *)abuf->extended_data[ch]; + for (i = 0; i < out->nb_samples; i++) { + dst[i] += a[i]; + } + + FFSWAP(AVFrame *, abuf, cbuf); + } + } + + out->pts = in->pts; + av_frame_free(&in); + return ff_filter_frame(outlink, out); +} + +static int request_frame(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + int ret; + + ret = ff_request_frame(ctx->inputs[0]); + + return ret; +} + +static const AVFilterPad mcompand_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad mcompand_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .request_frame = request_frame, + .config_props = config_output, + }, + { NULL } +}; + + +AVFilter ff_af_mcompand = { + .name = "mcompand", + .description = NULL_IF_CONFIG_SMALL( + "Multiband Compress or expand audio dynamic range."), + .query_formats = query_formats, + .priv_size = sizeof(MCompandContext), + .priv_class = &mcompand_class, + .uninit = uninit, + .inputs = mcompand_inputs, + .outputs = mcompand_outputs, +}; |
