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- /*
- * 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
- * Crossover filter
- *
- * Split an audio stream into several bands.
- */
-
- #include "libavutil/attributes.h"
- #include "libavutil/avstring.h"
- #include "libavutil/channel_layout.h"
- #include "libavutil/eval.h"
- #include "libavutil/float_dsp.h"
- #include "libavutil/internal.h"
- #include "libavutil/opt.h"
-
- #include "audio.h"
- #include "avfilter.h"
- #include "formats.h"
- #include "internal.h"
-
- #define MAX_SPLITS 16
- #define MAX_BANDS MAX_SPLITS + 1
-
- #define B0 0
- #define B1 1
- #define B2 2
- #define A1 3
- #define A2 4
-
- typedef struct BiquadCoeffs {
- double cd[5];
- float cf[5];
- } BiquadCoeffs;
-
- typedef struct AudioCrossoverContext {
- const AVClass *class;
-
- char *splits_str;
- char *gains_str;
- int order_opt;
- float level_in;
-
- int order;
- int filter_count;
- int first_order;
- int ap_filter_count;
- int nb_splits;
- float splits[MAX_SPLITS];
-
- float gains[MAX_BANDS];
-
- BiquadCoeffs lp[MAX_BANDS][20];
- BiquadCoeffs hp[MAX_BANDS][20];
- BiquadCoeffs ap[MAX_BANDS][20];
-
- AVFrame *xover;
-
- AVFrame *input_frame;
- AVFrame *frames[MAX_BANDS];
-
- int (*filter_channels)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
-
- AVFloatDSPContext *fdsp;
- } AudioCrossoverContext;
-
- #define OFFSET(x) offsetof(AudioCrossoverContext, x)
- #define AF AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
-
- static const AVOption acrossover_options[] = {
- { "split", "set split frequencies", OFFSET(splits_str), AV_OPT_TYPE_STRING, {.str="500"}, 0, 0, AF },
- { "order", "set filter order", OFFSET(order_opt), AV_OPT_TYPE_INT, {.i64=1}, 0, 9, AF, "m" },
- { "2nd", "2nd order (12 dB/8ve)", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, AF, "m" },
- { "4th", "4th order (24 dB/8ve)", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, AF, "m" },
- { "6th", "6th order (36 dB/8ve)", 0, AV_OPT_TYPE_CONST, {.i64=2}, 0, 0, AF, "m" },
- { "8th", "8th order (48 dB/8ve)", 0, AV_OPT_TYPE_CONST, {.i64=3}, 0, 0, AF, "m" },
- { "10th", "10th order (60 dB/8ve)",0, AV_OPT_TYPE_CONST, {.i64=4}, 0, 0, AF, "m" },
- { "12th", "12th order (72 dB/8ve)",0, AV_OPT_TYPE_CONST, {.i64=5}, 0, 0, AF, "m" },
- { "14th", "14th order (84 dB/8ve)",0, AV_OPT_TYPE_CONST, {.i64=6}, 0, 0, AF, "m" },
- { "16th", "16th order (96 dB/8ve)",0, AV_OPT_TYPE_CONST, {.i64=7}, 0, 0, AF, "m" },
- { "18th", "18th order (108 dB/8ve)",0, AV_OPT_TYPE_CONST, {.i64=8}, 0, 0, AF, "m" },
- { "20th", "20th order (120 dB/8ve)",0, AV_OPT_TYPE_CONST, {.i64=9}, 0, 0, AF, "m" },
- { "level", "set input gain", OFFSET(level_in), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 1, AF },
- { "gain", "set output bands gain", OFFSET(gains_str), AV_OPT_TYPE_STRING, {.str="1.f"}, 0, 0, AF },
- { NULL }
- };
-
- AVFILTER_DEFINE_CLASS(acrossover);
-
- static int parse_gains(AVFilterContext *ctx)
- {
- AudioCrossoverContext *s = ctx->priv;
- char *p, *arg, *saveptr = NULL;
- int i, ret = 0;
-
- saveptr = NULL;
- p = s->gains_str;
- for (i = 0; i < MAX_BANDS; i++) {
- float gain;
- char c[3] = { 0 };
-
- if (!(arg = av_strtok(p, " |", &saveptr)))
- break;
-
- p = NULL;
-
- if (av_sscanf(arg, "%f%2s", &gain, c) < 1) {
- av_log(ctx, AV_LOG_ERROR, "Invalid syntax for gain[%d].\n", i);
- ret = AVERROR(EINVAL);
- break;
- }
-
- if (c[0] == 'd' && c[1] == 'B')
- s->gains[i] = expf(gain * M_LN10 / 20.f);
- else
- s->gains[i] = gain;
- }
-
- for (; i < MAX_BANDS; i++)
- s->gains[i] = 1.f;
-
- return ret;
- }
-
- static av_cold int init(AVFilterContext *ctx)
- {
- AudioCrossoverContext *s = ctx->priv;
- char *p, *arg, *saveptr = NULL;
- int i, ret = 0;
-
- s->fdsp = avpriv_float_dsp_alloc(0);
- if (!s->fdsp)
- return AVERROR(ENOMEM);
-
- p = s->splits_str;
- for (i = 0; i < MAX_SPLITS; i++) {
- float freq;
-
- if (!(arg = av_strtok(p, " |", &saveptr)))
- break;
-
- p = NULL;
-
- if (av_sscanf(arg, "%f", &freq) != 1) {
- av_log(ctx, AV_LOG_ERROR, "Invalid syntax for frequency[%d].\n", i);
- return AVERROR(EINVAL);
- }
- if (freq <= 0) {
- av_log(ctx, AV_LOG_ERROR, "Frequency %f must be positive number.\n", freq);
- return AVERROR(EINVAL);
- }
-
- if (i > 0 && freq <= s->splits[i-1]) {
- av_log(ctx, AV_LOG_ERROR, "Frequency %f must be in increasing order.\n", freq);
- return AVERROR(EINVAL);
- }
-
- s->splits[i] = freq;
- }
-
- s->nb_splits = i;
-
- ret = parse_gains(ctx);
- if (ret < 0)
- return ret;
-
- for (i = 0; i <= s->nb_splits; i++) {
- AVFilterPad pad = { 0 };
- char *name;
-
- pad.type = AVMEDIA_TYPE_AUDIO;
- name = av_asprintf("out%d", ctx->nb_outputs);
- if (!name)
- return AVERROR(ENOMEM);
- pad.name = name;
-
- if ((ret = ff_insert_outpad(ctx, i, &pad)) < 0) {
- av_freep(&pad.name);
- return ret;
- }
- }
-
- return ret;
- }
-
- static void set_lp(BiquadCoeffs *b, double fc, double q, double sr)
- {
- double omega = 2. * M_PI * fc / sr;
- double cosine = cos(omega);
- double alpha = sin(omega) / (2. * q);
-
- double b0 = (1. - cosine) / 2.;
- double b1 = 1. - cosine;
- double b2 = (1. - cosine) / 2.;
- double a0 = 1. + alpha;
- double a1 = -2. * cosine;
- double a2 = 1. - alpha;
-
- b->cd[B0] = b0 / a0;
- b->cd[B1] = b1 / a0;
- b->cd[B2] = b2 / a0;
- b->cd[A1] = -a1 / a0;
- b->cd[A2] = -a2 / a0;
-
- b->cf[B0] = b->cd[B0];
- b->cf[B1] = b->cd[B1];
- b->cf[B2] = b->cd[B2];
- b->cf[A1] = b->cd[A1];
- b->cf[A2] = b->cd[A2];
- }
-
- static void set_hp(BiquadCoeffs *b, double fc, double q, double sr)
- {
- double omega = 2. * M_PI * fc / sr;
- double cosine = cos(omega);
- double alpha = sin(omega) / (2. * q);
-
- double b0 = (1. + cosine) / 2.;
- double b1 = -1. - cosine;
- double b2 = (1. + cosine) / 2.;
- double a0 = 1. + alpha;
- double a1 = -2. * cosine;
- double a2 = 1. - alpha;
-
- b->cd[B0] = b0 / a0;
- b->cd[B1] = b1 / a0;
- b->cd[B2] = b2 / a0;
- b->cd[A1] = -a1 / a0;
- b->cd[A2] = -a2 / a0;
-
- b->cf[B0] = b->cd[B0];
- b->cf[B1] = b->cd[B1];
- b->cf[B2] = b->cd[B2];
- b->cf[A1] = b->cd[A1];
- b->cf[A2] = b->cd[A2];
- }
-
- static void set_ap(BiquadCoeffs *b, double fc, double q, double sr)
- {
- double omega = 2. * M_PI * fc / sr;
- double cosine = cos(omega);
- double alpha = sin(omega) / (2. * q);
-
- double a0 = 1. + alpha;
- double a1 = -2. * cosine;
- double a2 = 1. - alpha;
- double b0 = a2;
- double b1 = a1;
- double b2 = a0;
-
- b->cd[B0] = b0 / a0;
- b->cd[B1] = b1 / a0;
- b->cd[B2] = b2 / a0;
- b->cd[A1] = -a1 / a0;
- b->cd[A2] = -a2 / a0;
-
- b->cf[B0] = b->cd[B0];
- b->cf[B1] = b->cd[B1];
- b->cf[B2] = b->cd[B2];
- b->cf[A1] = b->cd[A1];
- b->cf[A2] = b->cd[A2];
- }
-
- static void set_ap1(BiquadCoeffs *b, double fc, double sr)
- {
- double omega = 2. * M_PI * fc / sr;
-
- b->cd[A1] = exp(-omega);
- b->cd[A2] = 0.;
- b->cd[B0] = -b->cd[A1];
- b->cd[B1] = 1.;
- b->cd[B2] = 0.;
-
- b->cf[B0] = b->cd[B0];
- b->cf[B1] = b->cd[B1];
- b->cf[B2] = b->cd[B2];
- b->cf[A1] = b->cd[A1];
- b->cf[A2] = b->cd[A2];
- }
-
- static void calc_q_factors(int order, double *q)
- {
- double n = order / 2.;
-
- for (int i = 0; i < n / 2; i++)
- q[i] = 1. / (-2. * cos(M_PI * (2. * (i + 1) + n - 1.) / (2. * n)));
- }
-
- static int query_formats(AVFilterContext *ctx)
- {
- AVFilterFormats *formats;
- AVFilterChannelLayouts *layouts;
- static const enum AVSampleFormat sample_fmts[] = {
- AV_SAMPLE_FMT_FLTP, 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);
- }
-
- #define BIQUAD_PROCESS(name, type) \
- static void biquad_process_## name(const type *const c, \
- type *b, \
- type *dst, const type *src, \
- int nb_samples) \
- { \
- const type b0 = c[B0]; \
- const type b1 = c[B1]; \
- const type b2 = c[B2]; \
- const type a1 = c[A1]; \
- const type a2 = c[A2]; \
- type z1 = b[0]; \
- type z2 = b[1]; \
- \
- for (int n = 0; n + 1 < nb_samples; n++) { \
- type in = src[n]; \
- type out; \
- \
- out = in * b0 + z1; \
- z1 = b1 * in + z2 + a1 * out; \
- z2 = b2 * in + a2 * out; \
- dst[n] = out; \
- \
- n++; \
- in = src[n]; \
- out = in * b0 + z1; \
- z1 = b1 * in + z2 + a1 * out; \
- z2 = b2 * in + a2 * out; \
- dst[n] = out; \
- } \
- \
- if (nb_samples & 1) { \
- const int n = nb_samples - 1; \
- const type in = src[n]; \
- type out; \
- \
- out = in * b0 + z1; \
- z1 = b1 * in + z2 + a1 * out; \
- z2 = b2 * in + a2 * out; \
- dst[n] = out; \
- } \
- \
- b[0] = z1; \
- b[1] = z2; \
- }
-
- BIQUAD_PROCESS(fltp, float)
- BIQUAD_PROCESS(dblp, double)
-
- #define XOVER_PROCESS(name, type, one, ff) \
- static int filter_channels_## name(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) \
- { \
- AudioCrossoverContext *s = ctx->priv; \
- AVFrame *in = s->input_frame; \
- AVFrame **frames = s->frames; \
- const int start = (in->channels * jobnr) / nb_jobs; \
- const int end = (in->channels * (jobnr+1)) / nb_jobs; \
- const int nb_samples = in->nb_samples; \
- const int nb_outs = ctx->nb_outputs; \
- const int first_order = s->first_order; \
- \
- for (int ch = start; ch < end; ch++) { \
- const type *src = (const type *)in->extended_data[ch]; \
- type *xover = (type *)s->xover->extended_data[ch]; \
- \
- s->fdsp->vector_## ff ##mul_scalar((type *)frames[0]->extended_data[ch], src, \
- s->level_in, FFALIGN(nb_samples, sizeof(type))); \
- \
- for (int band = 0; band < nb_outs; band++) { \
- for (int f = 0; band + 1 < nb_outs && f < s->filter_count; f++) { \
- const type *prv = (const type *)frames[band]->extended_data[ch]; \
- type *dst = (type *)frames[band + 1]->extended_data[ch]; \
- const type *hsrc = f == 0 ? prv : dst; \
- type *hp = xover + nb_outs * 20 + band * 20 + f * 2; \
- const type *const hpc = (type *)&s->hp[band][f].c ## ff; \
- \
- biquad_process_## name(hpc, hp, dst, hsrc, nb_samples); \
- } \
- \
- for (int f = 0; band + 1 < nb_outs && f < s->filter_count; f++) { \
- type *dst = (type *)frames[band]->extended_data[ch]; \
- const type *lsrc = dst; \
- type *lp = xover + band * 20 + f * 2; \
- const type *const lpc = (type *)&s->lp[band][f].c ## ff; \
- \
- biquad_process_## name(lpc, lp, dst, lsrc, nb_samples); \
- } \
- \
- for (int aband = band + 1; aband + 1 < nb_outs; aband++) { \
- if (first_order) { \
- const type *asrc = (const type *)frames[band]->extended_data[ch]; \
- type *dst = (type *)frames[band]->extended_data[ch]; \
- type *ap = xover + nb_outs * 40 + (aband * nb_outs + band) * 20; \
- const type *const apc = (type *)&s->ap[aband][0].c ## ff; \
- \
- biquad_process_## name(apc, ap, dst, asrc, nb_samples); \
- } \
- \
- for (int f = first_order; f < s->ap_filter_count; f++) { \
- const type *asrc = (const type *)frames[band]->extended_data[ch]; \
- type *dst = (type *)frames[band]->extended_data[ch]; \
- type *ap = xover + nb_outs * 40 + (aband * nb_outs + band) * 20 + f * 2;\
- const type *const apc = (type *)&s->ap[aband][f].c ## ff; \
- \
- biquad_process_## name(apc, ap, dst, asrc, nb_samples); \
- } \
- } \
- } \
- \
- for (int band = 0; band < nb_outs; band++) { \
- const type gain = s->gains[band] * ((band & 1 && first_order) ? -one : one); \
- type *dst = (type *)frames[band]->extended_data[ch]; \
- \
- s->fdsp->vector_## ff ##mul_scalar(dst, dst, gain, \
- FFALIGN(nb_samples, sizeof(type))); \
- } \
- } \
- \
- return 0; \
- }
-
- XOVER_PROCESS(fltp, float, 1.f, f)
- XOVER_PROCESS(dblp, double, 1.0, d)
-
- static int config_input(AVFilterLink *inlink)
- {
- AVFilterContext *ctx = inlink->dst;
- AudioCrossoverContext *s = ctx->priv;
- int sample_rate = inlink->sample_rate;
- double q[16];
-
- s->order = (s->order_opt + 1) * 2;
- s->filter_count = s->order / 2;
- s->first_order = s->filter_count & 1;
- s->ap_filter_count = s->filter_count / 2 + s->first_order;
- calc_q_factors(s->order, q);
-
- for (int band = 0; band <= s->nb_splits; band++) {
- if (s->first_order) {
- set_lp(&s->lp[band][0], s->splits[band], 0.5, sample_rate);
- set_hp(&s->hp[band][0], s->splits[band], 0.5, sample_rate);
- }
-
- for (int n = s->first_order; n < s->filter_count; n++) {
- const int idx = s->filter_count / 2 - ((n + s->first_order) / 2 - s->first_order) - 1;
-
- set_lp(&s->lp[band][n], s->splits[band], q[idx], sample_rate);
- set_hp(&s->hp[band][n], s->splits[band], q[idx], sample_rate);
- }
-
- if (s->first_order)
- set_ap1(&s->ap[band][0], s->splits[band], sample_rate);
-
- for (int n = s->first_order; n < s->ap_filter_count; n++) {
- const int idx = (s->filter_count / 2 - ((n * 2 + s->first_order) / 2 - s->first_order) - 1);
-
- set_ap(&s->ap[band][n], s->splits[band], q[idx], sample_rate);
- }
- }
-
- switch (inlink->format) {
- case AV_SAMPLE_FMT_FLTP: s->filter_channels = filter_channels_fltp; break;
- case AV_SAMPLE_FMT_DBLP: s->filter_channels = filter_channels_dblp; break;
- }
-
- s->xover = ff_get_audio_buffer(inlink, 2 * (ctx->nb_outputs * 10 + ctx->nb_outputs * 10 +
- ctx->nb_outputs * ctx->nb_outputs * 10));
- if (!s->xover)
- return AVERROR(ENOMEM);
-
- return 0;
- }
-
- static int filter_frame(AVFilterLink *inlink, AVFrame *in)
- {
- AVFilterContext *ctx = inlink->dst;
- AudioCrossoverContext *s = ctx->priv;
- AVFrame **frames = s->frames;
- int i, ret = 0;
-
- for (i = 0; i < ctx->nb_outputs; i++) {
- frames[i] = ff_get_audio_buffer(ctx->outputs[i], in->nb_samples);
-
- if (!frames[i]) {
- ret = AVERROR(ENOMEM);
- break;
- }
-
- frames[i]->pts = in->pts;
- }
-
- if (ret < 0)
- goto fail;
-
- s->input_frame = in;
- ctx->internal->execute(ctx, s->filter_channels, NULL, NULL, FFMIN(inlink->channels,
- ff_filter_get_nb_threads(ctx)));
-
- for (i = 0; i < ctx->nb_outputs; i++) {
- ret = ff_filter_frame(ctx->outputs[i], frames[i]);
- frames[i] = NULL;
- if (ret < 0)
- break;
- }
-
- fail:
- for (i = 0; i < ctx->nb_outputs; i++)
- av_frame_free(&frames[i]);
- av_frame_free(&in);
- s->input_frame = NULL;
-
- return ret;
- }
-
- static av_cold void uninit(AVFilterContext *ctx)
- {
- AudioCrossoverContext *s = ctx->priv;
- int i;
-
- av_freep(&s->fdsp);
- av_frame_free(&s->xover);
-
- for (i = 0; i < ctx->nb_outputs; i++)
- av_freep(&ctx->output_pads[i].name);
- }
-
- static const AVFilterPad inputs[] = {
- {
- .name = "default",
- .type = AVMEDIA_TYPE_AUDIO,
- .filter_frame = filter_frame,
- .config_props = config_input,
- },
- { NULL }
- };
-
- AVFilter ff_af_acrossover = {
- .name = "acrossover",
- .description = NULL_IF_CONFIG_SMALL("Split audio into per-bands streams."),
- .priv_size = sizeof(AudioCrossoverContext),
- .priv_class = &acrossover_class,
- .init = init,
- .uninit = uninit,
- .query_formats = query_formats,
- .inputs = inputs,
- .outputs = NULL,
- .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS |
- AVFILTER_FLAG_SLICE_THREADS,
- };
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