| /* |
| * Copyright (c) Markus Schmidt and Christian Holschuh |
| * |
| * 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 |
| */ |
| |
| #include "libavutil/opt.h" |
| #include "avfilter.h" |
| #include "internal.h" |
| #include "audio.h" |
| |
| typedef struct ChannelParams { |
| double blend_old, drive_old; |
| double rdrive, rbdr, kpa, kpb, kna, knb, ap, |
| an, imr, kc, srct, sq, pwrq; |
| double prev_med, prev_out; |
| |
| double hp[5], lp[5]; |
| double hw[4][2], lw[2][2]; |
| } ChannelParams; |
| |
| typedef struct AExciterContext { |
| const AVClass *class; |
| |
| double level_in; |
| double level_out; |
| double amount; |
| double drive; |
| double blend; |
| double freq; |
| double ceil; |
| int listen; |
| |
| ChannelParams *cp; |
| } AExciterContext; |
| |
| #define OFFSET(x) offsetof(AExciterContext, x) |
| #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM |
| |
| static const AVOption aexciter_options[] = { |
| { "level_in", "set level in", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, A }, |
| { "level_out", "set level out", OFFSET(level_out), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, A }, |
| { "amount", "set amount", OFFSET(amount), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, A }, |
| { "drive", "set harmonics", OFFSET(drive), AV_OPT_TYPE_DOUBLE, {.dbl=8.5}, 0.1, 10, A }, |
| { "blend", "set blend harmonics", OFFSET(blend), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -10, 10, A }, |
| { "freq", "set scope", OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl=7500}, 2000, 12000, A }, |
| { "ceil", "set ceiling", OFFSET(ceil), AV_OPT_TYPE_DOUBLE, {.dbl=9999}, 9999, 20000, A }, |
| { "listen", "enable listen mode", OFFSET(listen), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, A }, |
| { NULL } |
| }; |
| |
| AVFILTER_DEFINE_CLASS(aexciter); |
| |
| static inline double M(double x) |
| { |
| return (fabs(x) > 0.00000001) ? x : 0.0; |
| } |
| |
| static inline double D(double x) |
| { |
| x = fabs(x); |
| |
| return (x > 0.00000001) ? sqrt(x) : 0.0; |
| } |
| |
| static void set_params(ChannelParams *p, |
| double blend, double drive, |
| double srate, double freq, |
| double ceil) |
| { |
| double a0, a1, a2, b0, b1, b2, w0, alpha; |
| |
| p->rdrive = 12.0 / drive; |
| p->rbdr = p->rdrive / (10.5 - blend) * 780.0 / 33.0; |
| p->kpa = D(2.0 * (p->rdrive*p->rdrive) - 1.0) + 1.0; |
| p->kpb = (2.0 - p->kpa) / 2.0; |
| p->ap = ((p->rdrive*p->rdrive) - p->kpa + 1.0) / 2.0; |
| p->kc = p->kpa / D(2.0 * D(2.0 * (p->rdrive*p->rdrive) - 1.0) - 2.0 * p->rdrive*p->rdrive); |
| |
| p->srct = (0.1 * srate) / (0.1 * srate + 1.0); |
| p->sq = p->kc*p->kc + 1.0; |
| p->knb = -1.0 * p->rbdr / D(p->sq); |
| p->kna = 2.0 * p->kc * p->rbdr / D(p->sq); |
| p->an = p->rbdr*p->rbdr / p->sq; |
| p->imr = 2.0 * p->knb + D(2.0 * p->kna + 4.0 * p->an - 1.0); |
| p->pwrq = 2.0 / (p->imr + 1.0); |
| |
| w0 = 2 * M_PI * freq / srate; |
| alpha = sin(w0) / (2. * 0.707); |
| a0 = 1 + alpha; |
| a1 = -2 * cos(w0); |
| a2 = 1 - alpha; |
| b0 = (1 + cos(w0)) / 2; |
| b1 = -(1 + cos(w0)); |
| b2 = (1 + cos(w0)) / 2; |
| |
| p->hp[0] =-a1 / a0; |
| p->hp[1] =-a2 / a0; |
| p->hp[2] = b0 / a0; |
| p->hp[3] = b1 / a0; |
| p->hp[4] = b2 / a0; |
| |
| w0 = 2 * M_PI * ceil / srate; |
| alpha = sin(w0) / (2. * 0.707); |
| a0 = 1 + alpha; |
| a1 = -2 * cos(w0); |
| a2 = 1 - alpha; |
| b0 = (1 - cos(w0)) / 2; |
| b1 = 1 - cos(w0); |
| b2 = (1 - cos(w0)) / 2; |
| |
| p->lp[0] =-a1 / a0; |
| p->lp[1] =-a2 / a0; |
| p->lp[2] = b0 / a0; |
| p->lp[3] = b1 / a0; |
| p->lp[4] = b2 / a0; |
| } |
| |
| static double bprocess(double in, const double *const c, |
| double *w1, double *w2) |
| { |
| double out = c[2] * in + *w1; |
| |
| *w1 = c[3] * in + *w2 + c[0] * out; |
| *w2 = c[4] * in + c[1] * out; |
| |
| return out; |
| } |
| |
| static double distortion_process(AExciterContext *s, ChannelParams *p, double in) |
| { |
| double proc = in, med; |
| |
| proc = bprocess(proc, p->hp, &p->hw[0][0], &p->hw[0][1]); |
| proc = bprocess(proc, p->hp, &p->hw[1][0], &p->hw[1][1]); |
| |
| if (proc >= 0.0) { |
| med = (D(p->ap + proc * (p->kpa - proc)) + p->kpb) * p->pwrq; |
| } else { |
| med = (D(p->an - proc * (p->kna + proc)) + p->knb) * p->pwrq * -1.0; |
| } |
| |
| proc = p->srct * (med - p->prev_med + p->prev_out); |
| p->prev_med = M(med); |
| p->prev_out = M(proc); |
| |
| proc = bprocess(proc, p->hp, &p->hw[2][0], &p->hw[2][1]); |
| proc = bprocess(proc, p->hp, &p->hw[3][0], &p->hw[3][1]); |
| |
| if (s->ceil >= 10000.) { |
| proc = bprocess(proc, p->lp, &p->lw[0][0], &p->lw[0][1]); |
| proc = bprocess(proc, p->lp, &p->lw[1][0], &p->lw[1][1]); |
| } |
| |
| return proc; |
| } |
| |
| static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AExciterContext *s = ctx->priv; |
| AVFilterLink *outlink = ctx->outputs[0]; |
| AVFrame *out; |
| const double *src = (const double *)in->data[0]; |
| const double level_in = s->level_in; |
| const double level_out = s->level_out; |
| const double amount = s->amount; |
| const double listen = 1.0 - s->listen; |
| double *dst; |
| |
| if (av_frame_is_writable(in)) { |
| out = in; |
| } else { |
| out = ff_get_audio_buffer(inlink, in->nb_samples); |
| if (!out) { |
| av_frame_free(&in); |
| return AVERROR(ENOMEM); |
| } |
| av_frame_copy_props(out, in); |
| } |
| |
| dst = (double *)out->data[0]; |
| for (int n = 0; n < in->nb_samples; n++) { |
| for (int c = 0; c < inlink->channels; c++) { |
| double sample = src[c] * level_in; |
| |
| sample = distortion_process(s, &s->cp[c], sample); |
| sample = sample * amount + listen * src[c]; |
| |
| sample *= level_out; |
| if (ctx->is_disabled) |
| dst[c] = src[c]; |
| else |
| dst[c] = sample; |
| } |
| |
| src += inlink->channels; |
| dst += inlink->channels; |
| } |
| |
| if (in != out) |
| av_frame_free(&in); |
| |
| return ff_filter_frame(outlink, out); |
| } |
| |
| static int query_formats(AVFilterContext *ctx) |
| { |
| AVFilterFormats *formats; |
| AVFilterChannelLayouts *layouts; |
| static const enum AVSampleFormat sample_fmts[] = { |
| AV_SAMPLE_FMT_DBL, |
| 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 av_cold void uninit(AVFilterContext *ctx) |
| { |
| AExciterContext *s = ctx->priv; |
| |
| av_freep(&s->cp); |
| } |
| |
| static int config_input(AVFilterLink *inlink) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AExciterContext *s = ctx->priv; |
| |
| if (!s->cp) |
| s->cp = av_calloc(inlink->channels, sizeof(*s->cp)); |
| if (!s->cp) |
| return AVERROR(ENOMEM); |
| |
| for (int i = 0; i < inlink->channels; i++) |
| set_params(&s->cp[i], s->blend, s->drive, inlink->sample_rate, |
| s->freq, s->ceil); |
| |
| return 0; |
| } |
| |
| static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, |
| char *res, int res_len, int flags) |
| { |
| AVFilterLink *inlink = ctx->inputs[0]; |
| int ret; |
| |
| ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags); |
| if (ret < 0) |
| return ret; |
| |
| return config_input(inlink); |
| } |
| |
| static const AVFilterPad avfilter_af_aexciter_inputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .config_props = config_input, |
| .filter_frame = filter_frame, |
| }, |
| { NULL } |
| }; |
| |
| static const AVFilterPad avfilter_af_aexciter_outputs[] = { |
| { |
| .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| }, |
| { NULL } |
| }; |
| |
| AVFilter ff_af_aexciter = { |
| .name = "aexciter", |
| .description = NULL_IF_CONFIG_SMALL("Enhance high frequency part of audio."), |
| .priv_size = sizeof(AExciterContext), |
| .priv_class = &aexciter_class, |
| .uninit = uninit, |
| .query_formats = query_formats, |
| .inputs = avfilter_af_aexciter_inputs, |
| .outputs = avfilter_af_aexciter_outputs, |
| .process_command = process_command, |
| .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL, |
| }; |