diff options
| -rw-r--r-- | Changelog | 1 | ||||
| -rw-r--r-- | doc/filters.texi | 20 | ||||
| -rw-r--r-- | libavfilter/Makefile | 1 | ||||
| -rw-r--r-- | libavfilter/af_virtualbass.c | 183 | ||||
| -rw-r--r-- | libavfilter/allfilters.c | 1 | ||||
| -rw-r--r-- | libavfilter/version.h | 2 |
6 files changed, 207 insertions, 1 deletions
@@ -20,6 +20,7 @@ version 5.1: - tiltshelf audio filter - QOI image format support - ffprobe -o option +- virtualbass audio filter version 5.0: diff --git a/doc/filters.texi b/doc/filters.texi index d65e83d4d0..5abab5de18 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -6927,6 +6927,26 @@ Depth of modulation as a percentage. Range is 0.0 - 1.0. Default value is 0.5. @end table +@section virtualbass + +Apply audio Virtual Bass filter. + +This filter accepts stereo input and produce stereo with LFE (2.1) channels output. +The newly produced LFE channel have enhanced virtual bass originally obtained from both stereo channels. +This filter outputs front left and front right channels unchanged as available in stereo input. + +The filter accepts the following options: + +@table @option +@item cutoff +Set the virtual bass cutoff frequency. Default value is 250 Hz. +Allowed range is from 100 to 500 Hz. + +@item strength +Set the virtual bass strength. Allowed range is from 0.5 to 3. +Default value is 3. +@end table + @section volume Adjust the input audio volume. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index e0e4d0de2c..7ba1c8a861 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -164,6 +164,7 @@ OBJS-$(CONFIG_SURROUND_FILTER) += af_surround.o OBJS-$(CONFIG_TREBLE_FILTER) += af_biquads.o OBJS-$(CONFIG_TREMOLO_FILTER) += af_tremolo.o OBJS-$(CONFIG_VIBRATO_FILTER) += af_vibrato.o generate_wave_table.o +OBJS-$(CONFIG_VIRTUALBASS_FILTER) += af_virtualbass.o OBJS-$(CONFIG_VOLUME_FILTER) += af_volume.o OBJS-$(CONFIG_VOLUMEDETECT_FILTER) += af_volumedetect.o diff --git a/libavfilter/af_virtualbass.c b/libavfilter/af_virtualbass.c new file mode 100644 index 0000000000..950159096b --- /dev/null +++ b/libavfilter/af_virtualbass.c @@ -0,0 +1,183 @@ +/* + * Copyright (c) 2022 Paul B Mahol + * + * 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/channel_layout.h" +#include "libavutil/opt.h" +#include "audio.h" +#include "avfilter.h" +#include "filters.h" +#include "internal.h" + +#include <float.h> + +typedef struct AudioVirtualBassContext { + const AVClass *class; + + double cutoff; + double strength; + + double a[3], m[3], cf[2]; +} AudioVirtualBassContext; + +#define OFFSET(x) offsetof(AudioVirtualBassContext, x) +#define TFLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_RUNTIME_PARAM +#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption virtualbass_options[] = { + { "cutoff", "set virtual bass cutoff", OFFSET(cutoff), AV_OPT_TYPE_DOUBLE, {.dbl=250},100,500, FLAGS }, + { "strength", "set virtual bass strength", OFFSET(strength), AV_OPT_TYPE_DOUBLE, {.dbl=3}, 0.5, 3, TFLAGS }, + {NULL} +}; + +AVFILTER_DEFINE_CLASS(virtualbass); + +static int query_formats(AVFilterContext *ctx) +{ + AVFilterChannelLayouts *in_layout = NULL, *out_layout = NULL; + AVFilterFormats *formats = NULL; + int ret; + + if ((ret = ff_add_format (&formats, AV_SAMPLE_FMT_DBLP )) < 0 || + (ret = ff_set_common_formats (ctx, formats )) < 0 || + (ret = ff_add_channel_layout (&in_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO)) < 0 || + (ret = ff_channel_layouts_ref(in_layout, &ctx->inputs[0]->outcfg.channel_layouts)) < 0 || + (ret = ff_add_channel_layout (&out_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_2POINT1)) < 0 || + (ret = ff_channel_layouts_ref(out_layout, &ctx->outputs[0]->incfg.channel_layouts)) < 0) + return ret; + + return ff_set_common_all_samplerates(ctx); +} + +static int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + AudioVirtualBassContext *s = ctx->priv; + const double Q = 0.707; + double g, k; + + g = tan(M_PI * s->cutoff / inlink->sample_rate); + k = 1. / Q; + s->a[0] = 1. / (1. + g * (g + k)); + s->a[1] = g * s->a[0]; + s->a[2] = g * s->a[1]; + s->m[0] = 0.; + s->m[1] = 0.; + s->m[2] = 1.; + + return 0; +} + +#define SQR(x) ((x) * (x)) + +static double vb_fun(double x) +{ + double y = 2.5 * atan(0.9 * x) + 2.5 * sqrt(1. - SQR(0.9 * x)) - 2.5; + + return y < 0. ? sin(y) : y; +} + +static void vb_stereo(AVFilterContext *ctx, AVFrame *out, AVFrame *in) +{ + AudioVirtualBassContext *s = ctx->priv; + const double *lsrc = (const double *)in->extended_data[0]; + const double *rsrc = (const double *)in->extended_data[1]; + double *ldst = (double *)out->extended_data[0]; + double *rdst = (double *)out->extended_data[1]; + double *lfe = (double *)out->extended_data[2]; + const double st = M_PI / s->strength; + const double a0 = s->a[0]; + const double a1 = s->a[1]; + const double a2 = s->a[2]; + const double m0 = s->m[0]; + const double m1 = s->m[1]; + const double m2 = s->m[2]; + double b0 = s->cf[0]; + double b1 = s->cf[1]; + + memcpy(ldst, lsrc, in->nb_samples * sizeof(double)); + memcpy(rdst, rsrc, in->nb_samples * sizeof(double)); + + for (int n = 0; n < in->nb_samples; n++) { + const double center = (lsrc[n] + rsrc[n]) * 0.5; + const double v0 = center; + const double v3 = v0 - b1; + const double v1 = a0 * b0 + a1 * v3; + const double v2 = b1 + a1 * b0 + a2 * v3; + double b, vb; + + b0 = 2. * v1 - b0; + b1 = 2. * v2 - b1; + + b = m0 * v0 + m1 * v1 + m2 * v2; + vb = sin(vb_fun(b) * st); + + lfe[n] = vb; + } + + s->cf[0] = b0; + s->cf[1] = b1; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + AVFrame *out; + + out = ff_get_audio_buffer(outlink, in->nb_samples); + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + + vb_stereo(ctx, out, in); + + out->pts = in->pts; + av_frame_free(&in); + return ff_filter_frame(outlink, out); +} + +static const AVFilterPad inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .filter_frame = filter_frame, + .config_props = config_input, + }, +}; + +static const AVFilterPad outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, +}; + +const AVFilter ff_af_virtualbass = { + .name = "virtualbass", + .description = NULL_IF_CONFIG_SMALL("Audio Virtual Bass."), + .priv_size = sizeof(AudioVirtualBassContext), + .priv_class = &virtualbass_class, + FILTER_INPUTS(inputs), + FILTER_OUTPUTS(outputs), + FILTER_QUERY_FUNC(query_formats), + .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL, + .process_command = ff_filter_process_command, +}; diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 2f72477523..ec70feef11 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -153,6 +153,7 @@ extern const AVFilter ff_af_tiltshelf; extern const AVFilter ff_af_treble; extern const AVFilter ff_af_tremolo; extern const AVFilter ff_af_vibrato; +extern const AVFilter ff_af_virtualbass; extern const AVFilter ff_af_volume; extern const AVFilter ff_af_volumedetect; diff --git a/libavfilter/version.h b/libavfilter/version.h index 86b33c4174..814ab071da 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -31,7 +31,7 @@ #include "version_major.h" -#define LIBAVFILTER_VERSION_MINOR 40 +#define LIBAVFILTER_VERSION_MINOR 41 #define LIBAVFILTER_VERSION_MICRO 100 |