diff --git a/Changelog b/Changelog index c2fd10f6f8..12fe77c708 100644 --- a/Changelog +++ b/Changelog @@ -9,6 +9,7 @@ version : - stereowiden filter - stereotools filter - rubberband filter +- tremolo filter version 2.8: diff --git a/doc/filters.texi b/doc/filters.texi index 88cb3ce863..5bbbaf0b78 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -2568,6 +2568,25 @@ slope Determine how steep is the filter's shelf transition. @end table +@section tremolo + +Sinusoidal amplitude modulation. + +The filter accepts the following options: + +@table @option +@item f +Modulation frequency in Hertz. Modulation frequencies in the subharmonic range +(20 Hz or lower) will result in a tremolo effect. +This filter may also be used as a ring modulator by specifying +a modulation frequency higher than 20 Hz. +Range is 0.1 - 20000.0. Default value is 5.0 Hz. + +@item d +Depth of modulation as a percentage. Range is 0.0 - 1.0. +Default value is 0.5. +@end table + @section volume Adjust the input audio volume. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 4bbe972950..8db5da9bc6 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -84,6 +84,7 @@ OBJS-$(CONFIG_SILENCEREMOVE_FILTER) += af_silenceremove.o OBJS-$(CONFIG_STEREOTOOLS_FILTER) += af_stereotools.o OBJS-$(CONFIG_STEREOWIDEN_FILTER) += af_stereowiden.o OBJS-$(CONFIG_TREBLE_FILTER) += af_biquads.o +OBJS-$(CONFIG_TREMOLO_FILTER) += af_tremolo.o generate_wave_table.o OBJS-$(CONFIG_VOLUME_FILTER) += af_volume.o OBJS-$(CONFIG_VOLUMEDETECT_FILTER) += af_volumedetect.o diff --git a/libavfilter/af_tremolo.c b/libavfilter/af_tremolo.c new file mode 100644 index 0000000000..633540167f --- /dev/null +++ b/libavfilter/af_tremolo.c @@ -0,0 +1,173 @@ +/* + * Copyright (c) 2015 Kyle Swanson . + * + * 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" +#include "generate_wave_table.h" + +typedef struct TremoloContext { + const AVClass *class; + double freq; + double depth; + double *wave_table; + int wave_table_index; + int sample_rate; +} TremoloContext; + +#define OFFSET(x) offsetof(TremoloContext, x) +#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption tremolo_options[] = { + { "f", "set frequency in hertz", OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl = 5.0}, 0.1, 20000.0, FLAGS }, + { "d", "set depth as percentage", OFFSET(depth), AV_OPT_TYPE_DOUBLE, {.dbl = 0.5}, 0.0, 1.0, FLAGS }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(tremolo); + +static double trem_env(AVFilterContext *ctx) +{ + TremoloContext *s = ctx->priv; + double env = s->wave_table[s->wave_table_index]; + s->wave_table_index++; + if (s->wave_table_index >= s->sample_rate / s->freq) + s->wave_table_index = 0; + return 1.0 - (s->depth * env); +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + AVFilterContext *ctx = inlink->dst; + AVFilterLink *outlink = ctx->outputs[0]; + const double *src = (const double *)in->data[0]; + const int channels = inlink->channels; + const int nb_samples = in->nb_samples; + AVFrame *out; + double *dst; + int n, c; + + 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 (n = 0; n < nb_samples; n++) { + const double env = trem_env(ctx); + + for (c = 0; c < channels; c++) + dst[c] = src[c] * env; + dst += channels; + src += 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) +{ + TremoloContext *s = ctx->priv; + av_freep(&s->wave_table); +} + +static int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + TremoloContext *s = ctx->priv; + + s->sample_rate = inlink->sample_rate; + s->wave_table = av_malloc_array(s->sample_rate / s->freq, sizeof(*s->wave_table)); + if (!s->wave_table) + return AVERROR(ENOMEM); + + ff_generate_wave_table(WAVE_SIN, AV_SAMPLE_FMT_DBL, s->wave_table, s->sample_rate / s->freq, 0.0, 1.0, 0.0); + s->wave_table_index = 0; + return 0; +} + +static const AVFilterPad avfilter_af_tremolo_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .config_props = config_input, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad avfilter_af_tremolo_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, + { NULL } +}; + +AVFilter ff_af_tremolo = { + .name = "tremolo", + .description = NULL_IF_CONFIG_SMALL("Apply tremolo effect."), + .priv_size = sizeof(TremoloContext), + .priv_class = &tremolo_class, + .uninit = uninit, + .query_formats = query_formats, + .inputs = avfilter_af_tremolo_inputs, + .outputs = avfilter_af_tremolo_outputs, +}; diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 3b3a49f2d9..292ecde289 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -106,6 +106,7 @@ void avfilter_register_all(void) REGISTER_FILTER(STEREOTOOLS, stereotools, af); REGISTER_FILTER(STEREOWIDEN, stereowiden, af); REGISTER_FILTER(TREBLE, treble, af); + REGISTER_FILTER(TREMOLO, tremolo, af); REGISTER_FILTER(VOLUME, volume, af); REGISTER_FILTER(VOLUMEDETECT, volumedetect, af); diff --git a/libavfilter/version.h b/libavfilter/version.h index 9d44fd0a10..96503770e1 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -30,7 +30,7 @@ #include "libavutil/version.h" #define LIBAVFILTER_VERSION_MAJOR 6 -#define LIBAVFILTER_VERSION_MINOR 6 +#define LIBAVFILTER_VERSION_MINOR 7 #define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \