@@ -2093,6 +2093,28 @@ audio, the data is treated as if all the planes were concatenated.
A list of Adler-32 checksums for each data plane.
@end table
+@section asoftclip
+
+Apply audio soft clipping.
+
+This filter accepts the following options:
+
+@table @option
+@item type
+Set type of soft-clipping.
+
+It accepts the following values:
+@table @option
+@item tanh
+@item sin
+@item bdj
+@item atan
+@end table
+
+@item clip
+Set clipping limit value. Default is 1. Allowed range is @code{[0.01 - 1]}.
+@end table
+
@anchor{astats}
@section astats
@@ -80,6 +80,7 @@ OBJS-$(CONFIG_ASETRATE_FILTER) += af_asetrate.o
OBJS-$(CONFIG_ASETTB_FILTER) += settb.o
OBJS-$(CONFIG_ASHOWINFO_FILTER) += af_ashowinfo.o
OBJS-$(CONFIG_ASIDEDATA_FILTER) += f_sidedata.o
+OBJS-$(CONFIG_ASOFTCLIP_FILTER) += af_asoftclip.o
OBJS-$(CONFIG_ASPLIT_FILTER) += split.o
OBJS-$(CONFIG_ASTATS_FILTER) += af_astats.o
OBJS-$(CONFIG_ASTREAMSELECT_FILTER) += f_streamselect.o framesync.o
new file mode 100644
@@ -0,0 +1,206 @@
+/*
+ * Copyright (c) 2019 The FFmpeg Project
+ *
+ * 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 "avfilter.h"
+#include "audio.h"
+#include "formats.h"
+
+enum ASoftClipTypes {
+ ASC_TANH,
+ ASC_SIN,
+ ASC_BDJ,
+ ASC_ATAN,
+ NB_TYPES,
+};
+
+typedef struct ASoftClipContext {
+ const AVClass *class;
+
+ int type;
+ double clip;
+
+ void (*filter)(struct ASoftClipContext *s, void **dst, const void **src,
+ int nb_samples, int channels);
+} ASoftClipContext;
+
+#define OFFSET(x) offsetof(ASoftClipContext, x)
+#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption asoftclip_options[] = {
+ { "type", "set softclip type", OFFSET(type), AV_OPT_TYPE_INT, {.i64=0}, 0, NB_TYPES-1, A, "types" },
+ { "tanh", NULL, 0, AV_OPT_TYPE_CONST, {.i64=ASC_TANH}, 0, 0, A, "types" },
+ { "sin", NULL, 0, AV_OPT_TYPE_CONST, {.i64=ASC_SIN}, 0, 0, A, "types" },
+ { "bdj", NULL, 0, AV_OPT_TYPE_CONST, {.i64=ASC_BDJ}, 0, 0, A, "types" },
+ { "atan", NULL, 0, AV_OPT_TYPE_CONST, {.i64=ASC_ATAN}, 0, 0, A, "types" },
+ { "clip", "set softclip clip", OFFSET(clip), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.01, 1, A },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(asoftclip);
+
+static int query_formats(AVFilterContext *ctx)
+{
+ AVFilterFormats *formats = NULL;
+ AVFilterChannelLayouts *layouts = NULL;
+ static const enum AVSampleFormat sample_fmts[] = {
+ AV_SAMPLE_FMT_DBLP,
+ AV_SAMPLE_FMT_NONE
+ };
+ int 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;
+
+ 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_all_samplerates();
+ return ff_set_common_samplerates(ctx, formats);
+}
+
+#define SQR(x) ((x) * (x))
+
+static void filter_dblp(ASoftClipContext *s,
+ void **dptr, const void **sptr,
+ int nb_samples, int channels)
+{
+ double clip = s->clip;
+ int n, c;
+
+ for (c = 0; c < channels; c++) {
+ const double *src = sptr[c];
+ double *dst = dptr[c];
+
+ switch (s->type) {
+ case ASC_TANH:
+ for (n = 0; n < nb_samples; n++) {
+ double current = src[n];
+ double aclip = av_clipd(current, -clip, clip);
+ double sclip = current - aclip;
+
+ dst[n] = aclip + tanh(sclip / clip) * clip;
+ }
+ break;
+ case ASC_SIN:
+ for (n = 0; n < nb_samples; n++) {
+ double current = src[n];
+ double aclip = av_clipd(current, -clip, clip);
+ double sclip = current - aclip;
+
+ dst[n] = aclip + sin(sclip * M_PI_2) * clip;
+ }
+ break;
+ case ASC_BDJ:
+ for (n = 0; n < nb_samples; n++) {
+ double current = src[n];
+ double aclip = av_clipd(current, -clip, clip);
+ double sclip = current - aclip;
+
+ dst[n] = aclip + (sclip / (1. + SQR(sclip / clip)));
+ }
+ break;
+ case ASC_ATAN:
+ for (n = 0; n < nb_samples; n++) {
+ double current = src[n];
+ double aclip = av_clipd(current, -clip, clip);
+ double sclip = current - aclip;
+
+ dst[n] = aclip + 2. / M_PI * atan(sclip / 5.);
+ }
+ break;
+ }
+ }
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ASoftClipContext *s = ctx->priv;
+
+ s->filter = filter_dblp;
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ ASoftClipContext *s = ctx->priv;
+ AVFrame *out;
+
+ if (av_frame_is_writable(in)) {
+ out = in;
+ } else {
+ out = ff_get_audio_buffer(outlink, in->nb_samples);
+ if (!out) {
+ av_frame_free(&in);
+ return AVERROR(ENOMEM);
+ }
+ av_frame_copy_props(out, in);
+ }
+
+ s->filter(s, (void **)out->extended_data, (const void **)in->extended_data,
+ in->nb_samples, in->channels);
+
+ if (out != in)
+ 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,
+ },
+ { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ },
+ { NULL }
+};
+
+AVFilter ff_af_asoftclip = {
+ .name = "asoftclip",
+ .description = NULL_IF_CONFIG_SMALL("Audio Soft Clipper."),
+ .query_formats = query_formats,
+ .priv_size = sizeof(ASoftClipContext),
+ .priv_class = &asoftclip_class,
+ .inputs = inputs,
+ .outputs = outputs,
+};
@@ -72,6 +72,7 @@ extern AVFilter ff_af_asetrate;
extern AVFilter ff_af_asettb;
extern AVFilter ff_af_ashowinfo;
extern AVFilter ff_af_asidedata;
+extern AVFilter ff_af_asoftclip;
extern AVFilter ff_af_asplit;
extern AVFilter ff_af_astats;
extern AVFilter ff_af_astreamselect;
Signed-off-by: Paul B Mahol <onemda@gmail.com> --- doc/filters.texi | 22 ++++ libavfilter/Makefile | 1 + libavfilter/af_asoftclip.c | 206 +++++++++++++++++++++++++++++++++++++ libavfilter/allfilters.c | 1 + 4 files changed, 230 insertions(+) create mode 100644 libavfilter/af_asoftclip.c