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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00

avfilter: add anlms filter

This commit is contained in:
Paul B Mahol 2019-10-03 18:09:59 +02:00
parent a27c0781dd
commit e37edc70bd
6 changed files with 384 additions and 1 deletions

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@ -14,6 +14,7 @@ version <next>:
- sierpinski video source
- scroll video filter
- photosensitivity filter
- anlms filter
version 4.2:

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@ -1814,6 +1814,58 @@ Change output mode.
Syntax for the command is : "i", "o" or "n" string.
@end table
@section anlms
Apply Normalized Least-Mean-Squares algorithm to the first audio stream using the second audio stream.
This adaptive filter is used to mimic a desired filter by finding the filter coefficients that
relate to producing the least mean square of the error signal (difference between the desired,
2nd input audio stream and the actual signal, the 1st input audio stream).
A description of the accepted options follows.
@table @option
@item order
Set filter order.
@item mu
Set filter mu.
@item eps
Set the filter eps.
@item leakage
Set the filter leakage.
@item out_mode
It accepts the following values:
@table @option
@item i
Pass the 1st input.
@item d
Pass the 2nd input.
@item o
Pass filtered samples.
@item n
Pass difference between desired and filtered samples.
Default value is @var{o}.
@end table
@end table
@subsection Examples
@itemize
@item
One of many usages of this filter is noise reduction, input audio is filtered
with same samples that are delayed by fixed ammount, one such example for stereo audio is:
@example
asplit[a][b],[a]adelay=32S|32S[a],[b][a]anlms=order=128:leakage=0.0005:mu=.5:out_mode=o
@end example
@end itemize
@section anull
Pass the audio source unchanged to the output.

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@ -63,6 +63,7 @@ OBJS-$(CONFIG_AMIX_FILTER) += af_amix.o
OBJS-$(CONFIG_AMULTIPLY_FILTER) += af_amultiply.o
OBJS-$(CONFIG_ANEQUALIZER_FILTER) += af_anequalizer.o
OBJS-$(CONFIG_ANLMDN_FILTER) += af_anlmdn.o
OBJS-$(CONFIG_ANLMS_FILTER) += af_anlms.o
OBJS-$(CONFIG_ANULL_FILTER) += af_anull.o
OBJS-$(CONFIG_APAD_FILTER) += af_apad.o
OBJS-$(CONFIG_APERMS_FILTER) += f_perms.o

328
libavfilter/af_anlms.c Normal file
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@ -0,0 +1,328 @@
/*
* Copyright (c) 2019 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/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/common.h"
#include "libavutil/float_dsp.h"
#include "libavutil/opt.h"
#include "audio.h"
#include "avfilter.h"
#include "formats.h"
#include "filters.h"
#include "internal.h"
enum OutModes {
IN_MODE,
DESIRED_MODE,
OUT_MODE,
NOISE_MODE,
NB_OMODES
};
typedef struct AudioNLMSContext {
const AVClass *class;
int order;
float mu;
float eps;
float leakage;
int output_mode;
int kernel_size;
AVFrame *offset;
AVFrame *delay;
AVFrame *coeffs;
AVFrame *tmp;
AVFrame *frame[2];
AVFloatDSPContext *fdsp;
} AudioNLMSContext;
#define OFFSET(x) offsetof(AudioNLMSContext, x)
#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption anlms_options[] = {
{ "order", "set the filter order", OFFSET(order), AV_OPT_TYPE_INT, {.i64=256}, 1, INT16_MAX, A },
{ "mu", "set the filter mu", OFFSET(mu), AV_OPT_TYPE_FLOAT, {.dbl=0.75}, 0, 1, A },
{ "eps", "set the filter eps", OFFSET(eps), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 1, A },
{ "leakage", "set the filter leakage", OFFSET(leakage), AV_OPT_TYPE_FLOAT, {.dbl=0}, 0, 1, A },
{ "out_mode", "set output mode", OFFSET(output_mode), AV_OPT_TYPE_INT, {.i64=OUT_MODE}, 0, NB_OMODES-1, A, "mode" },
{ "i", "input", 0, AV_OPT_TYPE_CONST, {.i64=IN_MODE}, 0, 0, A, "mode" },
{ "d", "desired", 0, AV_OPT_TYPE_CONST, {.i64=DESIRED_MODE}, 0, 0, A, "mode" },
{ "o", "output", 0, AV_OPT_TYPE_CONST, {.i64=OUT_MODE}, 0, 0, A, "mode" },
{ "n", "noise", 0, AV_OPT_TYPE_CONST, {.i64=NOISE_MODE}, 0, 0, A, "mode" },
{ NULL }
};
AVFILTER_DEFINE_CLASS(anlms);
static int query_formats(AVFilterContext *ctx)
{
AVFilterFormats *formats;
AVFilterChannelLayouts *layouts;
static const enum AVSampleFormat sample_fmts[] = {
AV_SAMPLE_FMT_FLTP,
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 float fir_sample(AudioNLMSContext *s, float sample, float *delay,
float *coeffs, float *tmp, int *offset)
{
const int order = s->order;
float output;
delay[*offset] = sample;
memcpy(tmp, coeffs + order - *offset, order * sizeof(float));
output = s->fdsp->scalarproduct_float(delay, tmp, s->kernel_size);
if (--(*offset) < 0)
*offset = order - 1;
return output;
}
static float process_sample(AudioNLMSContext *s, float input, float desired,
float *delay, float *coeffs, float *tmp, int *offsetp)
{
const int order = s->order;
const float leakage = s->leakage;
const float mu = s->mu;
const float a = 1.f - leakage * mu;
float sum, output, e, norm, b;
int offset = *offsetp;
delay[offset + order] = input;
output = fir_sample(s, input, delay, coeffs, tmp, offsetp);
e = desired - output;
sum = s->fdsp->scalarproduct_float(delay, delay, s->kernel_size);
norm = s->eps + sum;
b = mu * e / norm;
memcpy(tmp, delay + offset, order * sizeof(float));
s->fdsp->vector_fmul_scalar(coeffs, coeffs, a, s->kernel_size);
s->fdsp->vector_fmac_scalar(coeffs, tmp, b, s->kernel_size);
memcpy(coeffs + order, coeffs, order * sizeof(float));
switch (s->output_mode) {
case IN_MODE: output = input; break;
case DESIRED_MODE: output = desired; break;
case OUT_MODE: /*output = output;*/ break;
case NOISE_MODE: output = desired - output; break;
}
return output;
}
static int process_channels(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
{
AudioNLMSContext *s = ctx->priv;
AVFrame *out = arg;
const int start = (out->channels * jobnr) / nb_jobs;
const int end = (out->channels * (jobnr+1)) / nb_jobs;
for (int c = start; c < end; c++) {
const float *input = (const float *)s->frame[0]->extended_data[c];
const float *desired = (const float *)s->frame[1]->extended_data[c];
float *delay = (float *)s->delay->extended_data[c];
float *coeffs = (float *)s->coeffs->extended_data[c];
float *tmp = (float *)s->tmp->extended_data[c];
int *offset = (int *)s->offset->extended_data[c];
float *output = (float *)out->extended_data[c];
for (int n = 0; n < out->nb_samples; n++)
output[n] = process_sample(s, input[n], desired[n], delay, coeffs, tmp, offset);
}
return 0;
}
static int activate(AVFilterContext *ctx)
{
AudioNLMSContext *s = ctx->priv;
int i, ret, status;
int nb_samples;
int64_t pts;
FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);
nb_samples = FFMIN(ff_inlink_queued_samples(ctx->inputs[0]),
ff_inlink_queued_samples(ctx->inputs[1]));
for (i = 0; i < ctx->nb_inputs && nb_samples > 0; i++) {
if (s->frame[i])
continue;
if (ff_inlink_check_available_samples(ctx->inputs[i], nb_samples) > 0) {
ret = ff_inlink_consume_samples(ctx->inputs[i], nb_samples, nb_samples, &s->frame[i]);
if (ret < 0)
return ret;
}
}
if (s->frame[0] && s->frame[1]) {
AVFrame *out;
out = ff_get_audio_buffer(ctx->outputs[0], s->frame[0]->nb_samples);
if (!out) {
av_frame_free(&s->frame[0]);
av_frame_free(&s->frame[1]);
return AVERROR(ENOMEM);
}
ctx->internal->execute(ctx, process_channels, out, NULL, FFMIN(ctx->outputs[0]->channels,
ff_filter_get_nb_threads(ctx)));
out->pts = s->frame[0]->pts;
av_frame_free(&s->frame[0]);
av_frame_free(&s->frame[1]);
ret = ff_filter_frame(ctx->outputs[0], out);
if (ret < 0)
return ret;
}
if (!nb_samples) {
for (i = 0; i < 2; i++) {
if (ff_inlink_acknowledge_status(ctx->inputs[i], &status, &pts)) {
ff_outlink_set_status(ctx->outputs[0], status, pts);
return 0;
}
}
}
if (ff_outlink_frame_wanted(ctx->outputs[0])) {
for (i = 0; i < 2; i++) {
if (ff_inlink_queued_samples(ctx->inputs[i]) > 0)
continue;
ff_inlink_request_frame(ctx->inputs[i]);
return 0;
}
}
return 0;
}
static int config_output(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
AudioNLMSContext *s = ctx->priv;
s->kernel_size = FFALIGN(s->order, 16);
if (!s->offset)
s->offset = ff_get_audio_buffer(outlink, 1);
if (!s->delay)
s->delay = ff_get_audio_buffer(outlink, 2 * s->kernel_size);
if (!s->coeffs)
s->coeffs = ff_get_audio_buffer(outlink, 2 * s->kernel_size);
if (!s->tmp)
s->tmp = ff_get_audio_buffer(outlink, s->kernel_size);
if (!s->delay || !s->coeffs || !s->offset || !s->tmp)
return AVERROR(ENOMEM);
return 0;
}
static av_cold int init(AVFilterContext *ctx)
{
AudioNLMSContext *s = ctx->priv;
s->fdsp = avpriv_float_dsp_alloc(0);
if (!s->fdsp)
return AVERROR(ENOMEM);
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
AudioNLMSContext *s = ctx->priv;
av_freep(&s->fdsp);
av_frame_free(&s->delay);
av_frame_free(&s->coeffs);
av_frame_free(&s->offset);
av_frame_free(&s->tmp);
}
static const AVFilterPad inputs[] = {
{
.name = "input",
.type = AVMEDIA_TYPE_AUDIO,
},
{
.name = "desired",
.type = AVMEDIA_TYPE_AUDIO,
},
{ NULL }
};
static const AVFilterPad outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_output,
},
{ NULL }
};
AVFilter ff_af_anlms = {
.name = "anlms",
.description = NULL_IF_CONFIG_SMALL("Apply Normalized Least-Mean-Squares algorithm to first audio stream."),
.priv_size = sizeof(AudioNLMSContext),
.priv_class = &anlms_class,
.init = init,
.uninit = uninit,
.activate = activate,
.query_formats = query_formats,
.inputs = inputs,
.outputs = outputs,
.flags = AVFILTER_FLAG_SLICE_THREADS,
};

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@ -56,6 +56,7 @@ extern AVFilter ff_af_amix;
extern AVFilter ff_af_amultiply;
extern AVFilter ff_af_anequalizer;
extern AVFilter ff_af_anlmdn;
extern AVFilter ff_af_anlms;
extern AVFilter ff_af_anull;
extern AVFilter ff_af_apad;
extern AVFilter ff_af_aperms;

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@ -30,7 +30,7 @@
#include "libavutil/version.h"
#define LIBAVFILTER_VERSION_MAJOR 7
#define LIBAVFILTER_VERSION_MINOR 61
#define LIBAVFILTER_VERSION_MINOR 62
#define LIBAVFILTER_VERSION_MICRO 100