avfilter: add audio denoising (afftdn) filter

Changelog

@@ -31,6 +31,7 @@ version <next>:
 - Block-Matching 3d (bm3d) denoising filter
 - acrossover filter
 - ilbc decoder
+- audio denoiser as afftdn filter
 
 
 version 4.0:

configure

@@ -3339,6 +3339,8 @@ libssh_protocol_deps="libssh"
 libtls_conflict="openssl gnutls mbedtls"
 
 # filters
+afftdn_filter_deps="avcodec"
+afftdn_filter_select="fft"
 afftfilt_filter_deps="avcodec"
 afftfilt_filter_select="fft"
 afir_filter_deps="avcodec"
@@ -6857,6 +6859,7 @@ done
 enabled zlib && add_cppflags -DZLIB_CONST
 
 # conditional library dependencies, in any order
+enabled afftdn_filter       && prepend avfilter_deps "avcodec"
 enabled afftfilt_filter     && prepend avfilter_deps "avcodec"
 enabled afir_filter         && prepend avfilter_deps "avcodec"
 enabled amovie_filter       && prepend avfilter_deps "avformat avcodec"

doc/filters.texi

@@ -974,6 +974,96 @@ afade=t=out:st=875:d=25
 @end example
 @end itemize
 
+@section afftdn
+Denoise audio samples with FFT.
+
+A description of the accepted parameters follows.
+
+@table @option
+@item nr
+Set the noise reduction in dB, allowed range is 0.01 to 97.
+Default value is 12 dB.
+
+@item nf
+Set the noise floor in dB, allowed range is -80 to -20.
+Default value is -50 dB.
+
+@item nt
+Set the noise type.
+
+It accepts the following values:
+@table @option
+@item w
+Select white noise.
+
+@item v
+Select vinyl noise.
+
+@item s
+Select shellac noise.
+
+@item c
+Select custom noise, defined in @code{bn} option.
+
+Default value is white noise.
+@end table
+
+@item bn
+Set custom band noise for every one of 15 bands.
+Bands are separated by ' ' or '|'.
+
+@item rf
+Set the residual floor in dB, allowed range is -80 to -20.
+Default value is -38 dB.
+
+@item tn
+Enable noise tracking. By default is disabled.
+With this enabled, noise floor is automatically adjusted.
+
+@item tr
+Enable residual tracking. By default is disabled.
+
+@item om
+Set the output mode.
+
+It accepts the following values:
+@table @option
+@item i
+Pass input unchanged.
+
+@item o
+Pass noise filtered out.
+
+@item n
+Pass only noise.
+
+Default value is @var{o}.
+@end table
+@end table
+
+@subsection Commands
+
+This filter supports the following commands:
+@table @option
+@item sample_noise, sn
+Start or stop measuring noise profile.
+Syntax for the command is : "start" or "stop" string.
+After measuring noise profile is stopped it will be
+automatically applied in filtering.
+
+@item noise_reduction, nr
+Change noise reduction. Argument is single float number.
+Syntax for the command is : "@var{noise_reduction}"
+
+@item noise_floor, nf
+Change noise floor. Argument is single float number.
+Syntax for the command is : "@var{noise_floor}"
+
+@item output_mode, om
+Change output mode operation.
+Syntax for the command is : "i", "o" or "n" string.
+@end table
+
 @section afftfilt
 Apply arbitrary expressions to samples in frequency domain.
 

libavfilter/Makefile

@@ -46,6 +46,7 @@ OBJS-$(CONFIG_AECHO_FILTER)                  += af_aecho.o
 OBJS-$(CONFIG_AEMPHASIS_FILTER)              += af_aemphasis.o
 OBJS-$(CONFIG_AEVAL_FILTER)                  += aeval.o
 OBJS-$(CONFIG_AFADE_FILTER)                  += af_afade.o
+OBJS-$(CONFIG_AFFTDN_FILTER)                 += af_afftdn.o
 OBJS-$(CONFIG_AFFTFILT_FILTER)               += af_afftfilt.o
 OBJS-$(CONFIG_AFIR_FILTER)                   += af_afir.o
 OBJS-$(CONFIG_AFORMAT_FILTER)                += af_aformat.o

libavfilter/allfilters.c

@@ -39,6 +39,7 @@ extern AVFilter ff_af_aecho;
 extern AVFilter ff_af_aemphasis;
 extern AVFilter ff_af_aeval;
 extern AVFilter ff_af_afade;
+extern AVFilter ff_af_afftdn;
 extern AVFilter ff_af_afftfilt;
 extern AVFilter ff_af_afir;
 extern AVFilter ff_af_aformat;

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   7
-#define LIBAVFILTER_VERSION_MINOR  32
+#define LIBAVFILTER_VERSION_MINOR  33
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \