aphaser filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Changelog

@@ -15,6 +15,7 @@ version <next>:
 - new ffmpeg options -filter_script and -filter_complex_script, which allow a
   filtergraph description to be read from a file
 - OpenCL support
+- audio phaser filter
 
 
 version 1.2:

doc/filters.texi

@@ -6266,6 +6266,43 @@ following one, the permission might not be received as expected in that
 following filter. Inserting a @ref{format} or @ref{aformat} filter before the
 perms/aperms filter can avoid this problem.
 
+@section aphaser
+Add a phasing effect to the input audio.
+
+A phaser filter creates series of peaks and troughs in the frequency spectrum.
+The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
+
+The filter accepts parameters as a list of @var{key}=@var{value}
+pairs, separated by ":".
+
+A description of the accepted parameters follows.
+
+@table @option
+@item in_gain
+Set input gain. Default is 0.4.
+
+@item out_gain
+Set output gain. Default is 0.74
+
+@item delay
+Set delay in milliseconds. Default is 3.0.
+
+@item decay
+Set decay. Default is 0.4.
+
+@item speed
+Set modulation speed in Hz. Default is 0.5.
+
+@item type
+Set modulation type. Default is triangular.
+
+It accepts the following values:
+@table @samp
+@item triangular, t
+@item sinusoidal, s
+@end table
+@end table
+
 @section aselect, select
 Select frames to pass in output.
 

libavfilter/Makefile

@@ -58,6 +58,7 @@ OBJS-$(CONFIG_AMIX_FILTER)                   += af_amix.o
 OBJS-$(CONFIG_ANULL_FILTER)                  += af_anull.o
 OBJS-$(CONFIG_APAD_FILTER)                   += af_apad.o
 OBJS-$(CONFIG_APERMS_FILTER)                 += f_perms.o
+OBJS-$(CONFIG_APHASER_FILTER)                += af_aphaser.o
 OBJS-$(CONFIG_ARESAMPLE_FILTER)              += af_aresample.o
 OBJS-$(CONFIG_ASELECT_FILTER)                += f_select.o
 OBJS-$(CONFIG_ASENDCMD_FILTER)               += f_sendcmd.o

libavfilter/allfilters.c

@@ -54,6 +54,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(ANULL,          anull,          af);
     REGISTER_FILTER(APAD,           apad,           af);
     REGISTER_FILTER(APERMS,         aperms,         af);
+    REGISTER_FILTER(APHASER,        aphaser,        af);
     REGISTER_FILTER(ARESAMPLE,      aresample,      af);
     REGISTER_FILTER(ASELECT,        aselect,        af);
     REGISTER_FILTER(ASENDCMD,       asendcmd,       af);

libavfilter/version.h

@@ -29,8 +29,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  48
-#define LIBAVFILTER_VERSION_MICRO 105
+#define LIBAVFILTER_VERSION_MINOR  49
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \