avfilter: add ladspa wrapper filter

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

Changelog

@@ -35,6 +35,7 @@ version <next>
 - Fraps: use BT.709 colorspace by default for yuv, as reference fraps decoder does
 - make decoding alpha optional for prores, ffv1 and vp6 by setting
   the skip_alpha flag.
+- ladspa wrapper filter
 
 
 version 2.0:

configure

@@ -193,6 +193,7 @@ External library support:
   --enable-frei0r          enable frei0r video filtering
   --enable-gnutls          enable gnutls [no]
   --disable-iconv          disable iconv [autodetect]
+  --enable-ladspa          enable LADSPA audio filtering
   --enable-libaacplus      enable AAC+ encoding via libaacplus [no]
   --enable-libass          enable libass subtitles rendering [no]
   --enable-libbluray       enable BluRay reading using libbluray [no]
@@ -1162,6 +1163,7 @@ EXTERNAL_LIBRARY_LIST="
     frei0r
     gnutls
     iconv
+    ladspa
     libaacplus
     libass
     libbluray
@@ -2210,6 +2212,7 @@ histeq_filter_deps="gpl"
 hqdn3d_filter_deps="gpl"
 interlace_filter_deps="gpl"
 kerndeint_filter_deps="gpl"
+ladspa_filter_deps="ladspa dlopen"
 mcdeint_filter_deps="avcodec gpl"
 movie_filter_deps="avcodec avformat"
 mp_filter_deps="gpl avcodec swscale inline_asm"
@@ -4210,6 +4213,7 @@ enabled avisynth          && { { check_lib2 "windows.h" LoadLibrary; } ||
 enabled fontconfig        && require_pkg_config fontconfig "fontconfig/fontconfig.h" FcInit
 enabled frei0r            && { check_header frei0r.h || die "ERROR: frei0r.h header not found"; }
 enabled gnutls            && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
+enabled ladspa            && { check_header ladspa.h || die "ERROR: ladspa.h header not found"; }
 enabled libiec61883       && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
 enabled libaacplus        && require "libaacplus >= 2.0.0" aacplus.h aacplusEncOpen -laacplus
 enabled libass            && require_pkg_config libass ass/ass.h ass_library_init

doc/filters.texi

@@ -1400,6 +1400,104 @@ ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
 out
 @end example
 
+@section ladspa
+
+Load a LADSPA (Linux Audio Developer's Simple Plugin API) plugin.
+
+@table @option
+@item file, f
+Specifies the name of LADSPA plugin library to load. If the environment
+variable @env{LADSPA_PATH} is defined, the LADSPA plugin is searched in
+each one of the directories specified by the colon separated list in
+@env{LADSPA_PATH}, otherwise in the standard LADSPA paths, which are in
+this order: @file{HOME/.ladspa/lib/}, @file{/usr/local/lib/ladspa/},
+@file{/usr/lib/ladspa/}.
+
+@item plugin, p
+Specifies the plugin within the library. Some libraries contain only
+one plugin, but others contain many of them. If this is not set filter
+will list all available plugins within the specified library.
+
+@item controls, c
+Set the '|' separated list of controls which are zero or more floating point
+values that determine the behavior of the loaded plugin (for example delay,
+threshold or gain).
+Controls need to be defined using the following syntax:
+c0=@var{value0}|c1=@var{value1}|c2=@var{value2}|..., where
+@var{valuei} is the value set on the @var{i}-th control.
+If @option{controls} is set to @code{help}, all available controls and
+their valid ranges are printed.
+
+@item sample_rate, s
+Specify the sample rate, default to 44100. Only used if plugin have
+zero inputs.
+
+@item nb_samples, n
+Set the number of samples per channel per each output frame, default
+is 1024. Only used if plugin have zero inputs.
+
+@item duration, d
+Set the minimum duration of the sourced audio. See the function
+@code{av_parse_time()} for the accepted format, also check the "Time duration"
+section in the ffmpeg-utils manual.
+Note that the resulting duration may be greater than the specified duration,
+as the generated audio is always cut at the end of a complete frame.
+If not specified, or the expressed duration is negative, the audio is
+supposed to be generated forever.
+Only used if plugin have zero inputs.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+List all available plugins within amp (LADSPA example plugin) library:
+@example
+ladspa=file=amp
+@end example
+
+@item
+List all available controls and their valid ranges for @code{vcf_notch}
+plugin from @code{VCF} library:
+@example
+ladspa=f=vcf:p=vcf_notch:c=help
+@end example
+
+@item
+Simulate low quality audio equipment using @code{Computer Music Toolkit} (CMT)
+plugin library:
+@example
+ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
+@end example
+
+@item
+Add reverberation to the audio using TAP-plugins
+(Tom's Audio Processing plugins):
+@example
+ladspa=file=tap_reverb:tap_reverb
+@end example
+
+@item
+Generate white noise, with 0.2 amplitude:
+@example
+ladspa=file=cmt:noise_source_white:c=c0=.2
+@end example
+
+@item
+Generate 20 bpm clicks using plugin @code{C* Click - Metronome} from the
+@code{C* Audio Plugin Suite} (CAPS) library:
+@example
+ladspa=file=caps:Click:c=c1=20'
+@end example
+
+@item
+Apply @code{C* Eq10X2 - Stereo 10-band equaliser} effect:
+@example
+ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
+@end example
+@end itemize
+
 @section lowpass
 
 Apply a low-pass filter with 3dB point frequency.

libavfilter/Makefile

@@ -91,6 +91,7 @@ OBJS-$(CONFIG_EBUR128_FILTER)                += f_ebur128.o
 OBJS-$(CONFIG_EQUALIZER_FILTER)              += af_biquads.o
 OBJS-$(CONFIG_HIGHPASS_FILTER)               += af_biquads.o
 OBJS-$(CONFIG_JOIN_FILTER)                   += af_join.o
+OBJS-$(CONFIG_LADSPA_FILTER)                 += af_ladspa.o
 OBJS-$(CONFIG_LOWPASS_FILTER)                += af_biquads.o
 OBJS-$(CONFIG_PAN_FILTER)                    += af_pan.o
 OBJS-$(CONFIG_RESAMPLE_FILTER)               += af_resample.o

libavfilter/allfilters.c

@@ -87,6 +87,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(EQUALIZER,      equalizer,      af);
     REGISTER_FILTER(HIGHPASS,       highpass,       af);
     REGISTER_FILTER(JOIN,           join,           af);
+    REGISTER_FILTER(LADSPA,         ladspa,         af);
     REGISTER_FILTER(LOWPASS,        lowpass,        af);
     REGISTER_FILTER(PAN,            pan,            af);
     REGISTER_FILTER(RESAMPLE,       resample,       af);

libavfilter/version.h

@@ -30,8 +30,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  86
-#define LIBAVFILTER_VERSION_MICRO 102
+#define LIBAVFILTER_VERSION_MINOR  87
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \