avfilter: add lv2 wrapper filter

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

Changelog

@@ -20,6 +20,7 @@ version <next>:
 - OpenCL overlay filter
 - video mix filter
 - video normalize filter
+- audio lv2 wrapper filter
 
 
 version 3.4:

configure

@@ -283,6 +283,7 @@ External library support:
   --enable-libzimg         enable z.lib, needed for zscale filter [no]
   --enable-libzmq          enable message passing via libzmq [no]
   --enable-libzvbi         enable teletext support via libzvbi [no]
+  --enable-lv2             enable LV2 audio filtering [no]
   --disable-lzma           disable lzma [autodetect]
   --enable-decklink        enable Blackmagic DeckLink I/O support [no]
   --enable-libndi_newtek   enable Newteck NDI I/O support [no]
@@ -1631,6 +1632,7 @@ EXTERNAL_LIBRARY_LIST="
     libzimg
     libzmq
     libzvbi
+    lv2
     mediacodec
     openal
     opengl
@@ -3229,6 +3231,7 @@ hqdn3d_filter_deps="gpl"
 interlace_filter_deps="gpl"
 kerndeint_filter_deps="gpl"
 ladspa_filter_deps="ladspa libdl"
+lv2_filter_deps="lv2"
 mcdeint_filter_deps="avcodec gpl"
 movie_filter_deps="avcodec avformat"
 mpdecimate_filter_deps="gpl"
@@ -5825,6 +5828,7 @@ enabled gmp               && require gmp gmp.h mpz_export -lgmp
 enabled gnutls            && require_pkg_config gnutls gnutls gnutls/gnutls.h gnutls_global_init
 enabled jni               && { [ $target_os = "android" ] && check_header jni.h && enabled pthreads || die "ERROR: jni not found"; }
 enabled ladspa            && require_header ladspa.h
+enabled lv2               && require_pkg_config lv2 lilv-0 "lilv-0/lilv/lilv.h" lilv_world_new
 enabled libiec61883       && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
 enabled libass            && require_pkg_config libass libass ass/ass.h ass_library_init
 enabled libbluray         && require_pkg_config libbluray libbluray libbluray/bluray.h bd_open

doc/filters.texi

@@ -3281,6 +3281,65 @@ lowpass=c=LFE
 @end example
 @end itemize
 
+@section lv2
+
+Load a LV2 (LADSPA Version 2) plugin.
+
+To enable compilation of this filter you need to configure FFmpeg with
+@code{--enable-lv2}.
+
+@table @option
+@item plugin, p
+Specifies the plugin URI. You may need to escape ':'.
+
+@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).
+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
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+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
+Apply bass enhancer plugin from Calf:
+@example
+lv2=p=http\\\\://calf.sourceforge.net/plugins/BassEnhancer:c=amount=2
+@end example
+
+@item
+Apply bass vinyl plugin from Calf:
+@example
+lv2=p=http\\\\://calf.sourceforge.net/plugins/Vinyl:c=drone=0.2|aging=0.5
+@end example
+
+@item
+Apply bit crusher plugin from ArtyFX:
+@example
+lv2=p=http\\\\://www.openavproductions.com/artyfx#bitta:c=crush=0.3
+@end example
+@end itemize
+
 @section mcompand
 Multiband Compress or expand the audio's dynamic range.
 

libavfilter/Makefile

@@ -101,6 +101,7 @@ OBJS-$(CONFIG_JOIN_FILTER)                   += af_join.o
 OBJS-$(CONFIG_LADSPA_FILTER)                 += af_ladspa.o
 OBJS-$(CONFIG_LOUDNORM_FILTER)               += af_loudnorm.o ebur128.o
 OBJS-$(CONFIG_LOWPASS_FILTER)                += af_biquads.o
+OBJS-$(CONFIG_LV2_FILTER)                    += af_lv2.o
 OBJS-$(CONFIG_MCOMPAND_FILTER)               += af_mcompand.o
 OBJS-$(CONFIG_PAN_FILTER)                    += af_pan.o
 OBJS-$(CONFIG_REPLAYGAIN_FILTER)             += af_replaygain.o

libavfilter/allfilters.c

@@ -112,6 +112,7 @@ static void register_all(void)
     REGISTER_FILTER(LADSPA,         ladspa,         af);
     REGISTER_FILTER(LOUDNORM,       loudnorm,       af);
     REGISTER_FILTER(LOWPASS,        lowpass,        af);
+    REGISTER_FILTER(LV2,            lv2,            af);
     REGISTER_FILTER(MCOMPAND,       mcompand,       af);
     REGISTER_FILTER(PAN,            pan,            af);
     REGISTER_FILTER(REPLAYGAIN,     replaygain,     af);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   7
-#define LIBAVFILTER_VERSION_MINOR   4
+#define LIBAVFILTER_VERSION_MINOR   5
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \