avfilter: add lv2 wrapper filter

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

7 files changed, 669 insertions, 1 deletions

diff --git a/Changelog b/Changelog
index 0b7e02392d..e3092e211f 100644
--- a/Changelog
+++ b/Changelog
@@ -20,6 +20,7 @@ version <next>:
 - OpenCL overlay filter
 - video mix filter
 - video normalize filter
+- audio lv2 wrapper filter
 
 
 version 3.4:
diff --git a/configure b/configure
index 7769427ffb..0cc97ebbbb 100755
--- a/configure
+++ b/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
diff --git a/doc/filters.texi b/doc/filters.texi
index fda789630b..476f014ac8 100644
--- a/doc/filters.texi
+++ b/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.
 
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index dd195d2538..0b77d7a01f 100644
--- a/libavfilter/Makefile
+++ b/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
diff --git a/libavfilter/af_lv2.c b/libavfilter/af_lv2.c
new file mode 100644
index 0000000000..8a0a6fd888
--- /dev/null
+++ b/libavfilter/af_lv2.c
@@ -0,0 +1,602 @@
+/*
+ * Copyright (c) 2017 Paul B Mahol
+ * Copyright (c) 2007-2016 David Robillard <http://drobilla.net>
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * LV2 wrapper
+ */
+
+#include <lilv/lilv.h>
+#include <lv2/lv2plug.in/ns/ext/atom/atom.h>
+#include <lv2/lv2plug.in/ns/ext/buf-size/buf-size.h>
+
+#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
+#include "libavutil/channel_layout.h"
+#include "libavutil/opt.h"
+#include "audio.h"
+#include "avfilter.h"
+#include "internal.h"
+
+typedef struct URITable {
+    char    **uris;
+    size_t    n_uris;
+} URITable;
+
+typedef struct LV2Context {
+    const AVClass *class;
+    char *plugin_uri;
+    char *options;
+
+    unsigned nb_inputs;
+    unsigned nb_inputcontrols;
+    unsigned nb_outputs;
+
+    int sample_rate;
+    int nb_samples;
+    int64_t pts;
+    int64_t duration;
+
+    LilvWorld         *world;
+    const LilvPlugin  *plugin;
+    uint32_t           nb_ports;
+    float             *values;
+    URITable           uri_table;
+    LV2_URID_Map       map;
+    LV2_Feature        map_feature;
+    LV2_URID_Unmap     unmap;
+    LV2_Feature        unmap_feature;
+    LV2_Atom_Sequence  seq_in[2];
+    LV2_Atom_Sequence *seq_out;
+    const LV2_Feature *features[5];
+
+    float *mins;
+    float *maxes;
+    float *controls;
+
+    LilvInstance *instance;
+
+    LilvNode  *atom_AtomPort;
+    LilvNode  *atom_Sequence;
+    LilvNode  *lv2_AudioPort;
+    LilvNode  *lv2_CVPort;
+    LilvNode  *lv2_ControlPort;
+    LilvNode  *lv2_Optional;
+    LilvNode  *lv2_InputPort;
+    LilvNode  *lv2_OutputPort;
+    LilvNode  *urid_map;
+    LilvNode  *powerOf2BlockLength;
+    LilvNode  *fixedBlockLength;
+    LilvNode  *boundedBlockLength;
+} LV2Context;
+
+#define OFFSET(x) offsetof(LV2Context, x)
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption lv2_options[] = {
+    { "plugin", "set plugin uri", OFFSET(plugin_uri), AV_OPT_TYPE_STRING, .flags = FLAGS },
+    { "p",      "set plugin uri", OFFSET(plugin_uri), AV_OPT_TYPE_STRING, .flags = FLAGS },
+    { "controls", "set plugin options", OFFSET(options), AV_OPT_TYPE_STRING, .flags = FLAGS },
+    { "c",        "set plugin options", OFFSET(options), AV_OPT_TYPE_STRING, .flags = FLAGS },
+    { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT32_MAX, FLAGS },
+    { "s",           "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT32_MAX, FLAGS },
+    { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
+    { "n",          "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
+    { "duration", "set audio duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64=-1}, -1, INT64_MAX, FLAGS },
+    { "d",        "set audio duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64=-1}, -1, INT64_MAX, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(lv2);
+
+static void uri_table_init(URITable *table)
+{
+    table->uris   = NULL;
+    table->n_uris = 0;
+}
+
+static void uri_table_destroy(URITable *table)
+{
+    int i;
+
+    for (i = 0; i < table->n_uris; i++) {
+        av_freep(&table->uris[i]);
+    }
+
+    av_freep(&table->uris);
+}
+
+static LV2_URID uri_table_map(LV2_URID_Map_Handle handle, const char *uri)
+{
+    URITable *table = (URITable*)handle;
+    const size_t len = strlen(uri);
+    size_t i;
+    char **tmp;
+
+    for (i = 0; i < table->n_uris; i++) {
+        if (!strcmp(table->uris[i], uri)) {
+            return i + 1;
+        }
+    }
+
+    tmp = av_calloc(table->n_uris + 1, sizeof(char*));
+    if (!tmp)
+        return table->n_uris;
+    memcpy(tmp, table->uris, table->n_uris * sizeof(char**));
+
+    av_free(table->uris);
+    table->uris = tmp;
+    table->uris[table->n_uris] = av_malloc(len + 1);
+    if (!table->uris[table->n_uris])
+        return table->n_uris;
+
+    memcpy(table->uris[table->n_uris], uri, len + 1);
+    table->n_uris++;
+
+    return table->n_uris;
+}
+
+static const char *uri_table_unmap(LV2_URID_Map_Handle handle, LV2_URID urid)
+{
+    URITable *table = (URITable*)handle;
+
+    if (urid > 0 && urid <= table->n_uris) {
+        return table->uris[urid - 1];
+    }
+
+    return NULL;
+}
+
+static void connect_ports(LV2Context *s, AVFrame *in, AVFrame *out)
+{
+    int ich = 0, och = 0, i;
+
+    for (i = 0; i < s->nb_ports; i++) {
+        const LilvPort *port = lilv_plugin_get_port_by_index(s->plugin, i);
+
+        if (lilv_port_is_a(s->plugin, port, s->lv2_AudioPort) ||
+            lilv_port_is_a(s->plugin, port, s->lv2_CVPort)) {
+            if (lilv_port_is_a(s->plugin, port, s->lv2_InputPort)) {
+                lilv_instance_connect_port(s->instance, i, in->extended_data[ich++]);
+            } else if (lilv_port_is_a(s->plugin, port, s->lv2_OutputPort)) {
+                lilv_instance_connect_port(s->instance, i, out->extended_data[och++]);
+            } else {
+                av_log(s, AV_LOG_WARNING, "port %d neither input nor output, skipping\n", i);
+            }
+        } else if (lilv_port_is_a(s->plugin, port, s->atom_AtomPort)) {
+            if (lilv_port_is_a(s->plugin, port, s->lv2_InputPort)) {
+                lilv_instance_connect_port(s->instance, i, &s->seq_in);
+            } else {
+                lilv_instance_connect_port(s->instance, i, s->seq_out);
+            }
+        } else if (lilv_port_is_a(s->plugin, port, s->lv2_ControlPort)) {
+            lilv_instance_connect_port(s->instance, i, &s->controls[i]);
+        }
+    }
+
+    s->seq_in[0].atom.size = sizeof(LV2_Atom_Sequence_Body);
+    s->seq_in[0].atom.type = uri_table_map(&s->uri_table, LV2_ATOM__Sequence);
+    s->seq_out->atom.size  = 9624;
+    s->seq_out->atom.type  = uri_table_map(&s->uri_table, LV2_ATOM__Chunk);
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    LV2Context *s = ctx->priv;
+    AVFrame *out;
+
+    if (!s->nb_outputs ||
+        (av_frame_is_writable(in) && s->nb_inputs == s->nb_outputs)) {
+        out = in;
+    } else {
+        out = ff_get_audio_buffer(ctx->outputs[0], in->nb_samples);
+        if (!out) {
+            av_frame_free(&in);
+            return AVERROR(ENOMEM);
+        }
+        av_frame_copy_props(out, in);
+    }
+
+    connect_ports(s, in, out);
+
+    lilv_instance_run(s->instance, in->nb_samples);
+
+    if (out != in)
+        av_frame_free(&in);
+
+    return ff_filter_frame(ctx->outputs[0], out);
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    LV2Context *s = ctx->priv;
+    AVFrame *out;
+    int64_t t;
+
+    if (ctx->nb_inputs)
+        return ff_request_frame(ctx->inputs[0]);
+
+    t = av_rescale(s->pts, AV_TIME_BASE, s->sample_rate);
+    if (s->duration >= 0 && t >= s->duration)
+        return AVERROR_EOF;
+
+    out = ff_get_audio_buffer(outlink, s->nb_samples);
+    if (!out)
+        return AVERROR(ENOMEM);
+
+    connect_ports(s, out, out);
+
+    lilv_instance_run(s->instance, out->nb_samples);
+
+    out->sample_rate = s->sample_rate;
+    out->pts         = s->pts;
+    s->pts          += s->nb_samples;
+
+    return ff_filter_frame(outlink, out);
+}
+
+static const LV2_Feature buf_size_features[3] = {
+    { LV2_BUF_SIZE__powerOf2BlockLength, NULL },
+    { LV2_BUF_SIZE__fixedBlockLength,    NULL },
+    { LV2_BUF_SIZE__boundedBlockLength,  NULL },
+};
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    LV2Context *s = ctx->priv;
+    char *p, *arg, *saveptr = NULL;
+    int i, sample_rate;
+
+    uri_table_init(&s->uri_table);
+    s->map.handle = &s->uri_table;
+    s->map.map = uri_table_map;
+    s->map_feature.URI = LV2_URID_MAP_URI;
+    s->map_feature.data = &s->map;
+    s->unmap.handle = &s->uri_table;
+    s->unmap.unmap  = uri_table_unmap;
+    s->unmap_feature.URI = LV2_URID_UNMAP_URI;
+    s->unmap_feature.data = &s->unmap;
+    s->features[0] = &s->map_feature;
+    s->features[1] = &s->unmap_feature;
+    s->features[2] = &buf_size_features[0];
+    s->features[3] = &buf_size_features[1];
+    s->features[4] = &buf_size_features[2];
+
+    if (ctx->nb_inputs) {
+        AVFilterLink *inlink = ctx->inputs[0];
+
+        outlink->format      = inlink->format;
+        outlink->sample_rate = sample_rate = inlink->sample_rate;
+        if (s->nb_inputs == s->nb_outputs) {
+            outlink->channel_layout = inlink->channel_layout;
+            outlink->channels = inlink->channels;
+        }
+
+    } else {
+        outlink->sample_rate = sample_rate = s->sample_rate;
+        outlink->time_base   = (AVRational){1, s->sample_rate};
+    }
+
+    s->instance = lilv_plugin_instantiate(s->plugin, sample_rate, s->features);
+    if (!s->instance) {
+        av_log(s, AV_LOG_ERROR, "Failed to instantiate <%s>\n", lilv_node_as_uri(lilv_plugin_get_uri(s->plugin)));
+        return AVERROR(EINVAL);
+    }
+
+    s->mins     = av_calloc(s->nb_ports, sizeof(float));
+    s->maxes    = av_calloc(s->nb_ports, sizeof(float));
+    s->controls = av_calloc(s->nb_ports, sizeof(float));
+
+    if (!s->mins || !s->maxes || !s->controls)
+        return AVERROR(ENOMEM);
+
+    lilv_plugin_get_port_ranges_float(s->plugin, s->mins, s->maxes, s->controls);
+    s->seq_out = av_malloc(sizeof(LV2_Atom_Sequence) + 9624);
+    if (!s->seq_out)
+        return AVERROR(ENOMEM);
+
+    if (s->options && !strcmp(s->options, "help")) {
+        if (!s->nb_inputcontrols) {
+            av_log(ctx, AV_LOG_INFO,
+                   "The '%s' plugin does not have any input controls.\n",
+                   s->plugin_uri);
+        } else {
+            av_log(ctx, AV_LOG_INFO,
+                   "The '%s' plugin has the following input controls:\n",
+                   s->plugin_uri);
+            for (i = 0; i < s->nb_ports; i++) {
+                const LilvPort *port = lilv_plugin_get_port_by_index(s->plugin, i);
+                const LilvNode *symbol = lilv_port_get_symbol(s->plugin, port);
+                LilvNode *name = lilv_port_get_name(s->plugin, port);
+
+                if (lilv_port_is_a(s->plugin, port, s->lv2_InputPort) &&
+                    lilv_port_is_a(s->plugin, port, s->lv2_ControlPort)) {
+                    av_log(ctx, AV_LOG_INFO, "%s\t\t<float> (from %f to %f) (default %f)\t\t%s\n",
+                           lilv_node_as_string(symbol), s->mins[i], s->maxes[i], s->controls[i],
+                           lilv_node_as_string(name));
+                }
+
+                lilv_node_free(name);
+            }
+        }
+        return AVERROR_EXIT;
+    }
+
+    p = s->options;
+    while (s->options) {
+        const LilvPort *port;
+        LilvNode *sym;
+        float val;
+        char *str, *vstr;
+        int index;
+
+        if (!(arg = av_strtok(p, " |", &saveptr)))
+            break;
+        p = NULL;
+
+        vstr = strstr(arg, "=");
+        if (vstr == NULL) {
+            av_log(ctx, AV_LOG_ERROR, "Invalid syntax.\n");
+            return AVERROR(EINVAL);
+        }
+
+        vstr[0] = 0;
+        str  = arg;
+        val  = atof(vstr+1);
+        sym  = lilv_new_string(s->world, str);
+        port = lilv_plugin_get_port_by_symbol(s->plugin, sym);
+        lilv_node_free(sym);
+        if (!port) {
+            av_log(s, AV_LOG_WARNING, "Unknown option: <%s>\n", str);
+        } else {
+            index = lilv_port_get_index(s->plugin, port);
+            s->controls[index] = val;
+        }
+    }
+
+    if (s->nb_inputs &&
+        (lilv_plugin_has_feature(s->plugin, s->powerOf2BlockLength) ||
+         lilv_plugin_has_feature(s->plugin, s->fixedBlockLength) ||
+         lilv_plugin_has_feature(s->plugin, s->boundedBlockLength))) {
+        AVFilterLink *inlink = ctx->inputs[0];
+
+        inlink->partial_buf_size = inlink->min_samples = inlink->max_samples = 4096;
+    }
+
+    return 0;
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    LV2Context *s = ctx->priv;
+    const LilvPlugins *plugins;
+    const LilvPlugin *plugin;
+    AVFilterPad pad = { NULL };
+    LilvNode *uri;
+    int i;
+
+    s->world = lilv_world_new();
+    if (!s->world)
+        return AVERROR(ENOMEM);
+
+    uri = lilv_new_uri(s->world, s->plugin_uri);
+    if (!uri) {
+        av_log(s, AV_LOG_ERROR, "Invalid plugin URI <%s>\n", s->plugin_uri);
+        return AVERROR(EINVAL);
+    }
+
+    lilv_world_load_all(s->world);
+    plugins = lilv_world_get_all_plugins(s->world);
+    plugin  = lilv_plugins_get_by_uri(plugins, uri);
+    lilv_node_free(uri);
+
+    if (!plugin) {
+        av_log(s, AV_LOG_ERROR, "Plugin <%s> not found\n", s->plugin_uri);
+        return AVERROR(EINVAL);
+    }
+
+    s->plugin = plugin;
+    s->nb_ports = lilv_plugin_get_num_ports(s->plugin);
+
+    s->lv2_InputPort       = lilv_new_uri(s->world, LV2_CORE__InputPort);
+    s->lv2_OutputPort      = lilv_new_uri(s->world, LV2_CORE__OutputPort);
+    s->lv2_AudioPort       = lilv_new_uri(s->world, LV2_CORE__AudioPort);
+    s->lv2_ControlPort     = lilv_new_uri(s->world, LV2_CORE__ControlPort);
+    s->lv2_Optional        = lilv_new_uri(s->world, LV2_CORE__connectionOptional);
+    s->atom_AtomPort       = lilv_new_uri(s->world, LV2_ATOM__AtomPort);
+    s->atom_Sequence       = lilv_new_uri(s->world, LV2_ATOM__Sequence);
+    s->urid_map            = lilv_new_uri(s->world, LV2_URID__map);
+    s->powerOf2BlockLength = lilv_new_uri(s->world, LV2_BUF_SIZE__powerOf2BlockLength);
+    s->fixedBlockLength    = lilv_new_uri(s->world, LV2_BUF_SIZE__fixedBlockLength);
+    s->boundedBlockLength  = lilv_new_uri(s->world, LV2_BUF_SIZE__boundedBlockLength);
+
+    for (i = 0; i < s->nb_ports; i++) {
+        const LilvPort *lport = lilv_plugin_get_port_by_index(s->plugin, i);
+        int is_input = 0;
+        int is_optional = 0;
+
+        is_optional = lilv_port_has_property(s->plugin, lport, s->lv2_Optional);
+
+        if (lilv_port_is_a(s->plugin, lport, s->lv2_InputPort)) {
+            is_input = 1;
+        } else if (!lilv_port_is_a(s->plugin, lport, s->lv2_OutputPort) && !is_optional) {
+            return AVERROR(EINVAL);
+        }
+
+        if (lilv_port_is_a(s->plugin, lport, s->lv2_ControlPort)) {
+            if (is_input) {
+                s->nb_inputcontrols++;
+            }
+        } else if (lilv_port_is_a(s->plugin, lport, s->lv2_AudioPort)) {
+            if (is_input) {
+                s->nb_inputs++;
+            } else {
+                s->nb_outputs++;
+            }
+        }
+    }
+
+    pad.type = AVMEDIA_TYPE_AUDIO;
+
+    if (s->nb_inputs) {
+        pad.name = av_asprintf("in0:%s:%u", s->plugin_uri, s->nb_inputs);
+        if (!pad.name)
+            return AVERROR(ENOMEM);
+
+        pad.filter_frame = filter_frame;
+        if (ff_insert_inpad(ctx, ctx->nb_inputs, &pad) < 0) {
+            av_freep(&pad.name);
+            return AVERROR(ENOMEM);
+        }
+    }
+
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    LV2Context *s = ctx->priv;
+    AVFilterFormats *formats;
+    AVFilterChannelLayouts *layouts;
+    AVFilterLink *outlink = ctx->outputs[0];
+    static const enum AVSampleFormat sample_fmts[] = {
+        AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
+    int 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;
+
+    if (s->nb_inputs) {
+        formats = ff_all_samplerates();
+        if (!formats)
+            return AVERROR(ENOMEM);
+
+        ret = ff_set_common_samplerates(ctx, formats);
+        if (ret < 0)
+            return ret;
+    } else {
+        int sample_rates[] = { s->sample_rate, -1 };
+
+        ret = ff_set_common_samplerates(ctx, ff_make_format_list(sample_rates));
+        if (ret < 0)
+            return ret;
+    }
+
+    if (s->nb_inputs == 2 && s->nb_outputs == 2) {
+        layouts = NULL;
+        ret = ff_add_channel_layout(&layouts, AV_CH_LAYOUT_STEREO);
+        if (ret < 0)
+            return ret;
+        ret = ff_set_common_channel_layouts(ctx, layouts);
+        if (ret < 0)
+            return ret;
+    } else {
+        if (s->nb_inputs >= 1) {
+            AVFilterLink *inlink = ctx->inputs[0];
+            uint64_t inlayout = FF_COUNT2LAYOUT(s->nb_inputs);
+
+            layouts = NULL;
+            ret = ff_add_channel_layout(&layouts, inlayout);
+            if (ret < 0)
+                return ret;
+            ret = ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
+            if (ret < 0)
+                return ret;
+
+            if (!s->nb_outputs) {
+                ret = ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);
+                if (ret < 0)
+                    return ret;
+            }
+        }
+
+        if (s->nb_outputs >= 1) {
+            uint64_t outlayout = FF_COUNT2LAYOUT(s->nb_outputs);
+
+            layouts = NULL;
+            ret = ff_add_channel_layout(&layouts, outlayout);
+            if (ret < 0)
+                return ret;
+            ret = ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);
+            if (ret < 0)
+                return ret;
+        }
+    }
+
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    LV2Context *s = ctx->priv;
+
+    lilv_node_free(s->powerOf2BlockLength);
+    lilv_node_free(s->fixedBlockLength);
+    lilv_node_free(s->boundedBlockLength);
+    lilv_node_free(s->urid_map);
+    lilv_node_free(s->atom_Sequence);
+    lilv_node_free(s->atom_AtomPort);
+    lilv_node_free(s->lv2_Optional);
+    lilv_node_free(s->lv2_ControlPort);
+    lilv_node_free(s->lv2_AudioPort);
+    lilv_node_free(s->lv2_OutputPort);
+    lilv_node_free(s->lv2_InputPort);
+    uri_table_destroy(&s->uri_table);
+    lilv_instance_free(s->instance);
+    lilv_world_free(s->world);
+    av_freep(&s->mins);
+    av_freep(&s->maxes);
+    av_freep(&s->controls);
+    av_freep(&s->seq_out);
+
+    if (ctx->nb_inputs)
+        av_freep(&ctx->input_pads[0].name);
+}
+
+static const AVFilterPad lv2_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_AUDIO,
+        .config_props  = config_output,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+AVFilter ff_af_lv2 = {
+    .name          = "lv2",
+    .description   = NULL_IF_CONFIG_SMALL("Apply LV2 effect."),
+    .priv_size     = sizeof(LV2Context),
+    .priv_class    = &lv2_class,
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = 0,
+    .outputs       = lv2_outputs,
+    .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
+};
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index e09d841387..4c834f7381 100644
--- a/libavfilter/allfilters.c
+++ b/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);
diff --git a/libavfilter/version.h b/libavfilter/version.h
index fdcf76befe..1d356a9a5a 100644
--- a/libavfilter/version.h
+++ b/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, \