avfilter: add ladspa wrapper filter

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

1 files changed, 673 insertions, 0 deletions

diff --git a/libavfilter/af_ladspa.c b/libavfilter/af_ladspa.c
new file mode 100644
index 0000000000..d1e3e23721
--- /dev/null
+++ b/libavfilter/af_ladspa.c
@@ -0,0 +1,673 @@
+/*
+ * Copyright (c) 2013 Paul B Mahol
+ * Copyright (c) 2011 Mina Nagy Zaki
+ *
+ * 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
+ * LADSPA wrapper
+ */
+
+#include <dlfcn.h>
+#include <ladspa.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 LADSPAContext {
+    const AVClass *class;
+    char *dl_name;
+    char *plugin;
+    char *options;
+    void *dl_handle;
+
+    unsigned long nb_inputs;
+    unsigned long *ipmap;      /* map input number to port number */
+
+    unsigned long nb_inputcontrols;
+    unsigned long *icmap;      /* map input control number to port number */
+    LADSPA_Data *ictlv;        /* input controls values */
+
+    unsigned long nb_outputs;
+    unsigned long *opmap;      /* map output number to port number */
+
+    unsigned long nb_outputcontrols;
+    unsigned long *ocmap;      /* map output control number to port number */
+    LADSPA_Data *octlv;        /* output controls values */
+
+    const LADSPA_Descriptor *desc;
+    int *ctl_needs_value;
+    int nb_handles;
+    LADSPA_Handle *handles;
+
+    int sample_rate;
+    int nb_samples;
+    int64_t pts;
+    int64_t duration;
+} LADSPAContext;
+
+#define OFFSET(x) offsetof(LADSPAContext, x)
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption ladspa_options[] = {
+    { "file", "set library name or full path", OFFSET(dl_name), AV_OPT_TYPE_STRING, .flags = FLAGS },
+    { "f",    "set library name or full path", OFFSET(dl_name), AV_OPT_TYPE_STRING, .flags = FLAGS },
+    { "plugin", "set plugin name", OFFSET(plugin), AV_OPT_TYPE_STRING, .flags = FLAGS },
+    { "p",      "set plugin name", OFFSET(plugin), 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(ladspa);
+
+static void print_ctl_info(AVFilterContext *ctx, int level,
+                           LADSPAContext *s, int ctl, unsigned long *map,
+                           LADSPA_Data *values, int print)
+{
+    const LADSPA_PortRangeHint *h = s->desc->PortRangeHints + map[ctl];
+
+    av_log(ctx, level, "c%i: %s [", ctl, s->desc->PortNames[map[ctl]]);
+
+    if (LADSPA_IS_HINT_TOGGLED(h->HintDescriptor)) {
+        av_log(ctx, level, "toggled (1 or 0)");
+
+        if (LADSPA_IS_HINT_HAS_DEFAULT(h->HintDescriptor))
+            av_log(ctx, level, " (default %i)", (int)values[ctl]);
+    } else {
+        if (LADSPA_IS_HINT_INTEGER(h->HintDescriptor)) {
+            av_log(ctx, level, "<int>");
+
+            if (LADSPA_IS_HINT_BOUNDED_BELOW(h->HintDescriptor))
+                av_log(ctx, level, ", min: %i", (int)h->LowerBound);
+
+            if (LADSPA_IS_HINT_BOUNDED_ABOVE(h->HintDescriptor))
+                av_log(ctx, level, ", max: %i", (int)h->UpperBound);
+
+            if (print)
+                av_log(ctx, level, " (value %d)", (int)values[ctl]);
+            else if (LADSPA_IS_HINT_HAS_DEFAULT(h->HintDescriptor))
+                av_log(ctx, level, " (default %d)", (int)values[ctl]);
+        } else {
+            av_log(ctx, level, "<float>");
+
+            if (LADSPA_IS_HINT_BOUNDED_BELOW(h->HintDescriptor))
+                av_log(ctx, level, ", min: %f", h->LowerBound);
+
+            if (LADSPA_IS_HINT_BOUNDED_ABOVE(h->HintDescriptor))
+                av_log(ctx, level, ", max: %f", h->UpperBound);
+
+            if (print)
+                av_log(ctx, level, " (value %f)", values[ctl]);
+            else if (LADSPA_IS_HINT_HAS_DEFAULT(h->HintDescriptor))
+                av_log(ctx, level, " (default %f)", values[ctl]);
+        }
+
+        if (LADSPA_IS_HINT_SAMPLE_RATE(h->HintDescriptor))
+            av_log(ctx, level, ", multiple of sample rate");
+
+        if (LADSPA_IS_HINT_LOGARITHMIC(h->HintDescriptor))
+            av_log(ctx, level, ", logarithmic scale");
+    }
+
+    av_log(ctx, level, "]\n");
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    LADSPAContext *s = ctx->priv;
+    AVFrame *out;
+    int i, h;
+
+    if (!s->nb_outputs ||
+        (av_frame_is_writable(in) && s->nb_inputs == s->nb_outputs &&
+        !(s->desc->Properties & LADSPA_PROPERTY_INPLACE_BROKEN))) {
+        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);
+    }
+
+    for (h = 0; h < s->nb_handles; h++) {
+        for (i = 0; i < s->nb_inputs; i++) {
+            s->desc->connect_port(s->handles[h], s->ipmap[i],
+                                  (LADSPA_Data*)in->extended_data[i]);
+        }
+
+        for (i = 0; i < s->nb_outputs; i++) {
+            s->desc->connect_port(s->handles[h], s->opmap[i],
+                                  (LADSPA_Data*)out->extended_data[i]);
+        }
+
+        s->desc->run(s->handles[h], in->nb_samples);
+    }
+
+    for (i = 0; i < s->nb_outputcontrols; i++)
+        print_ctl_info(ctx, AV_LOG_VERBOSE, s, i, s->ocmap, s->octlv, 1);
+
+    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;
+    LADSPAContext *s = ctx->priv;
+    AVFrame *out;
+    int64_t t;
+    int i;
+
+    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);
+
+    for (i = 0; i < s->nb_outputs; i++)
+        s->desc->connect_port(s->handles[0], s->opmap[i],
+                (LADSPA_Data*)out->extended_data[i]);
+
+    s->desc->run(s->handles[0], s->nb_samples);
+
+    for (i = 0; i < s->nb_outputcontrols; i++)
+        print_ctl_info(ctx, AV_LOG_INFO, s, i, s->ocmap, s->octlv, 1);
+
+    out->sample_rate = s->sample_rate;
+    out->pts         = s->pts;
+    s->pts          += s->nb_samples;
+
+    return ff_filter_frame(outlink, out);
+}
+
+static void set_default_ctl_value(LADSPAContext *s, int ctl,
+                                  unsigned long *map, LADSPA_Data *values)
+{
+    const LADSPA_PortRangeHint *h = s->desc->PortRangeHints + map[ctl];
+    const LADSPA_Data lower = h->LowerBound;
+    const LADSPA_Data upper = h->UpperBound;
+
+    if (LADSPA_IS_HINT_DEFAULT_MINIMUM(h->HintDescriptor)) {
+        values[ctl] = lower;
+    } else if (LADSPA_IS_HINT_DEFAULT_MAXIMUM(h->HintDescriptor)) {
+        values[ctl] = upper;
+    } else if (LADSPA_IS_HINT_DEFAULT_0(h->HintDescriptor)) {
+        values[ctl] = 0.0;
+    } else if (LADSPA_IS_HINT_DEFAULT_1(h->HintDescriptor)) {
+        values[ctl] = 1.0;
+    } else if (LADSPA_IS_HINT_DEFAULT_100(h->HintDescriptor)) {
+        values[ctl] = 100.0;
+    } else if (LADSPA_IS_HINT_DEFAULT_440(h->HintDescriptor)) {
+        values[ctl] = 440.0;
+    } else if (LADSPA_IS_HINT_DEFAULT_LOW(h->HintDescriptor)) {
+        if (LADSPA_IS_HINT_LOGARITHMIC(h->HintDescriptor))
+            values[ctl] = exp(log(lower) * 0.75 + log(upper) * 0.25);
+        else
+            values[ctl] = lower * 0.75 + upper * 0.25;
+    } else if (LADSPA_IS_HINT_DEFAULT_MIDDLE(h->HintDescriptor)) {
+        if (LADSPA_IS_HINT_LOGARITHMIC(h->HintDescriptor))
+            values[ctl] = exp(log(lower) * 0.5 + log(upper) * 0.5);
+        else
+            values[ctl] = lower * 0.5 + upper * 0.5;
+    } else if (LADSPA_IS_HINT_DEFAULT_HIGH(h->HintDescriptor)) {
+        if (LADSPA_IS_HINT_LOGARITHMIC(h->HintDescriptor))
+            values[ctl] = exp(log(lower) * 0.25 + log(upper) * 0.75);
+        else
+            values[ctl] = lower * 0.25 + upper * 0.75;
+    }
+}
+
+static int connect_ports(AVFilterContext *ctx, AVFilterLink *link)
+{
+    LADSPAContext *s = ctx->priv;
+    int i, j;
+
+    s->nb_handles = s->nb_inputs == 1 && s->nb_outputs == 1 ? link->channels : 1;
+    s->handles    = av_calloc(s->nb_handles, sizeof(*s->handles));
+    if (!s->handles)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < s->nb_handles; i++) {
+        s->handles[i] = s->desc->instantiate(s->desc, link->sample_rate);
+        if (!s->handles[i]) {
+            av_log(ctx, AV_LOG_ERROR, "Could not instantiate plugin.\n");
+            return AVERROR_EXTERNAL;
+        }
+
+        // Connect the input control ports
+        for (j = 0; j < s->nb_inputcontrols; j++)
+            s->desc->connect_port(s->handles[i], s->icmap[j], s->ictlv + j);
+
+        // Connect the output control ports
+        for (j = 0; j < s->nb_outputcontrols; j++)
+            s->desc->connect_port(s->handles[i], s->ocmap[j], &s->octlv[j]);
+
+        if (s->desc->activate)
+            s->desc->activate(s->handles[i]);
+    }
+
+    av_log(ctx, AV_LOG_DEBUG, "handles: %d\n", s->nb_handles);
+
+    return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+
+    return connect_ports(ctx, inlink);
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    int ret;
+
+    if (ctx->nb_inputs) {
+        AVFilterLink *inlink = ctx->inputs[0];
+
+        outlink->format      = inlink->format;
+        outlink->sample_rate = inlink->sample_rate;
+
+        ret = 0;
+    } else {
+        LADSPAContext *s = ctx->priv;
+
+        outlink->sample_rate = s->sample_rate;
+        outlink->time_base   = (AVRational){1, s->sample_rate};
+
+        ret = connect_ports(ctx, outlink);
+    }
+
+    return ret;
+}
+
+static void count_ports(const LADSPA_Descriptor *desc,
+                        unsigned long *nb_inputs, unsigned long *nb_outputs)
+{
+    LADSPA_PortDescriptor pd;
+    int i;
+
+    for (i = 0; i < desc->PortCount; i++) {
+        pd = desc->PortDescriptors[i];
+
+        if (LADSPA_IS_PORT_AUDIO(pd)) {
+            if (LADSPA_IS_PORT_INPUT(pd)) {
+                (*nb_inputs)++;
+            } else if (LADSPA_IS_PORT_OUTPUT(pd)) {
+                (*nb_outputs)++;
+            }
+        }
+    }
+}
+
+static void *try_load(const char *dir, const char *soname)
+{
+    char *path = av_asprintf("%s/%s.so", dir, soname);
+    void *ret = NULL;
+
+    if (path) {
+        ret = dlopen(path, RTLD_LOCAL|RTLD_NOW);
+        av_free(path);
+    }
+
+    return ret;
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    LADSPAContext *s = ctx->priv;
+    LADSPA_Descriptor_Function descriptor_fn;
+    const LADSPA_Descriptor *desc;
+    LADSPA_PortDescriptor pd;
+    AVFilterPad pad = { NULL };
+    char *p, *arg, *saveptr = NULL;
+    unsigned long nb_ports;
+    int i;
+
+    if (!s->dl_name) {
+        av_log(ctx, AV_LOG_ERROR, "No plugin name provided\n");
+        return AVERROR(EINVAL);
+    }
+
+    if (s->dl_name[0] == '/' || s->dl_name[0] == '.') {
+        // argument is a path
+        s->dl_handle = dlopen(s->dl_name, RTLD_LOCAL|RTLD_NOW);
+    } else {
+        // argument is a shared object name
+        char *paths = av_strdup(getenv("LADSPA_PATH"));
+        const char *separator = ":";
+
+        if (paths) {
+            p = paths;
+            while ((arg = av_strtok(p, separator, &saveptr)) && !s->dl_handle) {
+                s->dl_handle = try_load(arg, s->dl_name);
+                p = NULL;
+            }
+        }
+
+        av_free(paths);
+        if (!s->dl_handle && (paths = av_asprintf("%s/.ladspa/lib", getenv("HOME")))) {
+            s->dl_handle = try_load(paths, s->dl_name);
+            av_free(paths);
+        }
+
+        if (!s->dl_handle)
+            s->dl_handle = try_load("/usr/local/lib/ladspa", s->dl_name);
+
+        if (!s->dl_handle)
+            s->dl_handle = try_load("/usr/lib/ladspa", s->dl_name);
+    }
+    if (!s->dl_handle) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to load '%s'\n", s->dl_name);
+        return AVERROR(EINVAL);
+    }
+
+    descriptor_fn = dlsym(s->dl_handle, "ladspa_descriptor");
+    if (!descriptor_fn) {
+        av_log(ctx, AV_LOG_ERROR, "Could not find ladspa_descriptor: %s\n", dlerror());
+        return AVERROR(EINVAL);
+    }
+
+    // Find the requested plugin, or list plugins
+    if (!s->plugin) {
+        av_log(ctx, AV_LOG_INFO, "The '%s' library contains the following plugins:\n", s->dl_name);
+        av_log(ctx, AV_LOG_INFO, "I = Input Channels\n");
+        av_log(ctx, AV_LOG_INFO, "O = Output Channels\n");
+        av_log(ctx, AV_LOG_INFO, "I:O %-25s %s\n", "Plugin", "Description");
+        av_log(ctx, AV_LOG_INFO, "\n");
+        for (i = 0; desc = descriptor_fn(i); i++) {
+            unsigned long inputs = 0, outputs = 0;
+
+            count_ports(desc, &inputs, &outputs);
+            av_log(ctx, AV_LOG_INFO, "%lu:%lu %-25s %s\n", inputs, outputs, desc->Label,
+                                     av_x_if_null(desc->Name, "?"));
+            av_log(ctx, AV_LOG_VERBOSE, "Maker: %s\n", av_x_if_null(desc->Maker, "?"));
+            av_log(ctx, AV_LOG_VERBOSE, "Copyright: %s\n", av_x_if_null(desc->Copyright, "?"));
+        }
+        return AVERROR_EXIT;
+    } else {
+        for (i = 0;; i++) {
+            desc = descriptor_fn(i);
+            if (!desc) {
+                av_log(ctx, AV_LOG_ERROR, "Could not find plugin: %s\n", s->plugin);
+                return AVERROR(EINVAL);
+            }
+
+            if (desc->Label && !strcmp(desc->Label, s->plugin))
+                break;
+        }
+    }
+
+    s->desc  = desc;
+    nb_ports = desc->PortCount;
+
+    s->ipmap = av_calloc(nb_ports, sizeof(*s->ipmap));
+    s->opmap = av_calloc(nb_ports, sizeof(*s->opmap));
+    s->icmap = av_calloc(nb_ports, sizeof(*s->icmap));
+    s->ocmap = av_calloc(nb_ports, sizeof(*s->ocmap));
+    s->ictlv = av_calloc(nb_ports, sizeof(*s->ictlv));
+    s->octlv = av_calloc(nb_ports, sizeof(*s->octlv));
+    s->ctl_needs_value = av_calloc(nb_ports, sizeof(*s->ctl_needs_value));
+    if (!s->ipmap || !s->opmap || !s->icmap ||
+        !s->ocmap || !s->ictlv || !s->octlv || !s->ctl_needs_value)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < nb_ports; i++) {
+        pd = desc->PortDescriptors[i];
+
+        if (LADSPA_IS_PORT_AUDIO(pd)) {
+            if (LADSPA_IS_PORT_INPUT(pd)) {
+                s->ipmap[s->nb_inputs] = i;
+                s->nb_inputs++;
+            } else if (LADSPA_IS_PORT_OUTPUT(pd)) {
+                s->opmap[s->nb_outputs] = i;
+                s->nb_outputs++;
+            }
+        } else if (LADSPA_IS_PORT_CONTROL(pd)) {
+            if (LADSPA_IS_PORT_INPUT(pd)) {
+                s->icmap[s->nb_inputcontrols] = i;
+
+                if (LADSPA_IS_HINT_HAS_DEFAULT(desc->PortRangeHints[i].HintDescriptor))
+                    set_default_ctl_value(s, s->nb_inputcontrols, s->icmap, s->ictlv);
+                else
+                    s->ctl_needs_value[s->nb_inputcontrols] = 1;
+
+                s->nb_inputcontrols++;
+            } else if (LADSPA_IS_PORT_OUTPUT(pd)) {
+                s->ocmap[s->nb_outputcontrols] = i;
+                s->nb_outputcontrols++;
+            }
+        }
+    }
+
+    // List Control Ports if "help" is specified
+    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",
+                   desc->Label);
+        } else {
+            av_log(ctx, AV_LOG_INFO,
+                   "The '%s' plugin has the following input controls:\n",
+                   desc->Label);
+            for (i = 0; i < s->nb_inputcontrols; i++)
+                print_ctl_info(ctx, AV_LOG_INFO, s, i, s->icmap, s->ictlv, 0);
+        }
+        return AVERROR_EXIT;
+    }
+
+    // Parse control parameters
+    p = s->options;
+    while (s->options) {
+        LADSPA_PortRangeHint *h;
+        LADSPA_Data val;
+
+        if (!(arg = av_strtok(p, "|", &saveptr)))
+            break;
+        p = NULL;
+
+        if (sscanf(arg, "c%d=%f", &i, &val) != 2) {
+            av_log(ctx, AV_LOG_ERROR, "Invalid syntax.\n");
+            return AVERROR(EINVAL);
+        }
+
+        if (i < 0 || i >= s->nb_inputcontrols) {
+            av_log(ctx, AV_LOG_ERROR,
+                   "Control c%d is out of range [0 - %lu].\n",
+                   i, s->nb_inputcontrols);
+            return AVERROR(EINVAL);
+        }
+
+        h = (LADSPA_PortRangeHint *)s->desc->PortRangeHints + s->icmap[i];
+        s->ictlv[i]           = val;
+        s->ctl_needs_value[i] = 0;
+        if (LADSPA_IS_HINT_BOUNDED_BELOW(h->HintDescriptor) &&
+                val < h->LowerBound) {
+            av_log(ctx, AV_LOG_ERROR,
+                   "%s: input control c%d is below lower boundary of %0.4f.\n",
+                   s->desc->Label, i, h->LowerBound);
+            return AVERROR(EINVAL);
+        }
+        if (LADSPA_IS_HINT_BOUNDED_ABOVE(h->HintDescriptor) &&
+                val > h->UpperBound) {
+            av_log(ctx, AV_LOG_ERROR,
+                   "%s: input control c%d is above upper boundary of %0.4f.\n",
+                   s->desc->Label, i, h->UpperBound);
+            return AVERROR(EINVAL);
+        }
+    }
+
+    // Check if any controls are not set
+    for (i = 0; i < s->nb_inputcontrols; i++) {
+        if (s->ctl_needs_value[i]) {
+            av_log(ctx, AV_LOG_ERROR, "Control c%d must be set.\n", i);
+            print_ctl_info(ctx, AV_LOG_ERROR, s, i, s->icmap, s->ictlv, 0);
+            return AVERROR(EINVAL);
+        }
+    }
+
+    pad.type = AVMEDIA_TYPE_AUDIO;
+
+    if (s->nb_inputs) {
+        pad.name = av_asprintf("in0:%s%lu", desc->Label, s->nb_inputs);
+        if (!pad.name)
+            return AVERROR(ENOMEM);
+
+        pad.filter_frame = filter_frame;
+        pad.config_props = config_input;
+        if (ff_insert_inpad(ctx, ctx->nb_inputs, &pad) < 0) {
+            av_freep(&pad.name);
+            return AVERROR(ENOMEM);
+        }
+    }
+
+    av_log(ctx, AV_LOG_DEBUG, "ports: %lu\n", nb_ports);
+    av_log(ctx, AV_LOG_DEBUG, "inputs: %lu outputs: %lu\n",
+                              s->nb_inputs, s->nb_outputs);
+    av_log(ctx, AV_LOG_DEBUG, "input controls: %lu output controls: %lu\n",
+                              s->nb_inputcontrols, s->nb_outputcontrols);
+
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    LADSPAContext *s = ctx->priv;
+    AVFilterFormats *formats;
+    AVFilterChannelLayouts *layouts;
+    static const enum AVSampleFormat sample_fmts[] = {
+        AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
+
+    formats = ff_make_format_list(sample_fmts);
+    if (!formats)
+        return AVERROR(ENOMEM);
+    ff_set_common_formats(ctx, formats);
+
+    if (s->nb_inputs) {
+        formats = ff_all_samplerates();
+        if (!formats)
+            return AVERROR(ENOMEM);
+
+        ff_set_common_samplerates(ctx, formats);
+    } else {
+        int sample_rates[] = { s->sample_rate, -1 };
+
+        ff_set_common_samplerates(ctx, ff_make_format_list(sample_rates));
+    }
+
+    if (s->nb_inputs == 1 && s->nb_outputs == 1) {
+        // We will instantiate multiple LADSPA_Handle, one over each channel
+        layouts = ff_all_channel_layouts();
+        if (!layouts)
+            return AVERROR(ENOMEM);
+
+        ff_set_common_channel_layouts(ctx, layouts);
+    } else {
+        if (s->nb_inputs >= 1) {
+            AVFilterLink *inlink = ctx->inputs[0];
+            int64_t inlayout = FF_COUNT2LAYOUT(s->nb_inputs);
+
+            layouts = NULL;
+            ff_add_channel_layout(&layouts, inlayout);
+            ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
+        }
+
+        if (s->nb_outputs >= 1) {
+            AVFilterLink *outlink = ctx->outputs[0];
+            int64_t outlayout = FF_COUNT2LAYOUT(s->nb_outputs);
+
+            layouts = NULL;
+            ff_add_channel_layout(&layouts, outlayout);
+            ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);
+        }
+    }
+
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    LADSPAContext *s = ctx->priv;
+    int i;
+
+    for (i = 0; i < s->nb_handles; i++) {
+        if (s->desc->deactivate)
+            s->desc->deactivate(s->handles[i]);
+        if (s->desc->cleanup)
+            s->desc->cleanup(s->handles[i]);
+    }
+
+    if (s->dl_handle)
+        dlclose(s->dl_handle);
+
+    av_freep(&s->ipmap);
+    av_freep(&s->opmap);
+    av_freep(&s->icmap);
+    av_freep(&s->ocmap);
+    av_freep(&s->ictlv);
+    av_freep(&s->octlv);
+    av_freep(&s->handles);
+    av_freep(&s->ctl_needs_value);
+
+    if (ctx->nb_inputs)
+        av_freep(&ctx->input_pads[0].name);
+}
+
+static const AVFilterPad ladspa_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_AUDIO,
+        .config_props  = config_output,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_af_ladspa = {
+    .name          = "ladspa",
+    .description   = NULL_IF_CONFIG_SMALL("Apply LADSPA effect."),
+    .priv_size     = sizeof(LADSPAContext),
+    .priv_class    = &ladspa_class,
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = 0,
+    .outputs       = ladspa_outputs,
+    .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
+};