/*
  * 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 int set_control(AVFilterContext *ctx, unsigned long port, LADSPA_Data value)
 {
     LADSPAContext *s = ctx->priv;
     const char *label = s->desc->Label;
     LADSPA_PortRangeHint *h = (LADSPA_PortRangeHint *)s->desc->PortRangeHints +
                               s->icmap[port];
 
     if (port >= s->nb_inputcontrols) {
         av_log(ctx, AV_LOG_ERROR, "Control c%ld is out of range [0 - %lu].\n",
                port, s->nb_inputcontrols);
         return AVERROR(EINVAL);
     }
 
     if (LADSPA_IS_HINT_BOUNDED_BELOW(h->HintDescriptor) &&
             value < h->LowerBound) {
         av_log(ctx, AV_LOG_ERROR,
                 "%s: input control c%ld is below lower boundary of %0.4f.\n",
                 label, port, h->LowerBound);
         return AVERROR(EINVAL);
     }
 
     if (LADSPA_IS_HINT_BOUNDED_ABOVE(h->HintDescriptor) &&
             value > h->UpperBound) {
         av_log(ctx, AV_LOG_ERROR,
                 "%s: input control c%ld is above upper boundary of %0.4f.\n",
                 label, port, h->UpperBound);
         return AVERROR(EINVAL);
     }
 
     s->ictlv[port] = value;
 
     return 0;
 }
 

 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_Data val;

         int ret;

 
         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 ((ret = set_control(ctx, i, val)) < 0)
             return ret;

         s->ctl_needs_value[i] = 0;
     }
 
     // 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 {

         AVFilterLink *outlink = ctx->outputs[0];
 

         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)
                 ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);

         }
 
         if (s->nb_outputs >= 1) {
             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 int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                            char *res, int res_len, int flags)
 {
     LADSPA_Data value;
     unsigned long port;
 
     if (sscanf(cmd, "c%ld", &port) + sscanf(args, "%f", &value) != 2)
         return AVERROR(EINVAL);
 
     return set_control(ctx, port, value);
 }
 

 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,

     .process_command = process_command,

     .inputs        = 0,
     .outputs       = ladspa_outputs,
     .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
 };