text: /*
   * 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/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->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, ret;
  
      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 ((ret = ff_append_inpad_free_name(ctx, &pad)) < 0)
              return ret;
      }
  
      return 0;
  }
  
  static int query_formats(AVFilterContext *ctx)
  {
      LV2Context *s = ctx->priv;
      AVFilterChannelLayouts *layouts;
      AVFilterLink *outlink = ctx->outputs[0];
      static const enum AVSampleFormat sample_fmts[] = {
          AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
      int ret = ff_set_common_formats_from_list(ctx, sample_fmts);
      if (ret < 0)
          return ret;
  
      if (s->nb_inputs) {
          ret = ff_set_common_all_samplerates(ctx);
          if (ret < 0)
              return ret;
      } else {
          int sample_rates[] = { s->sample_rate, -1 };
  
          ret = ff_set_common_samplerates_from_list(ctx, 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->outcfg.channel_layouts);
              if (ret < 0)
                  return ret;
  
              if (!s->nb_outputs) {
                  ret = ff_channel_layouts_ref(layouts, &outlink->incfg.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->incfg.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);
  }
  
  static const AVFilterPad lv2_outputs[] = {
      {
          .name          = "default",
          .type          = AVMEDIA_TYPE_AUDIO,
          .config_props  = config_output,
          .request_frame = request_frame,
      },
  };
  
  const 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,
      .inputs        = 0,
      FILTER_OUTPUTS(lv2_outputs),
      FILTER_QUERY_FUNC(query_formats),
      .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
  };
  