text: /*
   * Copyright (c) 2016 The FFmpeg Project
   *
   * 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
   */
  
  #include "libavutil/channel_layout.h"
  #include "libavutil/opt.h"
  #include "avfilter.h"
  #include "audio.h"
  #include "formats.h"
  
  typedef struct CrystalizerContext {
      const AVClass *class;
      float mult;
      int clip;
      AVFrame *prev;
      int (*filter)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
  } CrystalizerContext;
  
  #define OFFSET(x) offsetof(CrystalizerContext, x)
  #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
  
  static const AVOption crystalizer_options[] = {
      { "i", "set intensity",    OFFSET(mult), AV_OPT_TYPE_FLOAT, {.dbl=2.0},-10, 10, A },
      { "c", "enable clipping",  OFFSET(clip), AV_OPT_TYPE_BOOL,  {.i64=1},   0,  1, A },
      { NULL }
  };
  
  AVFILTER_DEFINE_CLASS(crystalizer);
  
  static int query_formats(AVFilterContext *ctx)
  {
      AVFilterFormats *formats = NULL;
      AVFilterChannelLayouts *layouts = NULL;
      static const enum AVSampleFormat sample_fmts[] = {
          AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLTP,
          AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBLP,
          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;
  
      layouts = ff_all_channel_counts();
      if (!layouts)
          return AVERROR(ENOMEM);
  
      ret = ff_set_common_channel_layouts(ctx, layouts);
      if (ret < 0)
          return ret;
  
      formats = ff_all_samplerates();
      return ff_set_common_samplerates(ctx, formats);
  }
  
  typedef struct ThreadData {
      void **d;
      void **p;
      const void **s;
      int nb_samples;
      int channels;
      float mult;
      int clip;
  } ThreadData;
  
  static int filter_flt(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      const float mult = td->mult;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      float *prv = p[0];
      int n, c;
  
      for (c = start; c < end; c++) {
          const float *src = s[0];
          float *dst = d[0];
  
          for (n = 0; n < nb_samples; n++) {
              float current = src[c];
              dst[c] = current + (current - prv[c]) * mult;
              prv[c] = current;
              if (clip) {
                  dst[c] = av_clipf(dst[c], -1, 1);
              }
  
              dst += channels;
              src += channels;
          }
      }
  
      return 0;
  }
  
  static int filter_dbl(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      double mult = td->mult;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      double *prv = p[0];
      int n, c;
  
      for (c = start; c < end; c++) {
          const double *src = s[0];
          double *dst = d[0];
  
          for (n = 0; n < nb_samples; n++) {
              double current = src[c];
  
              dst[c] = current + (current - prv[c]) * mult;
              prv[c] = current;
              if (clip) {
                  dst[c] = av_clipd(dst[c], -1, 1);
              }
  
              dst += channels;
              src += channels;
          }
      }
  
      return 0;
  }
  
  static int filter_fltp(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      float mult = td->mult;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      int n, c;
  
      for (c = start; c < end; c++) {
          const float *src = s[c];
          float *dst = d[c];
          float *prv = p[c];
  
          for (n = 0; n < nb_samples; n++) {
              float current = src[n];
  
              dst[n] = current + (current - prv[0]) * mult;
              prv[0] = current;
              if (clip) {
                  dst[n] = av_clipf(dst[n], -1, 1);
              }
          }
      }
  
      return 0;
  }
  
  static int filter_dblp(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      const double mult = td->mult;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      int n, c;
  
      for (c = start; c < end; c++) {
          const double *src = s[c];
          double *dst = d[c];
          double *prv = p[c];
  
          for (n = 0; n < nb_samples; n++) {
              double current = src[n];
  
              dst[n] = current + (current - prv[0]) * mult;
              prv[0] = current;
              if (clip) {
                  dst[n] = av_clipd(dst[n], -1, 1);
              }
          }
      }
  
      return 0;
  }
  
  static int ifilter_flt(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      const float mult = -td->mult;
      const float div = -td->mult + 1.f;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      float *prv = p[0];
      int n, c;
  
      for (c = start; c < end; c++) {
          const float *src = s[0];
          float *dst = d[0];
  
          for (n = 0; n < nb_samples; n++) {
              float current = src[c];
              dst[c] = (current + prv[c] * mult) / div;
              prv[c] = dst[c];
              if (clip) {
                  dst[c] = av_clipf(dst[c], -1, 1);
              }
  
              dst += channels;
              src += channels;
          }
      }
  
      return 0;
  }
  
  static int ifilter_dbl(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      const double mult = -td->mult;
      const double div = -td->mult + 1.f;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      double *prv = p[0];
      int n, c;
  
      for (c = start; c < end; c++) {
          const double *src = s[0];
          double *dst = d[0];
  
          for (n = 0; n < nb_samples; n++) {
              double current = src[c];
  
              dst[c] = (current + prv[c] * mult) / div;
              prv[c] = dst[c];
              if (clip) {
                  dst[c] = av_clipd(dst[c], -1, 1);
              }
  
              dst += channels;
              src += channels;
          }
      }
  
      return 0;
  }
  
  static int ifilter_fltp(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      const float mult = -td->mult;
      const float div = -td->mult + 1.f;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      int n, c;
  
      for (c = start; c < end; c++) {
          const float *src = s[c];
          float *dst = d[c];
          float *prv = p[c];
  
          for (n = 0; n < nb_samples; n++) {
              float current = src[n];
  
              dst[n] = (current + prv[0] * mult) / div;
              prv[0] = dst[n];
              if (clip) {
                  dst[n] = av_clipf(dst[n], -1, 1);
              }
          }
      }
  
      return 0;
  }
  
  static int ifilter_dblp(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
  {
      ThreadData *td = arg;
      void **d = td->d;
      void **p = td->p;
      const void **s = td->s;
      const int nb_samples = td->nb_samples;
      const int channels = td->channels;
      const double mult = -td->mult;
      const double div = -td->mult + 1.f;
      const int clip = td->clip;
      const int start = (channels * jobnr) / nb_jobs;
      const int end = (channels * (jobnr+1)) / nb_jobs;
      int n, c;
  
      for (c = start; c < end; c++) {
          const double *src = s[c];
          double *dst = d[c];
          double *prv = p[c];
  
          for (n = 0; n < nb_samples; n++) {
              double current = src[n];
  
              dst[n] = (current + prv[0] * mult) / div;
              prv[0] = dst[n];
              if (clip) {
                  dst[n] = av_clipd(dst[n], -1, 1);
              }
          }
      }
  
      return 0;
  }
  
  static int config_input(AVFilterLink *inlink)
  {
      AVFilterContext *ctx = inlink->dst;
      CrystalizerContext *s = ctx->priv;
  
      switch (inlink->format) {
      case AV_SAMPLE_FMT_FLT:  s->filter = s->mult >= 0.f ? filter_flt  : ifilter_flt;  break;
      case AV_SAMPLE_FMT_DBL:  s->filter = s->mult >= 0.f ? filter_dbl  : ifilter_dbl;  break;
      case AV_SAMPLE_FMT_FLTP: s->filter = s->mult >= 0.f ? filter_fltp : ifilter_fltp; break;
      case AV_SAMPLE_FMT_DBLP: s->filter = s->mult >= 0.f ? filter_dblp : ifilter_dblp; break;
      }
  
      return 0;
  }
  
  static int filter_frame(AVFilterLink *inlink, AVFrame *in)
  {
      AVFilterContext *ctx = inlink->dst;
      AVFilterLink *outlink = ctx->outputs[0];
      CrystalizerContext *s = ctx->priv;
      AVFrame *out;
      ThreadData td;
  
      if (!s->prev) {
          s->prev = ff_get_audio_buffer(inlink, 1);
          if (!s->prev) {
              av_frame_free(&in);
              return AVERROR(ENOMEM);
          }
      }
  
      if (av_frame_is_writable(in)) {
          out = in;
      } else {
          out = ff_get_audio_buffer(outlink, in->nb_samples);
          if (!out) {
              av_frame_free(&in);
              return AVERROR(ENOMEM);
          }
          av_frame_copy_props(out, in);
      }
  
      td.d = (void **)out->extended_data;
      td.s = (const void **)in->extended_data;
      td.p = (void **)s->prev->extended_data;
      td.nb_samples = in->nb_samples;
      td.channels = in->channels;
      td.mult = ctx->is_disabled ? 0.f : s->mult;
      td.clip = s->clip;
      ctx->internal->execute(ctx, s->filter, &td, NULL, FFMIN(inlink->channels,
                                                              ff_filter_get_nb_threads(ctx)));
  
      if (out != in)
          av_frame_free(&in);
  
      return ff_filter_frame(outlink, out);
  }
  
  static av_cold void uninit(AVFilterContext *ctx)
  {
      CrystalizerContext *s = ctx->priv;
  
      av_frame_free(&s->prev);
  }
  
  static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                             char *res, int res_len, int flags)
  {
      int ret;
  
      ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
      if (ret < 0)
          return ret;
  
      return config_input(ctx->inputs[0]);
  }
  
  static const AVFilterPad inputs[] = {
      {
          .name         = "default",
          .type         = AVMEDIA_TYPE_AUDIO,
          .filter_frame = filter_frame,
          .config_props = config_input,
      },
      { NULL }
  };
  
  static const AVFilterPad outputs[] = {
      {
          .name = "default",
          .type = AVMEDIA_TYPE_AUDIO,
      },
      { NULL }
  };
  
  AVFilter ff_af_crystalizer = {
      .name           = "crystalizer",
      .description    = NULL_IF_CONFIG_SMALL("Simple audio noise sharpening filter."),
      .query_formats  = query_formats,
      .priv_size      = sizeof(CrystalizerContext),
      .priv_class     = &crystalizer_class,
      .uninit         = uninit,
      .inputs         = inputs,
      .outputs        = outputs,
      .process_command = process_command,
      .flags          = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
                        AVFILTER_FLAG_SLICE_THREADS,
  };
  