/*
  * 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;

     void (*filter)(void **dst, void **prv, const void **src,
                    int nb_samples, int channels, float mult, int clip);

 } CrystalizerContext;
 
 #define OFFSET(x) offsetof(CrystalizerContext, x)
 #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 
 static const AVOption crystalizer_options[] = {
     { "i", "set intensity",    OFFSET(mult), AV_OPT_TYPE_FLOAT, {.dbl=2.0}, 0, 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);
 }
 

 static void filter_flt(void **d, void **p, const void **s,
                        int nb_samples, int channels,
                        float mult, int clip)
 {
     const float *src = s[0];
     float *dst = d[0];
     float *prv = p[0];
     int n, c;
 
     for (n = 0; n < nb_samples; n++) {
         for (c = 0; c < channels; c++) {
             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 += c;
         src += c;
     }
 }
 
 static void filter_dbl(void **d, void **p, const void **s,
                        int nb_samples, int channels,
                        float mult, int clip)
 {
     const double *src = s[0];
     double *dst = d[0];
     double *prv = p[0];
     int n, c;
 
     for (n = 0; n < nb_samples; n++) {
         for (c = 0; c < channels; c++) {
             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 += c;
         src += c;
     }
 }
 
 static void filter_fltp(void **d, void **p, const void **s,
                         int nb_samples, int channels,
                         float mult, int clip)
 {
     int n, c;
 
     for (c = 0; c < channels; 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);
             }
         }
     }
 }
 
 static void filter_dblp(void **d, void **p, const void **s,
                         int nb_samples, int channels,
                         float mult, int clip)
 {
     int n, c;
 
     for (c = 0; c < channels; 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);
             }
         }
     }
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;

     CrystalizerContext *s = ctx->priv;

 
     switch (inlink->format) {
     case AV_SAMPLE_FMT_FLT:  s->filter = filter_flt;  break;
     case AV_SAMPLE_FMT_DBL:  s->filter = filter_dbl;  break;
     case AV_SAMPLE_FMT_FLTP: s->filter = filter_fltp; break;
     case AV_SAMPLE_FMT_DBLP: s->filter = filter_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;
 
     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);
     }
 

     s->filter((void **)out->extended_data, (void **)s->prev->extended_data, (const void **)in->extended_data,
               in->nb_samples, in->channels, s->mult, s->clip);

 
     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 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 expand audio dynamic range filter."),
     .query_formats  = query_formats,
     .priv_size      = sizeof(CrystalizerContext),
     .priv_class     = &crystalizer_class,
     .uninit         = uninit,
     .inputs         = inputs,
     .outputs        = outputs,
 };