/*
  * Copyright (c) 2015 Paul B Mahol
  *
  * 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/avassert.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "audio.h"
 #include "video.h"
 #include "internal.h"
 
 enum DisplayScale   { LINEAR, SQRT, CBRT, LOG, RLOG, NB_SCALES };
 enum AmplitudeScale { ALINEAR, ALOG, NB_ASCALES };
 enum SlideMode      { REPLACE, SCROLL, NB_SLIDES };
 enum DisplayMode    { SINGLE, SEPARATE, NB_DMODES };
 enum HistogramMode  { ACCUMULATE, CURRENT, NB_HMODES };
 
 typedef struct AudioHistogramContext {
     const AVClass *class;
     AVFrame *out;
     int w, h;
     AVRational frame_rate;
     uint64_t *achistogram;
     uint64_t *shistogram;
     int ascale;
     int scale;
     float phisto;
     int histogram_h;
     int apos;
     int ypos;
     int slide;
     int dmode;
     int dchannels;
     int count;
     int frame_count;
     float *combine_buffer;
     AVFrame *in[101];
     int first;
 } AudioHistogramContext;
 
 #define OFFSET(x) offsetof(AudioHistogramContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption ahistogram_options[] = {
     { "dmode", "set method to display channels", OFFSET(dmode), AV_OPT_TYPE_INT, {.i64=SINGLE}, 0, NB_DMODES-1, FLAGS, "dmode" },
         { "single", "all channels use single histogram", 0, AV_OPT_TYPE_CONST, {.i64=SINGLE},   0, 0, FLAGS, "dmode" },
         { "separate", "each channel have own histogram", 0, AV_OPT_TYPE_CONST, {.i64=SEPARATE}, 0, 0, FLAGS, "dmode" },

     { "rate", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, INT_MAX, FLAGS },
     { "r",    "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, INT_MAX, FLAGS },

     { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="hd720"}, 0, 0, FLAGS },
     { "s",    "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="hd720"}, 0, 0, FLAGS },
     { "scale", "set display scale", OFFSET(scale), AV_OPT_TYPE_INT, {.i64=LOG}, LINEAR, NB_SCALES-1, FLAGS, "scale" },
         { "log",  "logarithmic",         0, AV_OPT_TYPE_CONST, {.i64=LOG},    0, 0, FLAGS, "scale" },
         { "sqrt", "square root",         0, AV_OPT_TYPE_CONST, {.i64=SQRT},   0, 0, FLAGS, "scale" },
         { "cbrt", "cubic root",          0, AV_OPT_TYPE_CONST, {.i64=CBRT},   0, 0, FLAGS, "scale" },
         { "lin",  "linear",              0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "scale" },
         { "rlog", "reverse logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=RLOG},   0, 0, FLAGS, "scale" },
     { "ascale", "set amplitude scale", OFFSET(ascale), AV_OPT_TYPE_INT, {.i64=ALOG}, LINEAR, NB_ASCALES-1, FLAGS, "ascale" },
         { "log",  "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=ALOG},    0, 0, FLAGS, "ascale" },
         { "lin",  "linear",      0, AV_OPT_TYPE_CONST, {.i64=ALINEAR}, 0, 0, FLAGS, "ascale" },
     { "acount", "how much frames to accumulate", OFFSET(count), AV_OPT_TYPE_INT, {.i64=1}, -1, 100, FLAGS },
     { "rheight", "set histogram ratio of window height", OFFSET(phisto), AV_OPT_TYPE_FLOAT, {.dbl=0.10}, 0, 1, FLAGS },
     { "slide", "set sonogram sliding", OFFSET(slide), AV_OPT_TYPE_INT, {.i64=REPLACE}, 0, NB_SLIDES-1, FLAGS, "slide" },
         { "replace", "replace old rows with new", 0, AV_OPT_TYPE_CONST, {.i64=REPLACE},    0, 0, FLAGS, "slide" },
         { "scroll",  "scroll from top to bottom", 0, AV_OPT_TYPE_CONST, {.i64=SCROLL}, 0, 0, FLAGS, "slide" },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(ahistogram);
 
 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *formats = NULL;
     AVFilterChannelLayouts *layouts = NULL;
     AVFilterLink *inlink = ctx->inputs[0];
     AVFilterLink *outlink = ctx->outputs[0];
     static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
     static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUVA444P, AV_PIX_FMT_NONE };
     int ret = AVERROR(EINVAL);
 
     formats = ff_make_format_list(sample_fmts);
     if ((ret = ff_formats_ref         (formats, &inlink->out_formats        )) < 0 ||
         (layouts = ff_all_channel_counts()) == NULL ||
         (ret = ff_channel_layouts_ref (layouts, &inlink->out_channel_layouts)) < 0)
         return ret;
 
     formats = ff_all_samplerates();
     if ((ret = ff_formats_ref(formats, &inlink->out_samplerates)) < 0)
         return ret;
 
     formats = ff_make_format_list(pix_fmts);
     if ((ret = ff_formats_ref(formats, &outlink->in_formats)) < 0)
         return ret;
 
     return 0;
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     AudioHistogramContext *s = ctx->priv;
     int nb_samples;
 
     nb_samples = FFMAX(1024, ((double)inlink->sample_rate / av_q2d(s->frame_rate)) + 0.5);
     inlink->partial_buf_size =
     inlink->min_samples =
     inlink->max_samples = nb_samples;
 
     s->dchannels = s->dmode == SINGLE ? 1 : inlink->channels;
     s->shistogram = av_calloc(s->w, s->dchannels * sizeof(*s->shistogram));
     if (!s->shistogram)
         return AVERROR(ENOMEM);
 
     s->achistogram = av_calloc(s->w, s->dchannels * sizeof(*s->achistogram));
     if (!s->achistogram)
         return AVERROR(ENOMEM);
 
     return 0;
 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AudioHistogramContext *s = outlink->src->priv;
 
     outlink->w = s->w;
     outlink->h = s->h;
     outlink->sample_aspect_ratio = (AVRational){1,1};
     outlink->frame_rate = s->frame_rate;
 
     s->histogram_h = s->h * s->phisto;
     s->ypos = s->h * s->phisto;
 
     if (s->dmode == SEPARATE) {
         s->combine_buffer = av_malloc_array(outlink->w * 3, sizeof(*s->combine_buffer));
         if (!s->combine_buffer)
             return AVERROR(ENOMEM);
     }
 
     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;
     AVFilterLink *outlink = ctx->outputs[0];
     AudioHistogramContext *s = ctx->priv;
     const int H = s->histogram_h;
     const int w = s->w;
     int c, y, n, p, bin;

     uint64_t acmax = 1;

 
     if (!s->out || s->out->width  != outlink->w ||
                    s->out->height != outlink->h) {
         av_frame_free(&s->out);
         s->out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!s->out) {
             av_frame_free(&in);
             return AVERROR(ENOMEM);
         }
         for (n = H; n < s->h; n++) {
             memset(s->out->data[0] + n * s->out->linesize[0], 0, w);
             memset(s->out->data[1] + n * s->out->linesize[0], 127, w);
             memset(s->out->data[2] + n * s->out->linesize[0], 127, w);
             memset(s->out->data[3] + n * s->out->linesize[0], 0, w);
         }
     }
 
     if (s->dmode == SEPARATE) {
         for (y = 0; y < w; y++) {
             s->combine_buffer[3 * y    ] = 0;
             s->combine_buffer[3 * y + 1] = 127.5;
             s->combine_buffer[3 * y + 2] = 127.5;
         }
     }
 
     for (n = 0; n < H; n++) {
         memset(s->out->data[0] + n * s->out->linesize[0], 0, w);
         memset(s->out->data[1] + n * s->out->linesize[0], 127, w);
         memset(s->out->data[2] + n * s->out->linesize[0], 127, w);
         memset(s->out->data[3] + n * s->out->linesize[0], 0, w);
     }
     s->out->pts = in->pts;
 
     s->first = s->frame_count;
 
     switch (s->ascale) {
     case ALINEAR:
         for (c = 0; c < inlink->channels; c++) {
             const float *src = (const float *)in->extended_data[c];
             uint64_t *achistogram = &s->achistogram[(s->dmode == SINGLE ? 0: c) * w];
 
             for (n = 0; n < in->nb_samples; n++) {
                 bin = lrint(av_clipf(fabsf(src[n]), 0, 1) * (w - 1));
 
                 achistogram[bin]++;
             }
 
             if (s->in[s->first] && s->count >= 0) {
                 uint64_t *shistogram = &s->shistogram[(s->dmode == SINGLE ? 0: c) * w];
                 const float *src2 = (const float *)s->in[s->first]->extended_data[c];
 
                 for (n = 0; n < in->nb_samples; n++) {
                     bin = lrint(av_clipf(fabsf(src2[n]), 0, 1) * (w - 1));
 
                     shistogram[bin]++;
                 }
             }
         }
         break;
     case ALOG:
         for (c = 0; c < inlink->channels; c++) {
             const float *src = (const float *)in->extended_data[c];
             uint64_t *achistogram = &s->achistogram[(s->dmode == SINGLE ? 0: c) * w];
 
             for (n = 0; n < in->nb_samples; n++) {
                 bin = lrint(av_clipf(1 + log10(fabsf(src[n])) / 6, 0, 1) * (w - 1));
 
                 achistogram[bin]++;
             }
 
             if (s->in[s->first] && s->count >= 0) {
                 uint64_t *shistogram = &s->shistogram[(s->dmode == SINGLE ? 0: c) * w];
                 const float *src2 = (const float *)s->in[s->first]->extended_data[c];
 
                 for (n = 0; n < in->nb_samples; n++) {
                     bin = lrint(av_clipf(1 + log10(fabsf(src2[n])) / 6, 0, 1) * (w - 1));
 
                     shistogram[bin]++;
                 }
             }
         }
         break;
     }
 
     av_frame_free(&s->in[s->frame_count]);
     s->in[s->frame_count] = in;
     s->frame_count++;
     if (s->frame_count > s->count)
         s->frame_count = 0;
 
     for (n = 0; n < w * s->dchannels; n++) {
         acmax = FFMAX(s->achistogram[n] - s->shistogram[n], acmax);
     }
 
     for (c = 0; c < s->dchannels; c++) {
         uint64_t *shistogram  = &s->shistogram[c * w];
         uint64_t *achistogram = &s->achistogram[c * w];
         float yf, uf, vf;
 
         if (s->dmode == SEPARATE) {
             yf = 256.0f / s->dchannels;
             uf = yf * M_PI;
             vf = yf * M_PI;
             uf *= 0.5 * sin((2 * M_PI * c) / s->dchannels);
             vf *= 0.5 * cos((2 * M_PI * c) / s->dchannels);
         }
 
         for (n = 0; n < w; n++) {
             double a, aa;
             int h;
 
             a = achistogram[n] - shistogram[n];
 
             switch (s->scale) {
             case LINEAR:
                 aa = a / (double)acmax;
                 break;
             case SQRT:
                 aa = sqrt(a) / sqrt(acmax);
                 break;
             case CBRT:
                 aa = cbrt(a) / cbrt(acmax);
                 break;
             case LOG:
                 aa = log2(a + 1) / log2(acmax + 1);
                 break;
             case RLOG:
                 aa = 1. - log2(a + 1) / log2(acmax + 1);
                 if (aa == 1.)
                     aa = 0;
                 break;

             default:
                 av_assert0(0);

             }
 
             h = aa * (H - 1);
 
             if (s->dmode == SINGLE) {
 
                 for (y = H - h; y < H; y++) {
                     s->out->data[0][y * s->out->linesize[0] + n] = 255;
                     s->out->data[3][y * s->out->linesize[0] + n] = 255;
                 }
 
                 if (s->h - H > 0) {
                     h = aa * 255;
 
                     s->out->data[0][s->ypos * s->out->linesize[0] + n] = h;
                     s->out->data[1][s->ypos * s->out->linesize[1] + n] = 127;
                     s->out->data[2][s->ypos * s->out->linesize[2] + n] = 127;
                     s->out->data[3][s->ypos * s->out->linesize[3] + n] = 255;
                 }
             } else if (s->dmode == SEPARATE) {
                 float *out = &s->combine_buffer[3 * n];
                 int old;
 
                 old = s->out->data[0][(H - h) * s->out->linesize[0] + n];
                 for (y = H - h; y < H; y++) {
                     if (s->out->data[0][y * s->out->linesize[0] + n] != old)
                         break;
                     old = s->out->data[0][y * s->out->linesize[0] + n];
                     s->out->data[0][y * s->out->linesize[0] + n] = yf;
                     s->out->data[1][y * s->out->linesize[1] + n] = 128+uf;
                     s->out->data[2][y * s->out->linesize[2] + n] = 128+vf;
                     s->out->data[3][y * s->out->linesize[3] + n] = 255;
                 }
 
                 out[0] += aa * yf;
                 out[1] += aa * uf;
                 out[2] += aa * vf;
             }
         }
     }
 
     if (s->h - H > 0) {
         if (s->dmode == SEPARATE) {
             for (n = 0; n < w; n++) {
                 float *cb = &s->combine_buffer[3 * n];
 
                 s->out->data[0][s->ypos * s->out->linesize[0] + n] = cb[0];
                 s->out->data[1][s->ypos * s->out->linesize[1] + n] = cb[1];
                 s->out->data[2][s->ypos * s->out->linesize[2] + n] = cb[2];
                 s->out->data[3][s->ypos * s->out->linesize[3] + n] = 255;
             }
         }
 
         if (s->slide == SCROLL) {
             for (p = 0; p < 4; p++) {
                 for (y = s->h; y >= H + 1; y--) {
                     memmove(s->out->data[p] + (y  ) * s->out->linesize[p],
                             s->out->data[p] + (y-1) * s->out->linesize[p], w);
                 }
             }
         }
 
         s->ypos++;
         if (s->slide == SCROLL || s->ypos >= s->h)
             s->ypos = H;
     }
 
     return ff_filter_frame(outlink, av_frame_clone(s->out));
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     AudioHistogramContext *s = ctx->priv;
     int i;
 
     av_frame_free(&s->out);
     av_freep(&s->shistogram);
     av_freep(&s->achistogram);
     av_freep(&s->combine_buffer);
     for (i = 0; i < 101; i++)
         av_frame_free(&s->in[i]);
 }
 
 static const AVFilterPad audiovectorscope_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_AUDIO,
         .config_props = config_input,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad audiovectorscope_outputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_output,
     },
     { NULL }
 };
 
 AVFilter ff_avf_ahistogram = {
     .name          = "ahistogram",
     .description   = NULL_IF_CONFIG_SMALL("Convert input audio to histogram video output."),
     .uninit        = uninit,
     .query_formats = query_formats,
     .priv_size     = sizeof(AudioHistogramContext),
     .inputs        = audiovectorscope_inputs,
     .outputs       = audiovectorscope_outputs,
     .priv_class    = &ahistogram_class,
 };