/*
 * 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/mem.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "filters.h"
#include "formats.h"
#include "video.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  { ABS, SIGN, 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 hmode;
    int dchannels;
    int count;
    int frame_count;
    float *combine_buffer;
    AVFrame *in[101];
    int first;
    int nb_samples;

    int (*get_bin)(float in, int w);
} 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, .unit = "dmode" },
        { "single", "all channels use single histogram", 0, AV_OPT_TYPE_CONST, {.i64=SINGLE},   0, 0, FLAGS, .unit = "dmode" },
        { "separate", "each channel have own histogram", 0, AV_OPT_TYPE_CONST, {.i64=SEPARATE}, 0, 0, FLAGS, .unit = "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, .unit = "scale" },
        { "log",  "logarithmic",         0, AV_OPT_TYPE_CONST, {.i64=LOG},    0, 0, FLAGS, .unit = "scale" },
        { "sqrt", "square root",         0, AV_OPT_TYPE_CONST, {.i64=SQRT},   0, 0, FLAGS, .unit = "scale" },
        { "cbrt", "cubic root",          0, AV_OPT_TYPE_CONST, {.i64=CBRT},   0, 0, FLAGS, .unit = "scale" },
        { "lin",  "linear",              0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, .unit = "scale" },
        { "rlog", "reverse logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=RLOG},   0, 0, FLAGS, .unit = "scale" },
    { "ascale", "set amplitude scale", OFFSET(ascale), AV_OPT_TYPE_INT, {.i64=ALOG}, LINEAR, NB_ASCALES-1, FLAGS, .unit = "ascale" },
        { "log",  "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=ALOG},    0, 0, FLAGS, .unit = "ascale" },
        { "lin",  "linear",      0, AV_OPT_TYPE_CONST, {.i64=ALINEAR}, 0, 0, FLAGS, .unit = "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, .unit = "slide" },
        { "replace", "replace old rows with new", 0, AV_OPT_TYPE_CONST, {.i64=REPLACE},    0, 0, FLAGS, .unit = "slide" },
        { "scroll",  "scroll from top to bottom", 0, AV_OPT_TYPE_CONST, {.i64=SCROLL}, 0, 0, FLAGS, .unit = "slide" },
    { "hmode", "set histograms mode", OFFSET(hmode), AV_OPT_TYPE_INT, {.i64=ABS}, 0, NB_HMODES-1, FLAGS, .unit = "hmode" },
        { "abs",  "use absolute samples",  0, AV_OPT_TYPE_CONST, {.i64=ABS}, 0, 0, FLAGS, .unit = "hmode" },
        { "sign", "use unchanged samples", 0, AV_OPT_TYPE_CONST, {.i64=SIGN},0, 0, FLAGS, .unit = "hmode" },
    { NULL }
};

AVFILTER_DEFINE_CLASS(ahistogram);

static int query_formats(const AVFilterContext *ctx,
                         AVFilterFormatsConfig **cfg_in,
                         AVFilterFormatsConfig **cfg_out)
{
    AVFilterFormats *formats = NULL;
    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, &cfg_in[0]->formats)) < 0)
        return ret;

    formats = ff_make_format_list(pix_fmts);
    if ((ret = ff_formats_ref(formats, &cfg_out[0]->formats)) < 0)
        return ret;

    return 0;
}

static int config_input(AVFilterLink *inlink)
{
    AVFilterContext *ctx = inlink->dst;
    AudioHistogramContext *s = ctx->priv;

    s->nb_samples = FFMAX(1, av_rescale(inlink->sample_rate, s->frame_rate.den, s->frame_rate.num));
    s->dchannels = s->dmode == SINGLE ? 1 : inlink->ch_layout.nb_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 get_lin_bin_abs(float in, int w)
{
    return lrintf(av_clipf(fabsf(in), 0.f, 1.f) * (w - 1));
}

static int get_lin_bin_sign(float in, int w)
{
    return lrintf((1.f + av_clipf(in, -1.f, 1.f)) * 0.5f * (w - 1));
}

static int get_log_bin_abs(float in, int w)
{
    return lrintf(av_clipf(1.f + log10f(fabsf(in)) / 6.f, 0.f, 1.f) * (w - 1));
}

static int get_log_bin_sign(float in, int w)
{
    return (w / 2) + FFSIGN(in) * lrintf(av_clipf(1.f + log10f(fabsf(in)) / 6.f, 0.f, 1.f) * (w / 2));
}

static int config_output(AVFilterLink *outlink)
{
    AudioHistogramContext *s = outlink->src->priv;
    FilterLink *l = ff_filter_link(outlink);

    outlink->w = s->w;
    outlink->h = s->h;
    outlink->sample_aspect_ratio = (AVRational){1,1};
    l->frame_rate = s->frame_rate;
    outlink->time_base = av_inv_q(l->frame_rate);

    s->histogram_h = s->h * s->phisto;
    s->ypos = s->h * s->phisto;

    switch (s->ascale) {
    case ALINEAR:
        switch (s->hmode) {
        case ABS:  s->get_bin = get_lin_bin_abs;  break;
        case SIGN: s->get_bin = get_lin_bin_sign; break;
        default:
            return AVERROR_BUG;
        }
        break;
    case ALOG:
        switch (s->hmode) {
        case ABS:  s->get_bin = get_log_bin_abs;  break;
        case SIGN: s->get_bin = get_log_bin_sign; break;
        default:
            return AVERROR_BUG;
        }
        break;
    default:
        return AVERROR_BUG;
    }

    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 nb_samples = in->nb_samples;
    const int H = s->histogram_h;
    const int w = s->w;
    int c, y, n, p, bin, ret;
    uint64_t acmax = 1;
    AVFrame *clone;

    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);
        }
    }

    ret = ff_inlink_make_frame_writable(outlink, &s->out);
    if (ret < 0) {
        av_frame_free(&in);
        return ret;
    }

    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 = av_rescale_q(in->pts, inlink->time_base, outlink->time_base);
    s->out->duration = 1;

    s->first = s->frame_count;

    switch (s->ascale) {
    case ALINEAR:
        for (c = 0; c < inlink->ch_layout.nb_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 < nb_samples; n++) {
                bin = s->get_bin(src[n], w);

                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 < nb_samples; n++) {
                    bin = s->get_bin(src2[n], w);

                    shistogram[bin]++;
                }
            }
        }
        break;
    case ALOG:
        for (c = 0; c < inlink->ch_layout.nb_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 < nb_samples; n++) {
                bin = s->get_bin(src[n], w);

                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 < nb_samples; n++) {
                    bin = s->get_bin(src2[n], w);

                    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 = 255.0f / 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) {
                int start = H - h, end = H;
                const int linesizey = s->out->linesize[0];
                const int linesizea = s->out->linesize[3];
                uint8_t *dsty = s->out->data[0] + start * linesizey;
                uint8_t *dsta = s->out->data[3] + start * linesizea;

                for (y = start; y < end; y++, dsty += linesizey, dsta += linesizea) {
                    dsty[n] = 255;
                    dsta[n] = 255;
                }

                if (s->h - H > 0) {
                    h = aa * 255;

                    s->out->data[0][s->ypos * s->out->linesize[0] + n] = av_clip_uint8(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) {
                int start = H - h, end = H;
                float *out = &s->combine_buffer[3 * n];
                const int linesizey = s->out->linesize[0];
                const int linesizeu = s->out->linesize[1];
                const int linesizev = s->out->linesize[2];
                const int linesizea = s->out->linesize[3];
                uint8_t *dsty = s->out->data[0] + start * linesizey;
                uint8_t *dstu = s->out->data[1] + start * linesizeu;
                uint8_t *dstv = s->out->data[2] + start * linesizev;
                uint8_t *dsta = s->out->data[3] + start * linesizea;
                int old;

                old = dsty[n];
                for (y = start; y < end; y++) {
                    if (dsty[n] != old)
                        break;
                    old = dsty[n];
                    dsty[n] = av_clip_uint8(yf);
                    dstu[n] = av_clip_uint8(128.f+uf);
                    dstv[n] = av_clip_uint8(128.f+vf);
                    dsta[n] = 255;

                    dsty += linesizey;
                    dstu += linesizeu;
                    dstv += linesizev;
                    dsta += linesizea;
                }

                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 - 1; 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;
    }

    clone = av_frame_clone(s->out);
    if (!clone)
        return AVERROR(ENOMEM);

    return ff_filter_frame(outlink, clone);
}

static int activate(AVFilterContext *ctx)
{
    AVFilterLink *inlink = ctx->inputs[0];
    AVFilterLink *outlink = ctx->outputs[0];
    AudioHistogramContext *s = ctx->priv;
    AVFrame *in;
    int ret;

    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);

    ret = ff_inlink_consume_samples(inlink, s->nb_samples, s->nb_samples, &in);
    if (ret < 0)
        return ret;
    if (ret > 0)
        return filter_frame(inlink, in);

    if (ff_inlink_queued_samples(inlink) >= s->nb_samples) {
        ff_filter_set_ready(ctx, 10);
        return 0;
    }

    FF_FILTER_FORWARD_STATUS(inlink, outlink);
    FF_FILTER_FORWARD_WANTED(outlink, inlink);

    return FFERROR_NOT_READY;
}

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 ahistogram_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_AUDIO,
        .config_props = config_input,
    },
};

static const AVFilterPad ahistogram_outputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .config_props = config_output,
    },
};

const AVFilter ff_avf_ahistogram = {
    .name          = "ahistogram",
    .description   = NULL_IF_CONFIG_SMALL("Convert input audio to histogram video output."),
    .uninit        = uninit,
    .priv_size     = sizeof(AudioHistogramContext),
    .activate      = activate,
    FILTER_INPUTS(ahistogram_inputs),
    FILTER_OUTPUTS(ahistogram_outputs),
    FILTER_QUERY_FUNC2(query_formats),
    .priv_class    = &ahistogram_class,
};
