/*
 * Copyright (c) 2013 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
 */

/**
 * @file
 * audio to video multimedia vectorscope filter
 */

#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "avfilter.h"
#include "filters.h"
#include "formats.h"
#include "audio.h"
#include "video.h"
#include "internal.h"

enum VectorScopeMode {
    LISSAJOUS,
    LISSAJOUS_XY,
    POLAR,
    MODE_NB,
};

enum VectorScopeDraw {
    DOT,
    LINE,
    AALINE,
    DRAW_NB,
};

enum VectorScopeScale {
    LIN,
    SQRT,
    CBRT,
    LOG,
    SCALE_NB,
};

typedef struct AudioVectorScopeContext {
    const AVClass *class;
    AVFrame *outpicref;
    int w, h;
    int hw, hh;
    int mode;
    int draw;
    int scale;
    int contrast[4];
    int fade[4];
    double zoom;
    int swap;
    int mirror;
    unsigned prev_x, prev_y;
    AVRational frame_rate;
    int nb_samples;
} AudioVectorScopeContext;

#define OFFSET(x) offsetof(AudioVectorScopeContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define TFLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM

static const AVOption avectorscope_options[] = {
    { "mode", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=LISSAJOUS}, 0, MODE_NB-1, TFLAGS, .unit = "mode" },
    { "m",    "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=LISSAJOUS}, 0, MODE_NB-1, TFLAGS, .unit = "mode" },
    { "lissajous",    "", 0, AV_OPT_TYPE_CONST, {.i64=LISSAJOUS},    0, 0, TFLAGS, .unit = "mode" },
    { "lissajous_xy", "", 0, AV_OPT_TYPE_CONST, {.i64=LISSAJOUS_XY}, 0, 0, TFLAGS, .unit = "mode" },
    { "polar",        "", 0, AV_OPT_TYPE_CONST, {.i64=POLAR},        0, 0, TFLAGS, .unit = "mode" },
    { "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="400x400"}, 0, 0, FLAGS },
    { "s",    "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="400x400"}, 0, 0, FLAGS },
    { "rc", "set red contrast",   OFFSET(contrast[0]), AV_OPT_TYPE_INT, {.i64=40},  0, 255, TFLAGS },
    { "gc", "set green contrast", OFFSET(contrast[1]), AV_OPT_TYPE_INT, {.i64=160}, 0, 255, TFLAGS },
    { "bc", "set blue contrast",  OFFSET(contrast[2]), AV_OPT_TYPE_INT, {.i64=80},  0, 255, TFLAGS },
    { "ac", "set alpha contrast", OFFSET(contrast[3]), AV_OPT_TYPE_INT, {.i64=255}, 0, 255, TFLAGS },
    { "rf", "set red fade",       OFFSET(fade[0]), AV_OPT_TYPE_INT, {.i64=15}, 0, 255, TFLAGS },
    { "gf", "set green fade",     OFFSET(fade[1]), AV_OPT_TYPE_INT, {.i64=10}, 0, 255, TFLAGS },
    { "bf", "set blue fade",      OFFSET(fade[2]), AV_OPT_TYPE_INT, {.i64=5},  0, 255, TFLAGS },
    { "af", "set alpha fade",     OFFSET(fade[3]), AV_OPT_TYPE_INT, {.i64=5},  0, 255, TFLAGS },
    { "zoom", "set zoom factor",  OFFSET(zoom), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 10, TFLAGS },
    { "draw", "set draw mode", OFFSET(draw), AV_OPT_TYPE_INT, {.i64=DOT}, 0, DRAW_NB-1, TFLAGS, .unit = "draw" },
    { "dot",   "draw dots",               0, AV_OPT_TYPE_CONST, {.i64=DOT} , 0, 0, TFLAGS, .unit = "draw" },
    { "line",  "draw lines",              0, AV_OPT_TYPE_CONST, {.i64=LINE}, 0, 0, TFLAGS, .unit = "draw" },
    { "aaline","draw anti-aliased lines", 0, AV_OPT_TYPE_CONST, {.i64=AALINE},0,0, TFLAGS, .unit = "draw" },
    { "scale", "set amplitude scale mode", OFFSET(scale), AV_OPT_TYPE_INT, {.i64=LIN}, 0, SCALE_NB-1, TFLAGS, .unit = "scale" },
    { "lin",   "linear",      0, AV_OPT_TYPE_CONST, {.i64=LIN},  0, 0, TFLAGS, .unit = "scale" },
    { "sqrt",  "square root", 0, AV_OPT_TYPE_CONST, {.i64=SQRT}, 0, 0, TFLAGS, .unit = "scale" },
    { "cbrt",  "cube root",   0, AV_OPT_TYPE_CONST, {.i64=CBRT}, 0, 0, TFLAGS, .unit = "scale" },
    { "log",   "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=LOG},  0, 0, TFLAGS, .unit = "scale" },
    { "swap", "swap x axis with y axis", OFFSET(swap), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, TFLAGS },
    { "mirror", "mirror axis", OFFSET(mirror), AV_OPT_TYPE_INT, {.i64=0}, 0, 3, TFLAGS, .unit = "mirror" },
    { "none",  "no mirror", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, TFLAGS, .unit = "mirror" },
    { "x",  "mirror x",     0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, TFLAGS, .unit = "mirror" },
    { "y",  "mirror y",     0, AV_OPT_TYPE_CONST, {.i64=2}, 0, 0, TFLAGS, .unit = "mirror" },
    { "xy", "mirror both",  0, AV_OPT_TYPE_CONST, {.i64=3}, 0, 0, TFLAGS, .unit = "mirror" },
    { NULL }
};

AVFILTER_DEFINE_CLASS(avectorscope);

static void draw_dot(AudioVectorScopeContext *s, unsigned x, unsigned y, int value)
{
    const ptrdiff_t linesize = s->outpicref->linesize[0];
    uint8_t *dst;

    if (s->zoom > 1) {
        if (y >= s->h || x >= s->w)
            return;
    } else {
        y = FFMIN(y, s->h - 1);
        x = FFMIN(x, s->w - 1);
    }

    dst = s->outpicref->data[0] + y * linesize + x * 4;
    dst[0] = FFMIN(dst[0] + s->contrast[0], value);
    dst[1] = FFMIN(dst[1] + s->contrast[1], value);
    dst[2] = FFMIN(dst[2] + s->contrast[2], value);
    dst[3] = FFMIN(dst[3] + s->contrast[3], value);
}

static void draw_line(AudioVectorScopeContext *s, int x0, int y0, int x1, int y1)
{
    int dx = FFABS(x1-x0), sx = x0 < x1 ? 1 : -1;
    int dy = FFABS(y1-y0), sy = y0 < y1 ? 1 : -1;
    int err = (dx>dy ? dx : -dy) / 2, e2;

    for (;;) {
        draw_dot(s, x0, y0, 255);

        if (x0 == x1 && y0 == y1)
            break;

        e2 = err;

        if (e2 >-dx) {
            err -= dy;
            x0 += sx;
        }

        if (e2 < dy) {
            err += dx;
            y0 += sy;
        }
    }
}

static void draw_aaline(AudioVectorScopeContext *s, int x0, int y0, int x1, int y1)
{
    int sx = x0 < x1 ? 1 : -1, sy = y0 < y1 ? 1 : -1, x2;
    int dx = FFABS(x1-x0), dy = FFABS(y1-y0), err = dx * dx + dy * dy;
    int e2 = err == 0 ? 1 : 0xffffff / (dx + dy);

    dx *= e2;
    dy *= e2;
    err = dx - dy;

    for (;;) {
        draw_dot(s, x0, y0, 255-(FFABS(err - dx + dy) >> 16));
        e2 = err;
        x2 = x0;
        if (2 * e2 >= -dx) {
            if (x0 == x1)
                break;
            if (e2 + dy < 0xff0000)
                draw_dot(s, x0, y0 + sy, 255-((e2 + dy) >> 16));
            err -= dy;
            x0 += sx;
        }

        if (2 * e2 <= dy) {
            if (y0 == y1)
                break;
            if (dx - e2 < 0xff0000)
                draw_dot(s, x2 + sx, y0, 255-((dx - e2) >> 16));
            err += dx;
            y0 += sy;
        }
    }
}

static int fade(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
{
    AudioVectorScopeContext *s = ctx->priv;
    const int linesize = s->outpicref->linesize[0];
    const int height = s->outpicref->height;
    const int slice_start = (height *  jobnr   ) / nb_jobs;
    const int slice_end   = (height * (jobnr+1)) / nb_jobs;

    if (s->fade[0] == 255 && s->fade[1] == 255 && s->fade[2] == 255) {
        for (int i = slice_start; i < slice_end; i++)
            memset(s->outpicref->data[0] + i * linesize, 0, s->outpicref->width * 4);
        return 0;
    }

    if (s->fade[0] || s->fade[1] || s->fade[2]) {
        uint8_t *d = s->outpicref->data[0] + slice_start * linesize;
        for (int i = slice_start; i < slice_end; i++) {
            for (int j = 0; j < s->w*4; j+=4) {
                if (d[j+0])
                    d[j+0] = FFMAX(d[j+0] - s->fade[0], 0);
                if (d[j+1])
                    d[j+1] = FFMAX(d[j+1] - s->fade[1], 0);
                if (d[j+2])
                    d[j+2] = FFMAX(d[j+2] - s->fade[2], 0);
                if (d[j+3])
                    d[j+3] = FFMAX(d[j+3] - s->fade[3], 0);
            }
            d += linesize;
        }
    }

    return 0;
}

static int query_formats(AVFilterContext *ctx)
{
    AVFilterFormats *formats = NULL;
    AVFilterChannelLayouts *layout = NULL;
    AVFilterLink *inlink = ctx->inputs[0];
    AVFilterLink *outlink = ctx->outputs[0];
    static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_NONE };
    static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };
    int ret;

    formats = ff_make_format_list(sample_fmts);
    if ((ret = ff_formats_ref         (formats, &inlink->outcfg.formats        )) < 0 ||
        (ret = ff_add_channel_layout  (&layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO)) < 0 ||
        (ret = ff_channel_layouts_ref (layout , &inlink->outcfg.channel_layouts)) < 0)
        return ret;

    formats = ff_all_samplerates();
    if ((ret = ff_formats_ref(formats, &inlink->outcfg.samplerates)) < 0)
        return ret;

    formats = ff_make_format_list(pix_fmts);
    if ((ret = ff_formats_ref(formats, &outlink->incfg.formats)) < 0)
        return ret;

    return 0;
}

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

    s->nb_samples = FFMAX(1, av_rescale(inlink->sample_rate, s->frame_rate.den, s->frame_rate.num));

    return 0;
}

static int config_output(AVFilterLink *outlink)
{
    AudioVectorScopeContext *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;
    outlink->time_base = av_inv_q(outlink->frame_rate);

    s->prev_x = s->hw = s->w / 2;
    s->prev_y = s->hh = s->mode == POLAR ? s->h - 1 : s->h / 2;

    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
{
    AVFilterContext *ctx = inlink->dst;
    AVFilterLink *outlink = ctx->outputs[0];
    const int16_t *samples = (const int16_t *)insamples->data[0];
    const float *samplesf = (const float *)insamples->data[0];
    AudioVectorScopeContext *s = ctx->priv;
    const int hw = s->hw;
    const int hh = s->hh;
    AVFrame *clone;
    unsigned x, y;
    unsigned prev_x = s->prev_x, prev_y = s->prev_y;
    double zoom = s->zoom;
    int ret;

    if (!s->outpicref || s->outpicref->width  != outlink->w ||
                         s->outpicref->height != outlink->h) {
        av_frame_free(&s->outpicref);
        s->outpicref = ff_get_video_buffer(outlink, outlink->w, outlink->h);
        if (!s->outpicref) {
            av_frame_free(&insamples);
            return AVERROR(ENOMEM);
        }

        s->outpicref->sample_aspect_ratio = (AVRational){1,1};
        for (int i = 0; i < outlink->h; i++)
            memset(s->outpicref->data[0] + i * s->outpicref->linesize[0], 0, outlink->w * 4);
    }
    s->outpicref->pts = av_rescale_q(insamples->pts, inlink->time_base, outlink->time_base);
    s->outpicref->duration = 1;

    ret = ff_inlink_make_frame_writable(outlink, &s->outpicref);
    if (ret < 0) {
        av_frame_free(&insamples);
        return ret;
    }
    ff_filter_execute(ctx, fade, NULL, NULL, FFMIN(outlink->h, ff_filter_get_nb_threads(ctx)));

    if (zoom < 1) {
        float max = 0;

        switch (insamples->format) {
        case AV_SAMPLE_FMT_S16:
            for (int i = 0; i < insamples->nb_samples * 2; i++) {
                float sample = samples[i] / (float)INT16_MAX;
                max = FFMAX(FFABS(sample), max);
            }
            break;
        case AV_SAMPLE_FMT_FLT:
            for (int i = 0; i < insamples->nb_samples * 2; i++) {
                max = FFMAX(FFABS(samplesf[i]), max);
            }
            break;
        default:
            av_assert2(0);
        }

        switch (s->scale) {
        case SQRT:
            max = sqrtf(max);
            break;
        case CBRT:
            max = cbrtf(max);
            break;
        case LOG:
            max = logf(1 + max) / logf(2);
            break;
        }

        if (max > 0.f)
            zoom = 1. / max;
    }

    for (int i = 0; i < insamples->nb_samples; i++) {
        float src[2];

        switch (insamples->format) {
        case AV_SAMPLE_FMT_S16:
            src[0] = samples[i*2+0] / (float)INT16_MAX;
            src[1] = samples[i*2+1] / (float)INT16_MAX;
            break;
        case AV_SAMPLE_FMT_FLT:
            src[0] = samplesf[i*2+0];
            src[1] = samplesf[i*2+1];
            break;
        default:
            av_assert2(0);
        }

        switch (s->scale) {
        case SQRT:
            src[0] = FFSIGN(src[0]) * sqrtf(FFABS(src[0]));
            src[1] = FFSIGN(src[1]) * sqrtf(FFABS(src[1]));
            break;
        case CBRT:
            src[0] = FFSIGN(src[0]) * cbrtf(FFABS(src[0]));
            src[1] = FFSIGN(src[1]) * cbrtf(FFABS(src[1]));
            break;
        case LOG:
            src[0] = FFSIGN(src[0]) * logf(1 + FFABS(src[0])) / logf(2);
            src[1] = FFSIGN(src[1]) * logf(1 + FFABS(src[1])) / logf(2);
            break;
        }

        if (s->mirror & 1)
            src[0] = -src[0];

        if (s->mirror & 2)
            src[1] = -src[1];

        if (s->swap)
            FFSWAP(float, src[0], src[1]);

        if (s->mode == LISSAJOUS) {
            x = ((src[1] - src[0]) * zoom / 2 + 1) * hw;
            y = (1.0 - (src[0] + src[1]) * zoom / 2) * hh;
        } else if (s->mode == LISSAJOUS_XY) {
            x = (src[1] * zoom + 1) * hw;
            y = (src[0] * zoom + 1) * hh;
        } else {
            float sx, sy, cx, cy;

            sx = src[1] * zoom;
            sy = src[0] * zoom;
            cx = sx * sqrtf(1 - 0.5 * sy * sy);
            cy = sy * sqrtf(1 - 0.5 * sx * sx);
            x = hw + hw * FFSIGN(cx + cy) * (cx - cy) * .7;
            y = s->h - s->h * fabsf(cx + cy) * .7;
        }

        if (s->draw == DOT) {
            draw_dot(s, x, y, 255);
        } else if (s->draw == LINE) {
            draw_line(s, x, y, prev_x, prev_y);
        } else {
            draw_aaline(s, x, y, prev_x, prev_y);
        }
        prev_x = x;
        prev_y = y;
    }

    s->prev_x = x, s->prev_y = y;
    av_frame_free(&insamples);

    clone = av_frame_clone(s->outpicref);
    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];
    AudioVectorScopeContext *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)
{
    AudioVectorScopeContext *s = ctx->priv;

    av_frame_free(&s->outpicref);
}

static const AVFilterPad audiovectorscope_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_AUDIO,
        .config_props = config_input,
    },
};

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

const AVFilter ff_avf_avectorscope = {
    .name          = "avectorscope",
    .description   = NULL_IF_CONFIG_SMALL("Convert input audio to vectorscope video output."),
    .uninit        = uninit,
    .priv_size     = sizeof(AudioVectorScopeContext),
    .activate      = activate,
    FILTER_INPUTS(audiovectorscope_inputs),
    FILTER_OUTPUTS(audiovectorscope_outputs),
    FILTER_QUERY_FUNC(query_formats),
    .priv_class    = &avectorscope_class,
    .flags         = AVFILTER_FLAG_SLICE_THREADS,
    .process_command = ff_filter_process_command,
};