/*
 * Original copyright (c) 2002 Remi Guyomarch <rguyom@pobox.com>
 * Port copyright (c) 2010 Daniel G. Taylor <dan@programmer-art.org>
 * Relicensed to the LGPL with permission from Remi Guyomarch.
 *
 * 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
 * blur / sharpen filter, ported to FFmpeg from MPlayer
 * libmpcodecs/unsharp.c.
 *
 * This code is based on:
 *
 * An Efficient algorithm for Gaussian blur using finite-state machines
 * Frederick M. Waltz and John W. V. Miller
 *
 * SPIE Conf. on Machine Vision Systems for Inspection and Metrology VII
 * Originally published Boston, Nov 98
 *
 * http://www.engin.umd.umich.edu/~jwvm/ece581/21_GBlur.pdf
 */

#include "avfilter.h"
#include "filters.h"
#include "video.h"
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"

#define MIN_MATRIX_SIZE 3
#define MAX_MATRIX_SIZE 63

typedef struct UnsharpFilterParam {
    int msize_x;                             ///< matrix width
    int msize_y;                             ///< matrix height
    int amount;                              ///< effect amount
    int steps_x;                             ///< horizontal step count
    int steps_y;                             ///< vertical step count
    int scalebits;                           ///< bits to shift pixel
    int32_t halfscale;                       ///< amount to add to pixel
    uint32_t *sr;        ///< finite state machine storage within a row
    uint32_t **sc;       ///< finite state machine storage across rows
} UnsharpFilterParam;

typedef struct UnsharpContext {
    const AVClass *class;
    int lmsize_x, lmsize_y, cmsize_x, cmsize_y;
    int amsize_x, amsize_y;
    float lamount, camount;
    float aamount;
    UnsharpFilterParam luma;   ///< luma parameters (width, height, amount)
    UnsharpFilterParam chroma; ///< chroma parameters (width, height, amount)
    UnsharpFilterParam alpha;  ///< alpha parameters (width, height, amount)
    int hsub, vsub;
    int nb_planes;
    int bitdepth;
    int bps;
    int nb_threads;
    int (* unsharp_slice)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
} UnsharpContext;

typedef struct TheadData {
    UnsharpFilterParam *fp;
    uint8_t       *dst;
    const uint8_t *src;
    int dst_stride;
    int src_stride;
    int width;
    int height;
} ThreadData;

#define DEF_UNSHARP_SLICE_FUNC(name, nbits)                                                           \
static int name##_##nbits(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)                    \
{                                                                                                     \
    ThreadData *td = arg;                                                                             \
    UnsharpFilterParam *fp = td->fp;                                                                  \
    UnsharpContext *s = ctx->priv;                                                                    \
    uint32_t **sc = fp->sc;                                                                           \
    uint32_t *sr = fp->sr;                                                                            \
    const uint##nbits##_t *src2 = NULL;                                                               \
    const int amount = fp->amount;                                                                    \
    const int steps_x = fp->steps_x;                                                                  \
    const int steps_y = fp->steps_y;                                                                  \
    const int scalebits = fp->scalebits;                                                              \
    const int32_t halfscale = fp->halfscale;                                                          \
                                                                                                      \
    uint##nbits##_t *dst = (uint##nbits##_t*)td->dst;                                                 \
    const uint##nbits##_t *src = (const uint##nbits##_t *)td->src;                                    \
    int dst_stride = td->dst_stride;                                                                  \
    int src_stride = td->src_stride;                                                                  \
    const int width = td->width;                                                                      \
    const int height = td->height;                                                                    \
    const int sc_offset = jobnr * 2 * steps_y;                                                        \
    const int sr_offset = jobnr * (MAX_MATRIX_SIZE - 1);                                              \
    const int slice_start = ff_slice_pos(height, jobnr, nb_jobs);                                     \
    const int slice_end = ff_slice_pos(height, jobnr + 1, nb_jobs);                                   \
                                                                                                      \
    int32_t res;                                                                                      \
    int x, y, z;                                                                                      \
    uint32_t tmp1, tmp2;                                                                              \
                                                                                                      \
    if (!amount) {                                                                                    \
        av_image_copy_plane(td->dst + slice_start * dst_stride, dst_stride,                           \
                            td->src + slice_start * src_stride, src_stride,                           \
                            width * s->bps, slice_end - slice_start);                                 \
        return 0;                                                                                     \
    }                                                                                                 \
                                                                                                      \
    for (y = 0; y < 2 * steps_y; y++)                                                                 \
        memset(sc[sc_offset + y], 0, sizeof(sc[y][0]) * (width + 2 * steps_x));                       \
                                                                                                      \
    dst_stride = dst_stride / s->bps;                                                                 \
    src_stride = src_stride / s->bps;                                                                 \
    /* if this is not the first tile, we start from (slice_start - steps_y) */                        \
    /* so we can get smooth result at slice boundary */                                               \
    if (slice_start > steps_y) {                                                                      \
        src += (slice_start - steps_y) * src_stride;                                                  \
        dst += (slice_start - steps_y) * dst_stride;                                                  \
    }                                                                                                 \
                                                                                                      \
    for (y = -steps_y + slice_start; y < steps_y + slice_end; y++) {                                  \
        if (y < height)                                                                               \
            src2 = src;                                                                               \
                                                                                                      \
        memset(sr + sr_offset, 0, sizeof(sr[0]) * (2 * steps_x - 1));                                 \
        for (x = -steps_x; x < width + steps_x; x++) {                                                \
            tmp1 = x <= 0 ? src2[0] : x >= width ? src2[width-1] : src2[x];                           \
            for (z = 0; z < steps_x * 2; z += 2) {                                                    \
                tmp2 = sr[sr_offset + z + 0] + tmp1; sr[sr_offset + z + 0] = tmp1;                    \
                tmp1 = sr[sr_offset + z + 1] + tmp2; sr[sr_offset + z + 1] = tmp2;                    \
            }                                                                                         \
            for (z = 0; z < steps_y * 2; z += 2) {                                                    \
                tmp2 = sc[sc_offset + z + 0][x + steps_x] + tmp1;                                     \
                sc[sc_offset + z + 0][x + steps_x] = tmp1;                                            \
                tmp1 = sc[sc_offset + z + 1][x + steps_x] + tmp2;                                     \
                sc[sc_offset + z + 1][x + steps_x] = tmp2;                                            \
            }                                                                                         \
            if (x >= steps_x && y >= (steps_y + slice_start)) {                                       \
                const uint##nbits##_t *srx = src - steps_y * src_stride + x - steps_x;                \
                uint##nbits##_t *dsx       = dst - steps_y * dst_stride + x - steps_x;                \
                                                                                                      \
                res = (int32_t)*srx + ((((int32_t) * srx -                                            \
                      (int32_t)((tmp1 + halfscale) >> scalebits)) * amount) >> (8+nbits));            \
                *dsx = av_clip_uint##nbits(res);                                                      \
            }                                                                                         \
        }                                                                                             \
        if (y >= 0) {                                                                                 \
            dst += dst_stride;                                                                        \
            src += src_stride;                                                                        \
        }                                                                                             \
    }                                                                                                 \
    return 0;                                                                                         \
}
DEF_UNSHARP_SLICE_FUNC(unsharp_slice, 16)
DEF_UNSHARP_SLICE_FUNC(unsharp_slice, 8)

static int apply_unsharp(AVFilterContext *ctx, AVFrame *in, AVFrame *out)
{
    AVFilterLink *inlink = ctx->inputs[0];
    UnsharpContext *s = ctx->priv;
    int i, plane_w[4], plane_h[4];
    UnsharpFilterParam *fp[4];
    ThreadData td;

    plane_w[0] = plane_w[3] = inlink->w;
    plane_w[1] = plane_w[2] = AV_CEIL_RSHIFT(inlink->w, s->hsub);
    plane_h[0] = plane_h[3] = inlink->h;
    plane_h[1] = plane_h[2] = AV_CEIL_RSHIFT(inlink->h, s->vsub);
    fp[0] = &s->luma;
    fp[1] = fp[2] = &s->chroma;
    fp[3] = &s->alpha;
    for (i = 0; i < s->nb_planes; i++) {
        td.fp = fp[i];
        td.dst = out->data[i];
        td.src = in->data[i];
        td.width = plane_w[i];
        td.height = plane_h[i];
        td.dst_stride = out->linesize[i];
        td.src_stride = in->linesize[i];
        ff_filter_execute(ctx, s->unsharp_slice, &td, NULL,
                          FFMIN(plane_h[i], s->nb_threads));
    }
    return 0;
}

#define MAX_SCALEBITS 25

static int set_filter_param(AVFilterContext *ctx, const char *name, const char *short_name,
                            UnsharpFilterParam *fp, int msize_x, int msize_y, float amount)
{
    fp->msize_x = msize_x;
    fp->msize_y = msize_y;
    fp->amount = amount * 65536.0;

    fp->steps_x = msize_x / 2;
    fp->steps_y = msize_y / 2;
    fp->scalebits = (fp->steps_x + fp->steps_y) * 2;
    fp->halfscale = 1 << (fp->scalebits - 1);

    if (fp->scalebits > MAX_SCALEBITS) {
        av_log(ctx, AV_LOG_ERROR, "%s matrix size (%sx/2+%sy/2)*2=%d greater than maximum value %d\n",
               name, short_name, short_name, fp->scalebits, MAX_SCALEBITS);
        return AVERROR(EINVAL);
    }

    return 0;
}

static av_cold int init(AVFilterContext *ctx)
{
    UnsharpContext *s = ctx->priv;
    int ret;

#define SET_FILTER_PARAM(name_, short_)                                 \
    ret = set_filter_param(ctx, #name_, #short_, &s->name_,             \
                           s->short_##msize_x, s->short_##msize_y, s->short_##amount); \
    if (ret < 0)                                                        \
        return ret;                                                     \

    SET_FILTER_PARAM(luma, l);
    SET_FILTER_PARAM(chroma, c);
    SET_FILTER_PARAM(alpha, a);

    return 0;
}

static const enum AVPixelFormat pix_fmts[] = {
    AV_PIX_FMT_YUVA420P,  AV_PIX_FMT_YUVA422P,   AV_PIX_FMT_YUVA444P,
    AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12, AV_PIX_FMT_YUVA444P16,
    AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA422P16,
    AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA420P16,
    AV_PIX_FMT_YUV420P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV410P,
    AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
    AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
    AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV440P10,
    AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV440P12,
    AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
    AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_NONE
};

static int init_filter_param(AVFilterContext *ctx, UnsharpFilterParam *fp, const char *effect_type, int width)
{
    int z;
    UnsharpContext *s = ctx->priv;
    const char *effect = fp->amount == 0 ? "none" : fp->amount < 0 ? "blur" : "sharpen";

    if  (!(fp->msize_x & fp->msize_y & 1)) {
        av_log(ctx, AV_LOG_ERROR,
               "Invalid even size for %s matrix size %dx%d\n",
               effect_type, fp->msize_x, fp->msize_y);
        return AVERROR(EINVAL);
    }

    av_log(ctx, AV_LOG_VERBOSE, "effect:%s type:%s msize_x:%d msize_y:%d amount:%0.2f\n",
           effect, effect_type, fp->msize_x, fp->msize_y, fp->amount / 65535.0);

    fp->sr = av_malloc_array((MAX_MATRIX_SIZE - 1) * s->nb_threads, sizeof(uint32_t));
    fp->sc = av_calloc(fp->steps_y * s->nb_threads, 2 * sizeof(*fp->sc));
    if (!fp->sr || !fp->sc)
        return AVERROR(ENOMEM);

    for (z = 0; z < 2 * fp->steps_y * s->nb_threads; z++)
        if (!(fp->sc[z] = av_malloc_array(width + 2 * fp->steps_x,
                                          sizeof(*(fp->sc[z])))))
            return AVERROR(ENOMEM);

    return 0;
}

static int config_input(AVFilterLink *inlink)
{
    UnsharpContext *s = inlink->dst->priv;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
    int ret;

    s->nb_planes = desc->nb_components;
    s->hsub = desc->log2_chroma_w;
    s->vsub = desc->log2_chroma_h;
    s->bitdepth = desc->comp[0].depth;
    s->bps = s->bitdepth > 8 ? 2 : 1;
    s->unsharp_slice = s->bitdepth > 8 ? unsharp_slice_16 : unsharp_slice_8;

    // ensure (height / nb_threads) > 4 * steps_y,
    // so that we don't have too much overlap between two threads
    s->nb_threads = FFMIN(ff_filter_get_nb_threads(inlink->dst),
                          inlink->h / (4 * s->luma.steps_y));

    ret = init_filter_param(inlink->dst, &s->luma,   "luma",   inlink->w);
    if (ret < 0)
        return ret;
    ret = init_filter_param(inlink->dst, &s->chroma, "chroma", AV_CEIL_RSHIFT(inlink->w, s->hsub));
    if (ret < 0)
        return ret;

    return 0;
}

static void free_filter_param(UnsharpFilterParam *fp, int nb_threads)
{
    int z;

    if (fp->sc) {
        for (z = 0; z < 2 * fp->steps_y * nb_threads; z++)
            av_freep(&fp->sc[z]);
        av_freep(&fp->sc);
    }
    av_freep(&fp->sr);
}

static av_cold void uninit(AVFilterContext *ctx)
{
    UnsharpContext *s = ctx->priv;

    free_filter_param(&s->luma, s->nb_threads);
    free_filter_param(&s->chroma, s->nb_threads);
}

static int filter_frame(AVFilterLink *link, AVFrame *in)
{
    AVFilterLink *outlink   = link->dst->outputs[0];
    AVFrame *out;
    int ret = 0;

    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
    if (!out) {
        av_frame_free(&in);
        return AVERROR(ENOMEM);
    }
    av_frame_copy_props(out, in);

    ret = apply_unsharp(link->dst, in, out);

    av_frame_free(&in);

    if (ret < 0) {
        av_frame_free(&out);
        return ret;
    }
    return ff_filter_frame(outlink, out);
}

#define OFFSET(x) offsetof(UnsharpContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define MIN_SIZE 3
#define MAX_SIZE 23
static const AVOption unsharp_options[] = {
    { "luma_msize_x",   "set luma matrix horizontal size",   OFFSET(lmsize_x), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "lx",             "set luma matrix horizontal size",   OFFSET(lmsize_x), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "luma_msize_y",   "set luma matrix vertical size",     OFFSET(lmsize_y), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "ly",             "set luma matrix vertical size",     OFFSET(lmsize_y), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "luma_amount",    "set luma effect strength",          OFFSET(lamount),  AV_OPT_TYPE_FLOAT, { .dbl = 1 },       -2,        5, FLAGS },
    { "la",             "set luma effect strength",          OFFSET(lamount),  AV_OPT_TYPE_FLOAT, { .dbl = 1 },       -2,        5, FLAGS },
    { "chroma_msize_x", "set chroma matrix horizontal size", OFFSET(cmsize_x), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "cx",             "set chroma matrix horizontal size", OFFSET(cmsize_x), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "chroma_msize_y", "set chroma matrix vertical size",   OFFSET(cmsize_y), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "cy",             "set chroma matrix vertical size",   OFFSET(cmsize_y), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "chroma_amount",  "set chroma effect strength",        OFFSET(camount),  AV_OPT_TYPE_FLOAT, { .dbl = 0 },       -2,        5, FLAGS },
    { "ca",             "set chroma effect strength",        OFFSET(camount),  AV_OPT_TYPE_FLOAT, { .dbl = 0 },       -2,        5, FLAGS },
    { "alpha_msize_x",  "set alpha matrix horizontal size",  OFFSET(amsize_x), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "ax",             "set alpha matrix horizontal size",  OFFSET(amsize_x), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "alpha_msize_y",  "set alpha matrix vertical size",    OFFSET(amsize_y), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "ay",             "set alpha matrix vertical size",    OFFSET(amsize_y), AV_OPT_TYPE_INT,   { .i64 = 5 }, MIN_SIZE, MAX_SIZE, FLAGS },
    { "alpha_amount",   "set alpha effect strength",         OFFSET(aamount),  AV_OPT_TYPE_FLOAT, { .dbl = 0 },       -2,        5, FLAGS },
    { "aa",             "set alpha effect strength",         OFFSET(aamount),  AV_OPT_TYPE_FLOAT, { .dbl = 0 },       -2,        5, FLAGS },
    { NULL }
};

AVFILTER_DEFINE_CLASS(unsharp);

static const AVFilterPad avfilter_vf_unsharp_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
        .config_props = config_input,
    },
};

const FFFilter ff_vf_unsharp = {
    .p.name        = "unsharp",
    .p.description = NULL_IF_CONFIG_SMALL("Sharpen or blur the input video."),
    .p.priv_class  = &unsharp_class,
    .p.flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
    .priv_size     = sizeof(UnsharpContext),
    .init          = init,
    .uninit        = uninit,
    FILTER_INPUTS(avfilter_vf_unsharp_inputs),
    FILTER_OUTPUTS(ff_video_default_filterpad),
    FILTER_PIXFMTS_ARRAY(pix_fmts),
};
