vf_fftfilt.c

/*
 * Copyright (c) 2015 Arwa Arif <arwaarif1994@gmail.com>
 *
 * 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
 * FFT domain filtering.
 */

#include "libavfilter/internal.h"
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavcodec/avfft.h"
#include "libavutil/eval.h"

#include "framesync2.h"

#define MAX_PLANES 4

typedef struct FFTFILTContext {
    const AVClass *class;
    FFFrameSync fs;

    RDFTContext *rdft;
    int rdft_hbits[MAX_PLANES];
    int rdft_vbits[MAX_PLANES];
    size_t rdft_hlen[MAX_PLANES];
    size_t rdft_vlen[MAX_PLANES];
    FFTSample *rdft_hdata[MAX_PLANES];
    FFTSample *rdft_vdata[MAX_PLANES];
    FFTSample *rdft_hdata_impulse[MAX_PLANES];
    FFTSample *rdft_vdata_impulse[MAX_PLANES];

    int dc[MAX_PLANES];
    char *weight_str[MAX_PLANES];
    AVExpr *weight_expr[MAX_PLANES];
    double *weight[MAX_PLANES];

    int planes;
} FFTFILTContext;

static const char *const var_names[] = {   "X",   "Y",   "W",   "H",     NULL    };
enum                                   { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_VARS_NB };

enum { Y = 0, U, V };

#define OFFSET(x) offsetof(FFTFILTContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

static const AVOption fftfilt_options[] = {
    { "dc_Y",  "adjust gain in Y plane",              OFFSET(dc[Y]),      AV_OPT_TYPE_INT,    {.i64 = 0},      0,     1000,     FLAGS },
    { "dc_U",  "adjust gain in U plane",              OFFSET(dc[U]),      AV_OPT_TYPE_INT,    {.i64 = 0},      0,     1000,     FLAGS },
    { "dc_V",  "adjust gain in V plane",              OFFSET(dc[V]),      AV_OPT_TYPE_INT,    {.i64 = 0},      0,     1000,     FLAGS },
    { "weight_Y", "set luminance expression in Y plane",   OFFSET(weight_str[Y]), AV_OPT_TYPE_STRING, {.str = "1"}, CHAR_MIN, CHAR_MAX, FLAGS },
    { "weight_U", "set chrominance expression in U plane", OFFSET(weight_str[U]), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
    { "weight_V", "set chrominance expression in V plane", OFFSET(weight_str[V]), AV_OPT_TYPE_STRING, {.str = NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
    {NULL},
};

AVFILTER_DEFINE_CLASS(fftfilt);

static inline double lum(void *priv, double x, double y, int plane)
{
    FFTFILTContext *s = priv;
    return s->rdft_vdata[plane][(int)x * s->rdft_vlen[plane] + (int)y];
}

static double weight_Y(void *priv, double x, double y) { return lum(priv, x, y, Y); }
static double weight_U(void *priv, double x, double y) { return lum(priv, x, y, U); }
static double weight_V(void *priv, double x, double y) { return lum(priv, x, y, V); }

static void copy_rev(FFTSample *dest, int w, int w2, float scale)
{
    int i;

    for (i = w; i < w + (w2-w)/2; i++)
        dest[i] = dest[2*w - i - 1] * scale;

    for (; i < w2; i++)
        dest[i] = dest[w2 - i] * scale;
}

/*Horizontal pass - RDFT*/
static void rdft_horizontal(FFTFILTContext *s, FFTSample *rdft_hdata, size_t rdft_hlen,
                            AVFrame *in, int w, int h, int plane, float scale)
{
    int i, j;
    s->rdft = av_rdft_init(s->rdft_hbits[plane], DFT_R2C);

    for (i = 0; i < h; i++) {
        for (j = 0; j < w; j++)
            rdft_hdata[i * rdft_hlen + j] = *(in->data[plane] + in->linesize[plane] * i + j) * scale;

        copy_rev(rdft_hdata + i * rdft_hlen, w, rdft_hlen, scale);
    }

    for (i = 0; i < h; i++)
        av_rdft_calc(s->rdft, rdft_hdata + i * rdft_hlen);

    av_rdft_end(s->rdft);
}

/*Vertical pass - RDFT*/
static void rdft_vertical(FFTFILTContext *s, FFTSample *rdft_hdata, FFTSample *rdft_vdata,
                          size_t rdft_hlen, size_t rdft_vlen,
                          int h, int plane)
{
    int i, j;
    s->rdft = av_rdft_init(s->rdft_vbits[plane], DFT_R2C);

    for (i = 0; i < rdft_hlen; i++) {
        for (j = 0; j < h; j++)
            rdft_vdata[i * rdft_vlen + j] = rdft_hdata[j * rdft_hlen + i];
        copy_rev(rdft_vdata + i * rdft_vlen, h, rdft_vlen, 1.f);
    }

    for (i = 0; i < rdft_hlen; i++)
        av_rdft_calc(s->rdft, rdft_vdata + i * rdft_vlen);

    av_rdft_end(s->rdft);
}

/*Vertical pass - IRDFT*/
static void irdft_vertical(FFTFILTContext *s, int h, int plane)
{
    int i, j;
    s->rdft = av_rdft_init(s->rdft_vbits[plane], IDFT_C2R);
    for (i = 0; i < s->rdft_hlen[plane]; i++)
        av_rdft_calc(s->rdft, s->rdft_vdata[plane] + i * s->rdft_vlen[plane]);

    for (i = 0; i < s->rdft_hlen[plane]; i++)
        for (j = 0; j < h; j++)
            s->rdft_hdata[plane][j * s->rdft_hlen[plane] + i] =
            s->rdft_vdata[plane][i * s->rdft_vlen[plane] + j];

    av_rdft_end(s->rdft);
}

/*Horizontal pass - IRDFT*/
static void irdft_horizontal(FFTFILTContext *s, AVFrame *out, int w, int h, int plane)
{
    int i, j;
    s->rdft = av_rdft_init(s->rdft_hbits[plane], IDFT_C2R);
    for (i = 0; i < h; i++)
        av_rdft_calc(s->rdft, s->rdft_hdata[plane] + i * s->rdft_hlen[plane]);

    for (i = 0; i < h; i++)
        for (j = 0; j < w; j++)
            *(out->data[plane] + out->linesize[plane] * i + j) = av_clip(s->rdft_hdata[plane][i
                                                                         *s->rdft_hlen[plane] + j] * 4 /
                                                                         (s->rdft_hlen[plane] *
                                                                          s->rdft_vlen[plane]), 0, 255);

    av_rdft_end(s->rdft);
}

static av_cold int initialize(AVFilterContext *ctx)
{
    FFTFILTContext *s = ctx->priv;
    int ret = 0, plane;

    if (!s->dc[U] && !s->dc[V]) {
        s->dc[U] = s->dc[Y];
        s->dc[V] = s->dc[Y];
    } else {
        if (!s->dc[U]) s->dc[U] = s->dc[V];
        if (!s->dc[V]) s->dc[V] = s->dc[U];
    }

    if (!s->weight_str[U] && !s->weight_str[V]) {
        s->weight_str[U] = av_strdup(s->weight_str[Y]);
        s->weight_str[V] = av_strdup(s->weight_str[Y]);
    } else {
        if (!s->weight_str[U]) s->weight_str[U] = av_strdup(s->weight_str[V]);
        if (!s->weight_str[V]) s->weight_str[V] = av_strdup(s->weight_str[U]);
    }

    for (plane = 0; plane < 3; plane++) {
        static double (*p[])(void *, double, double) = { weight_Y, weight_U, weight_V };
        const char *const func2_names[] = {"weight_Y", "weight_U", "weight_V", NULL };
        double (*func2[])(void *, double, double) = { weight_Y, weight_U, weight_V, p[plane], NULL };

        ret = av_expr_parse(&s->weight_expr[plane], s->weight_str[plane], var_names,
                            NULL, NULL, func2_names, func2, 0, ctx);
        if (ret < 0)
            break;
    }
    return ret;
}

static int config_common(AVFilterLink *inlink)
{
    FFTFILTContext *s = inlink->dst->priv;
    int rdft_hbits, rdft_vbits, i;
    const AVPixFmtDescriptor *desc;

    desc = av_pix_fmt_desc_get(inlink->format);
    for (i = 0; i < desc->nb_components; i++) {
        int w = inlink->w;
        int h = inlink->h;

        /* RDFT - Array initialization for Horizontal pass*/
        for (rdft_hbits = 1; 1 << rdft_hbits < w*10/9; rdft_hbits++);
        s->rdft_hbits[i] = rdft_hbits;
        s->rdft_hlen[i] = 1 << rdft_hbits;
        if (!(s->rdft_hdata[i] = av_malloc_array(h, s->rdft_hlen[i] * sizeof(FFTSample))))
            return AVERROR(ENOMEM);

        /* RDFT - Array initialization for Vertical pass*/
        for (rdft_vbits = 1; 1 << rdft_vbits < h*10/9; rdft_vbits++);
        s->rdft_vbits[i] = rdft_vbits;
        s->rdft_vlen[i] = 1 << rdft_vbits;

        if (!(s->rdft_vdata[i] = av_malloc_array(s->rdft_hlen[i], s->rdft_vlen[i] * sizeof(FFTSample))))
            return AVERROR(ENOMEM);
    }

    return 0;
}

static int config_props(AVFilterLink *inlink)
{
    FFTFILTContext *s = inlink->dst->priv;
    double values[VAR_VARS_NB];
    int i, j, plane, ret;

    ret = config_common(inlink);
    if (ret < 0)
        return ret;

    /*Luminance value - Array initialization*/
    values[VAR_W] = inlink->w;
    values[VAR_H] = inlink->h;
    for (plane = 0; plane < 3; plane++)
    {
        if(!(s->weight[plane] = av_malloc_array(s->rdft_hlen[plane], s->rdft_vlen[plane] * sizeof(double))))
            return AVERROR(ENOMEM);
        for (i = 0; i < s->rdft_hlen[plane]; i++)
        {
            values[VAR_X] = i;
            for (j = 0; j < s->rdft_vlen[plane]; j++)
            {
                values[VAR_Y] = j;
                s->weight[plane][i * s->rdft_vlen[plane] + j] =
                av_expr_eval(s->weight_expr[plane], values, s);
            }
        }
    }
    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
    AVFilterContext *ctx = inlink->dst;
    AVFilterLink *outlink = inlink->dst->outputs[0];
    const AVPixFmtDescriptor *desc;
    FFTFILTContext *s = ctx->priv;
    AVFrame *out;
    int i, j, plane;

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

    av_frame_copy_props(out, in);

    desc = av_pix_fmt_desc_get(inlink->format);
    for (plane = 0; plane < desc->nb_components; plane++) {
        int w = inlink->w;
        int h = inlink->h;

        if (plane == 1 || plane == 2) {
            w = AV_CEIL_RSHIFT(w, desc->log2_chroma_w);
            h = AV_CEIL_RSHIFT(h, desc->log2_chroma_h);
        }

        rdft_horizontal(s, s->rdft_hdata[plane], s->rdft_hlen[plane], in, w, h, plane, 1.f);
        rdft_vertical(s, s->rdft_hdata[plane], s->rdft_vdata[plane],
                      s->rdft_hlen[plane], s->rdft_vlen[plane], h, plane);

        /*Change user defined parameters*/
        for (i = 0; i < s->rdft_hlen[plane]; i++)
            for (j = 0; j < s->rdft_vlen[plane]; j++)
                s->rdft_vdata[plane][i * s->rdft_vlen[plane] + j] *=
                  s->weight[plane][i * s->rdft_vlen[plane] + j];

        s->rdft_vdata[plane][0] += s->rdft_hlen[plane] * s->rdft_vlen[plane] * s->dc[plane];

        irdft_vertical(s, h, plane);
        irdft_horizontal(s, out, w, h, plane);
    }

    av_frame_free(&in);
    return ff_filter_frame(outlink, out);
}

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

    for (i = 0; i < MAX_PLANES; i++) {
        av_free(s->rdft_hdata[i]);
        av_free(s->rdft_vdata[i]);
        av_free(s->rdft_hdata_impulse[i]);
        av_free(s->rdft_vdata_impulse[i]);
        av_expr_free(s->weight_expr[i]);
        av_free(s->weight[i]);
    }

    ff_framesync2_uninit(&s->fs);
}

static int query_formats(AVFilterContext *ctx)
{
    static const enum AVPixelFormat pixel_fmts_fftfilt[] = {
        AV_PIX_FMT_GRAY8,
        AV_PIX_FMT_YUV444P,
        AV_PIX_FMT_NONE
    };

    AVFilterFormats *fmts_list = ff_make_format_list(pixel_fmts_fftfilt);
    if (!fmts_list)
        return AVERROR(ENOMEM);
    return ff_set_common_formats(ctx, fmts_list);
}

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

static const AVFilterPad fftfilt_outputs[] = {
    {
        .name = "default",
        .type = AVMEDIA_TYPE_VIDEO,
    },
    { NULL }
};

AVFilter ff_vf_fftfilt = {
    .name            = "fftfilt",
    .description     = NULL_IF_CONFIG_SMALL("Apply arbitrary expressions to pixels in frequency domain."),
    .priv_size       = sizeof(FFTFILTContext),
    .priv_class      = &fftfilt_class,
    .inputs          = fftfilt_inputs,
    .outputs         = fftfilt_outputs,
    .query_formats   = query_formats,
    .init            = initialize,
    .uninit          = uninit,
};

static const AVOption convolve_options[] = {
    { "planes", "set planes to convolve", OFFSET(planes), AV_OPT_TYPE_INT, {.i64 = 15}, 0, 15, FLAGS },
    { NULL },
};

FRAMESYNC_DEFINE_CLASS(convolve, FFTFILTContext, fs);

static int config_input_impulse(AVFilterLink *inlink)
{
    AVFilterContext *ctx  = inlink->dst;
    FFTFILTContext *s = inlink->dst->priv;
    const AVPixFmtDescriptor *desc;
    int i;

    if (ctx->inputs[0]->w != ctx->inputs[1]->w ||
        ctx->inputs[0]->h != ctx->inputs[1]->h) {
        av_log(ctx, AV_LOG_ERROR, "Width and height of input videos must be same.\n");
        return AVERROR(EINVAL);
    }
    if (ctx->inputs[0]->format != ctx->inputs[1]->format) {
        av_log(ctx, AV_LOG_ERROR, "Inputs must be of same pixel format.\n");
        return AVERROR(EINVAL);
    }

    desc = av_pix_fmt_desc_get(inlink->format);
    for (i = 0; i < desc->nb_components; i++) {
        /* RDFT - Array initialization for Horizontal pass*/
        if (!(s->rdft_hdata_impulse[i] = av_calloc(inlink->h, s->rdft_hlen[i] * sizeof(FFTSample))))
            return AVERROR(ENOMEM);

        /* RDFT - Array initialization for Vertical pass*/
        if (!(s->rdft_vdata_impulse[i] = av_calloc(s->rdft_hlen[i], s->rdft_vlen[i] * sizeof(FFTSample))))
            return AVERROR(ENOMEM);
    }

    return 0;
}

static int do_convolve(FFFrameSync *fs)
{
    AVFilterContext *ctx = fs->parent;
    AVFilterLink *outlink = ctx->outputs[0];
    const AVPixFmtDescriptor *desc;
    FFTFILTContext *s = ctx->priv;
    AVFrame *mainpic = NULL, *impulsepic = NULL;
    int ret, i, j, plane;

    ret = ff_framesync2_dualinput_get(fs, &mainpic, &impulsepic);
    if (ret < 0)
        return ret;
    if (!impulsepic)
        return ff_filter_frame(ctx->outputs[0], mainpic);

    desc = av_pix_fmt_desc_get(outlink->format);
    for (plane = 0; plane < desc->nb_components; plane++) {
        int w = outlink->w;
        int h = outlink->h;

        if (plane == 1 || plane == 2) {
            w = AV_CEIL_RSHIFT(w, desc->log2_chroma_w);
            h = AV_CEIL_RSHIFT(h, desc->log2_chroma_h);
        }

        rdft_horizontal(s, s->rdft_hdata[plane], s->rdft_hlen[plane], mainpic, w, h, plane, 1.f);
        rdft_vertical(s, s->rdft_hdata[plane], s->rdft_vdata[plane],
                      s->rdft_hlen[plane], s->rdft_vlen[plane], h, plane);

        rdft_horizontal(s, s->rdft_hdata_impulse[plane], s->rdft_hlen[plane], impulsepic, w, h, plane, 1/(7*255.f));
        rdft_vertical(s, s->rdft_hdata_impulse[plane], s->rdft_vdata_impulse[plane],
                      s->rdft_hlen[plane], s->rdft_vlen[plane], h, plane);

        for (i = 0; i < outlink->h; i++) {
            for (j = 0; j < outlink->w; j++) {
                FFTSample re, im;
                FFTSample ire, iim;

                re = s->rdft_vdata[plane][i * s->rdft_vlen[plane] + 2 * j];
                im = s->rdft_vdata[plane][i * s->rdft_vlen[plane] + 2 * j + 1];
                ire = s->rdft_vdata_impulse[plane][i * s->rdft_vlen[plane] + 2 * j];
                iim = s->rdft_vdata_impulse[plane][i * s->rdft_vlen[plane] + 2 * j + 1];
                s->rdft_vdata[plane][i * s->rdft_vlen[plane] + 2 * j    ] = re * ire - im * iim;
                s->rdft_vdata[plane][i * s->rdft_vlen[plane] + 2 * j + 1] = re * iim + im * ire;
            }
        }

        irdft_vertical(s, h, plane);
        irdft_horizontal(s, mainpic, w, h, plane);
    }

    return ff_filter_frame(outlink, mainpic);
}

static int config_output(AVFilterLink *outlink)
{
    AVFilterContext *ctx = outlink->src;
    FFTFILTContext *s = ctx->priv;
    AVFilterLink *mainlink = ctx->inputs[0];
    int ret;

    s->fs.on_event = do_convolve;
    ret = ff_framesync2_init_dualinput(&s->fs, ctx);
    if (ret < 0)
        return ret;
    outlink->w = mainlink->w;
    outlink->h = mainlink->h;
    outlink->time_base = mainlink->time_base;
    outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
    outlink->frame_rate = mainlink->frame_rate;

    if ((ret = ff_framesync2_configure(&s->fs)) < 0)
        return ret;

    return 0;
}

static int activate(AVFilterContext *ctx)
{
    FFTFILTContext *s = ctx->priv;
    return ff_framesync2_activate(&s->fs);
}

static int convolve_query_formats(AVFilterContext *ctx)
{
    static const enum AVPixelFormat pixel_fmts_fftfilt[] = {
        AV_PIX_FMT_GRAY8,
        AV_PIX_FMT_GBRP,
        AV_PIX_FMT_YUV444P,
        AV_PIX_FMT_NONE
    };

    AVFilterFormats *fmts_list = ff_make_format_list(pixel_fmts_fftfilt);
    if (!fmts_list)
        return AVERROR(ENOMEM);
    return ff_set_common_formats(ctx, fmts_list);
}

static const AVFilterPad convolve_inputs[] = {
    {
        .name          = "main",
        .type          = AVMEDIA_TYPE_VIDEO,
        .config_props  = config_common,
    },{
        .name          = "impulse",
        .type          = AVMEDIA_TYPE_VIDEO,
        .config_props  = config_input_impulse,
    },
    { NULL }
};

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

AVFilter ff_vf_convolve = {
    .name          = "convolve",
    .description   = NULL_IF_CONFIG_SMALL("Convolve first video stream with second video stream."),
    .preinit       = convolve_framesync_preinit,
    .uninit        = uninit,
    .query_formats = convolve_query_formats,
    .activate      = activate,
    .priv_size     = sizeof(FFTFILTContext),
    .priv_class    = &convolve_class,
    .inputs        = convolve_inputs,
    .outputs       = convolve_outputs,
};