PeerStreamer

/*

 * Ported to FFmpeg from MPlayer libmpcodecs/unsharp.c

 * 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

 *

 * 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 "libavutil/common.h"

#include "libavutil/mem.h"

#include "libavutil/pixdesc.h"

#define MIN_SIZE 3

#define MAX_SIZE 13

#define CHROMA_WIDTH(link)  -((-link->w) >> av_pix_fmt_descriptors[link->format].log2_chroma_w)

#define CHROMA_HEIGHT(link) -((-link->h) >> av_pix_fmt_descriptors[link->format].log2_chroma_h)

typedef struct FilterParam {

    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 *sc[(MAX_SIZE * MAX_SIZE) - 1]; ///< finite state machine storage

} FilterParam;

typedef struct {

    FilterParam luma;   ///< luma parameters (width, height, amount)

    FilterParam chroma; ///< chroma parameters (width, height, amount)

} UnsharpContext;

static void unsharpen(uint8_t *dst, uint8_t *src, int dst_stride, int src_stride, int width, int height, FilterParam *fp)

{

    uint32_t **sc = fp->sc;

    uint32_t sr[(MAX_SIZE * MAX_SIZE) - 1], tmp1, tmp2;

    int32_t res;

    int x, y, z;

    if (!fp->amount) {

        if (dst_stride == src_stride)

            memcpy(dst, src, src_stride * height);

        else

            for (y = 0; y < height; y++, dst += dst_stride, src += src_stride)

                memcpy(dst, src, width);

        return;

    }

    for (y = 0; y < 2 * fp->steps_y; y++)

        memset(sc[y], 0, sizeof(sc[y][0]) * (width + 2 * fp->steps_x));

    for (y = -fp->steps_y; y < height + fp->steps_y; y++) {

        memset(sr, 0, sizeof(sr[0]) * (2 * fp->steps_x - 1));

        for (x = -fp->steps_x; x < width + fp->steps_x; x++) {

            tmp1 = x <= 0 ? src[0] : x >= width ? src[width-1] : src[x];

            for (z = 0; z < fp->steps_x * 2; z += 2) {

                tmp2 = sr[z + 0] + tmp1; sr[z + 0] = tmp1;

                tmp1 = sr[z + 1] + tmp2; sr[z + 1] = tmp2;

            }

            for (z = 0; z < fp->steps_y * 2; z += 2) {

                tmp2 = sc[z + 0][x + fp->steps_x] + tmp1; sc[z + 0][x + fp->steps_x] = tmp1;

                tmp1 = sc[z + 1][x + fp->steps_x] + tmp2; sc[z + 1][x + fp->steps_x] = tmp2;

            }

            if (x >= fp->steps_x && y >= fp->steps_y) {

                uint8_t* srx = src - fp->steps_y * src_stride + x - fp->steps_x;

                uint8_t* dsx = dst - fp->steps_y * dst_stride + x - fp->steps_x;

                res = (int32_t)*srx + ((((int32_t) * srx - (int32_t)((tmp1 + fp->halfscale) >> fp->scalebits)) * fp->amount) >> 16);

                *dsx = av_clip_uint8(res);

            }

        }

        if (y >= 0) {

            dst += dst_stride;

            src += src_stride;

        }

    }

}

static void set_filter_param(FilterParam *fp, int msize_x, int msize_y, double 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);

}

static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)

{

    UnsharpContext *unsharp = ctx->priv;

    int lmsize_x = 5, cmsize_x = 0;

    int lmsize_y = 5, cmsize_y = 0;

    double lamount = 1.0f, camount = 0.0f;

    if (args)

        sscanf(args, "%d:%d:%lf:%d:%d:%lf", &lmsize_x, &lmsize_y, &lamount,

                                            &cmsize_x, &cmsize_y, &camount);

    set_filter_param(&unsharp->luma,   lmsize_x, lmsize_y, lamount);

    set_filter_param(&unsharp->chroma, cmsize_x, cmsize_y, camount);

    return 0;

}

static int query_formats(AVFilterContext *ctx)

{

    enum PixelFormat pix_fmts[] = {

        PIX_FMT_YUV420P,  PIX_FMT_YUV422P,  PIX_FMT_YUV444P,  PIX_FMT_YUV410P,

        PIX_FMT_YUV411P,  PIX_FMT_YUV440P,  PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P,

        PIX_FMT_YUVJ444P, PIX_FMT_YUVJ440P, PIX_FMT_NONE

    };

    avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));

    return 0;

}

static void init_filter_param(AVFilterContext *ctx, FilterParam *fp, const char *effect_type, int width)

{

    int z;

    const char *effect;

    effect = fp->amount == 0 ? "none" : fp->amount < 0 ? "blur" : "sharpen";

    av_log(ctx, AV_LOG_INFO, "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);

    for (z = 0; z < 2 * fp->steps_y; z++)

        fp->sc[z] = av_malloc(sizeof(*(fp->sc[z])) * (width + 2 * fp->steps_x));

}

static int config_props(AVFilterLink *link)

{

    UnsharpContext *unsharp = link->dst->priv;

    init_filter_param(link->dst, &unsharp->luma,   "luma",   link->w);

    init_filter_param(link->dst, &unsharp->chroma, "chroma", CHROMA_WIDTH(link));

    return 0;

}

static void free_filter_param(FilterParam *fp)

{

    int z;

    for (z = 0; z < 2 * fp->steps_y; z++)

        av_free(fp->sc[z]);

}

static av_cold void uninit(AVFilterContext *ctx)

{

    UnsharpContext *unsharp = ctx->priv;

    free_filter_param(&unsharp->luma);

    free_filter_param(&unsharp->chroma);

}

static void end_frame(AVFilterLink *link)

{

    UnsharpContext *unsharp = link->dst->priv;

    AVFilterBufferRef *in  = link->cur_buf;

    AVFilterBufferRef *out = link->dst->outputs[0]->out_buf;

    unsharpen(out->data[0], in->data[0], out->linesize[0], in->linesize[0], link->w,            link->h,             &unsharp->luma);

    unsharpen(out->data[1], in->data[1], out->linesize[1], in->linesize[1], CHROMA_WIDTH(link), CHROMA_HEIGHT(link), &unsharp->chroma);

    unsharpen(out->data[2], in->data[2], out->linesize[2], in->linesize[2], CHROMA_WIDTH(link), CHROMA_HEIGHT(link), &unsharp->chroma);

    avfilter_unref_buffer(in);

    avfilter_draw_slice(link->dst->outputs[0], 0, link->h, 1);

    avfilter_end_frame(link->dst->outputs[0]);

    avfilter_unref_buffer(out);

}

static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)

{

}

AVFilter avfilter_vf_unsharp = {

    .name      = "unsharp",

    .description = NULL_IF_CONFIG_SMALL("Sharpen or blur the input video."),

    .priv_size = sizeof(UnsharpContext),

    .init = init,

    .uninit = uninit,

    .query_formats = query_formats,

    .inputs    = (AVFilterPad[]) {{ .name             = "default",

                                    .type             = AVMEDIA_TYPE_VIDEO,

                                    .draw_slice       = draw_slice,

                                    .end_frame        = end_frame,

                                    .config_props     = config_props,

                                    .min_perms        = AV_PERM_READ, },

                                  { .name = NULL}},

    .outputs   = (AVFilterPad[]) {{ .name             = "default",

                                    .type             = AVMEDIA_TYPE_VIDEO, },

                                  { .name = NULL}},

};