/*****************************************************************************
 * sharpen.c: Sharpen video filter
 *****************************************************************************
 * Copyright (C) 2003-2007 VLC authors and VideoLAN
 *
 * Author: Jérémy DEMEULE <dj_mulder at djduron dot no-ip dot org>
 *         Jean-Baptiste Kempf <jb at videolan dot org>
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/* The sharpen filter. */
/*
 * static int filter[] = { -1, -1, -1,
 *                         -1,  8, -1,
 *                         -1, -1, -1 };
 */

/*****************************************************************************
 * Preamble
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>
#include <stdatomic.h>
#include <vlc_common.h>
#include <vlc_configuration.h>
#include <vlc_plugin.h>
#include <vlc_filter.h>
#include <vlc_picture.h>

#define SIG_TEXT N_("Sharpen strength (0-2)")
#define SIG_LONGTEXT N_("Set the Sharpen strength, between 0 and 2. Defaults to 0.05.")

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Create    ( filter_t * );

static int SharpenCallback( vlc_object_t *, char const *,
                            vlc_value_t, vlc_value_t, void * );
VIDEO_FILTER_WRAPPER_CLOSE(Filter, Destroy)

#define SHARPEN_HELP N_("Augment contrast between contours.")
#define FILTER_PREFIX "sharpen-"

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
vlc_module_begin ()
    set_description( N_("Sharpen video filter") )
    set_shortname( N_("Sharpen") )
    set_help(SHARPEN_HELP)
    set_subcategory( SUBCAT_VIDEO_VFILTER )
    add_float_with_range( FILTER_PREFIX "sigma", 0.05, 0.0, 2.0,
        SIG_TEXT, SIG_LONGTEXT )
    change_safe()
    add_shortcut( "sharpen" )
    set_callback_video_filter( Create )
vlc_module_end ()

static const char *const ppsz_filter_options[] = {
    "sigma", NULL
};

/*****************************************************************************
 * filter_sys_t: Sharpen video filter descriptor
 *****************************************************************************
 * This structure is part of the video output thread descriptor.
 * It describes the Sharpen specific properties of an output thread.
 *****************************************************************************/

typedef struct
{
    atomic_int sigma;
} filter_sys_t;

/*****************************************************************************
 * Create: allocates Sharpen video thread output method
 *****************************************************************************
 * This function allocates and initializes a Sharpen vout method.
 *****************************************************************************/
static int Create( filter_t *p_filter )
{
    const vlc_fourcc_t fourcc = p_filter->fmt_in.video.i_chroma;
    const vlc_chroma_description_t *p_chroma = vlc_fourcc_GetChromaDescription( fourcc );
    if( !p_chroma || p_chroma->plane_count != 3 ||
        (p_chroma->pixel_size != 1 &&
         p_filter->fmt_in.video.i_chroma != VLC_CODEC_I420_10L &&
         p_filter->fmt_in.video.i_chroma != VLC_CODEC_I420_10B)) {
        msg_Dbg( p_filter, "Unsupported chroma (%4.4s)", (char*)&fourcc );
        return VLC_EGENERIC;
    }

    /* Allocate structure */
    filter_sys_t *p_sys = malloc( sizeof( filter_sys_t ) );
    if( p_sys == NULL )
        return VLC_ENOMEM;
    p_filter->p_sys = p_sys;

    p_filter->ops = &Filter_ops;

    config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
                   p_filter->p_cfg );

    atomic_init(&p_sys->sigma,
                var_CreateGetFloatCommand(p_filter, FILTER_PREFIX "sigma")
                * (1 << 20));

    var_AddCallback( p_filter, FILTER_PREFIX "sigma",
                     SharpenCallback, p_sys );

    return VLC_SUCCESS;
}


/*****************************************************************************
 * Destroy: destroy Sharpen video thread output method
 *****************************************************************************
 * Terminate an output method created by SharpenCreateOutputMethod
 *****************************************************************************/
static void Destroy( filter_t *p_filter )
{
    filter_sys_t *p_sys = p_filter->p_sys;

    var_DelCallback( p_filter, FILTER_PREFIX "sigma", SharpenCallback, p_sys );
    free( p_sys );
}

/*****************************************************************************
 * Render: displays previously rendered output
 *****************************************************************************
 * This function send the currently rendered image to Invert image, waits
 * until it is displayed and switch the two rendering buffers, preparing next
 * frame.
 *****************************************************************************/

#define IS_YUV_420_10BITS(fmt) (fmt == VLC_CODEC_I420_10L ||    \
                                fmt == VLC_CODEC_I420_10B)

#define SHARPEN_FRAME(maxval, data_t)                                   \
    do                                                                  \
    {                                                                   \
        assert((maxval) >= 0);                                          \
        data_t *restrict p_src = (data_t *)p_pic->p[Y_PLANE].p_pixels;  \
        data_t *restrict p_out = (data_t *)p_outpic->p[Y_PLANE].p_pixels; \
        const unsigned data_sz = sizeof(data_t);                        \
        const int i_src_line_len = p_pic->p[Y_PLANE].i_pitch / data_sz; \
        const int i_out_line_len = p_outpic->p[Y_PLANE].i_pitch / data_sz; \
        const int sigma = atomic_load(&p_sys->sigma);         \
                                                                        \
        memcpy(p_out, p_src, i_visible_pitch);                          \
                                                                        \
        for( unsigned i = 1; i < i_visible_lines - 1; i++ )             \
        {                                                               \
            p_out[i * i_out_line_len] = p_src[i * i_src_line_len];      \
                                                                        \
            for( unsigned j = data_sz; j < i_visible_pitch - 1; j++ )   \
            {                                                           \
                const int line_idx_1 = (i - 1) * i_src_line_len;        \
                const int line_idx_2 = i * i_src_line_len;              \
                const int line_idx_3 = (i + 1) * i_src_line_len;        \
                int pix =                                               \
                    (p_src[line_idx_1 + j - 1] * v1) +                  \
                    (p_src[line_idx_1 + j    ] * v1) +                  \
                    (p_src[line_idx_1 + j + 1] * v1) +                  \
                    (p_src[line_idx_2 + j - 1] * v1) +                  \
                    (p_src[line_idx_2 + j    ] << v2) +                 \
                    (p_src[line_idx_2 + j + 1] * v1) +                  \
                    (p_src[line_idx_3 + j - 1] * v1) +                  \
                    (p_src[line_idx_3 + j    ] * v1) +                  \
                    (p_src[line_idx_3 + j + 1] * v1);                   \
                                                                        \
                pix = (VLC_CLIP(pix, -(maxval), maxval) * sigma) >> 20; \
                p_out[i * i_out_line_len + j] =                         \
                    VLC_CLIP( p_src[line_idx_2 + j] + pix, 0, maxval);  \
            }                                                           \
            p_out[i * i_out_line_len + i_visible_pitch / data_sz - 1] = \
                p_src[i * i_src_line_len + i_visible_pitch / data_sz - 1];  \
        }                                                               \
        memcpy(&p_out[(i_visible_lines - 1) * i_out_line_len],          \
               &p_src[(i_visible_lines - 1) * i_src_line_len],          \
               i_visible_pitch);                                        \
    } while (0)

static void Filter( filter_t *p_filter, picture_t *p_pic, picture_t *p_outpic )
{
    const int v1 = -1;
    const int v2 = 3; /* 2^3 = 8 */
    const unsigned i_visible_lines = p_pic->p[Y_PLANE].i_visible_lines;
    const unsigned i_visible_pitch = p_pic->p[Y_PLANE].i_visible_pitch;

    filter_sys_t *p_sys = p_filter->p_sys;

    if (!IS_YUV_420_10BITS(p_pic->format.i_chroma))
        SHARPEN_FRAME(255, uint8_t);
    else
        SHARPEN_FRAME(1023, uint16_t);

    plane_CopyPixels( &p_outpic->p[U_PLANE], &p_pic->p[U_PLANE] );
    plane_CopyPixels( &p_outpic->p[V_PLANE], &p_pic->p[V_PLANE] );
}

static int SharpenCallback( vlc_object_t *p_this, char const *psz_var,
                            vlc_value_t oldval, vlc_value_t newval,
                            void *p_data )
{
    VLC_UNUSED(p_this); VLC_UNUSED(oldval); VLC_UNUSED(psz_var);
    filter_sys_t *p_sys = p_data;

    atomic_store(&p_sys->sigma,
                 VLC_CLIP(newval.f_float, 0.f, 2.f) * (1 << 20));

    return VLC_SUCCESS;
}
