/*****************************************************************************
 * transform.c : transform image module for vlc
 *****************************************************************************
 * Copyright (C) 2000-2006 VLC authors and VideoLAN
 * Copyright (C) 2010 Laurent Aimar
 * Copyright (C) 2012 Rémi Denis-Courmont
 *
 * Authors: Samuel Hocevar <sam@zoy.org>
 *          Laurent Aimar <fenrir _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.
 *****************************************************************************/

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

#ifdef HAVE_CONFIG_H
#   include "config.h"
#endif
#include <limits.h>

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_filter.h>

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  Open (vlc_object_t *);
static void Close(vlc_object_t *);

#define CFG_PREFIX "transform-"

#define TYPE_TEXT N_("Transform type")
static const char * const type_list[] = { "90", "180", "270",
    "hflip", "vflip", "transpose", "antitranspose" };
static const char * const type_list_text[] = { N_("Rotate by 90 degrees"),
    N_("Rotate by 180 degrees"), N_("Rotate by 270 degrees"),
    N_("Flip horizontally"), N_("Flip vertically"),
    N_("Transpose"), N_("Anti-transpose") };

vlc_module_begin()
    set_description(N_("Video transformation filter"))
    set_shortname(N_("Transformation"))
    set_help(N_("Rotate or flip the video"))
    set_capability("video filter2", 0)
    set_category(CAT_VIDEO)
    set_subcategory(SUBCAT_VIDEO_VFILTER)

    add_string(CFG_PREFIX "type", "90", TYPE_TEXT, TYPE_TEXT, false)
        change_string_list(type_list, type_list_text)
        change_safe()

    add_shortcut("transform")
    set_callbacks(Open, Close)
vlc_module_end()

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static void HFlip(int *sx, int *sy, int w, int h, int dx, int dy)
{
    VLC_UNUSED( h );
    *sx = w - 1 - dx;
    *sy = dy;
}
static void VFlip(int *sx, int *sy, int w, int h, int dx, int dy)
{
    VLC_UNUSED( w );
    *sx = dx;
    *sy = h - 1 - dy;
}
static void Transpose(int *sx, int *sy, int w, int h, int dx, int dy)
{
    VLC_UNUSED( h ); VLC_UNUSED( w );
    *sx = dy;
    *sy = dx;
}
static void AntiTranspose(int *sx, int *sy, int w, int h, int dx, int dy)
{
    *sx = h - 1 - dy;
    *sy = w - 1 - dx;
}
static void R90(int *sx, int *sy, int w, int h, int dx, int dy)
{
    VLC_UNUSED( h );
    *sx = dy;
    *sy = w - 1 - dx;
}
static void R180(int *sx, int *sy, int w, int h, int dx, int dy)
{
    *sx = w - dx;
    *sy = h - dy;
}
static void R270(int *sx, int *sy, int w, int h, int dx, int dy)
{
    VLC_UNUSED( w );
    *sx = h - 1 - dy;
    *sy = dx;
}
typedef void (*convert_t)(int *, int *, int, int, int, int);

#define PLANE(f,bits) \
static void Plane##bits##_##f(plane_t *restrict dst, const plane_t *restrict src) \
{ \
    const uint##bits##_t *src_pixels = (const void *)src->p_pixels; \
    uint##bits##_t *restrict dst_pixels = (void *)dst->p_pixels; \
    const unsigned src_width = src->i_pitch / sizeof (*src_pixels); \
    const unsigned dst_width = dst->i_pitch / sizeof (*dst_pixels); \
    const unsigned dst_visible_width = dst->i_visible_pitch / sizeof (*dst_pixels); \
 \
    for (int y = 0; y < dst->i_visible_lines; y++) { \
        for (unsigned x = 0; x < dst_visible_width; x++) { \
            int sx, sy; \
            (f)(&sx, &sy, dst_visible_width, dst->i_visible_lines, x, y); \
            dst_pixels[y * dst_width + x] = \
                src_pixels[sy * src_width + sx]; \
        } \
    } \
}

static void Plane_VFlip(plane_t *restrict dst, const plane_t *restrict src)
{
    const uint8_t *src_pixels = src->p_pixels;
    uint8_t *restrict dst_pixels = dst->p_pixels;

    dst_pixels += dst->i_pitch * dst->i_visible_lines;
    for (int y = 0; y < dst->i_visible_lines; y++) {
        dst_pixels -= dst->i_pitch;
        memcpy(dst_pixels, src_pixels, dst->i_visible_pitch);
        src_pixels += src->i_pitch;
    }
}

#define YUY2(f) \
static void PlaneYUY2_##f(plane_t *restrict dst, const plane_t *restrict src) \
{ \
    unsigned dst_visible_width = dst->i_visible_pitch / 2; \
 \
    for (int y = 0; y < dst->i_visible_lines; y += 2) { \
        for (unsigned x = 0; x < dst_visible_width; x+= 2) { \
            int sx0, sy0, sx1, sy1; \
            (f)(&sx0, &sy0, dst_visible_width, dst->i_visible_lines, x, y); \
            (f)(&sx1, &sy1, dst_visible_width, dst->i_visible_lines, \
                x + 1, y + 1); \
            dst->p_pixels[(y + 0) * dst->i_pitch + 2 * (x + 0)] = \
                src->p_pixels[sy0 * src->i_pitch + 2 * sx0]; \
            dst->p_pixels[(y + 0) * dst->i_pitch + 2 * (x + 1)] = \
                src->p_pixels[sy1 * src->i_pitch + 2 * sx0]; \
            dst->p_pixels[(y + 1) * dst->i_pitch + 2 * (x + 0)] = \
                src->p_pixels[sy0 * src->i_pitch + 2 * sx1]; \
            dst->p_pixels[(y + 1) * dst->i_pitch + 2 * (x + 1)] = \
                src->p_pixels[sy1 * src->i_pitch + 2 * sx1]; \
 \
            int sx, sy, u, v; \
            (f)(&sx, &sy, dst_visible_width / 2, dst->i_visible_lines / 2, \
                x / 2, y / 2); \
            u = (1 + src->p_pixels[2 * sy * src->i_pitch + 4 * sx + 1] + \
                src->p_pixels[(2 * sy + 1) * src->i_pitch + 4 * sx + 1]) / 2; \
            v = (1 + src->p_pixels[2 * sy * src->i_pitch + 4 * sx + 3] + \
                src->p_pixels[(2 * sy + 1) * src->i_pitch + 4 * sx + 3]) / 2; \
            dst->p_pixels[(y + 0) * dst->i_pitch + 2 * x + 1] = u; \
            dst->p_pixels[(y + 0) * dst->i_pitch + 2 * x + 3] = v; \
            dst->p_pixels[(y + 1) * dst->i_pitch + 2 * x + 1] = u; \
            dst->p_pixels[(y + 1) * dst->i_pitch + 2 * x + 3] = v; \
        } \
    } \
}

#define PLANES(f) \
PLANE(f,8) PLANE(f,16) PLANE(f,32)

PLANES(HFlip)
#define Plane8_VFlip Plane_VFlip
#define Plane16_VFlip Plane_VFlip
#define Plane32_VFlip Plane_VFlip
PLANES(Transpose)
PLANES(AntiTranspose)
PLANES(R90)
PLANES(R180)
PLANES(R270)

#define PlaneYUY2_HFlip Plane32_HFlip
#define PlaneYUY2_VFlip Plane_VFlip
#define PlaneYUY2_R180  Plane32_R180
YUY2(Transpose)
YUY2(AntiTranspose)
YUY2(R90)
YUY2(R270)

typedef struct {
    char      name[16];
    convert_t convert;
    convert_t iconvert;
    void      (*plane8) (plane_t *dst, const plane_t *src);
    void      (*plane16)(plane_t *dst, const plane_t *src);
    void      (*plane32)(plane_t *dst, const plane_t *src);
    void      (*yuyv)(plane_t *dst, const plane_t *src);
} transform_description_t;

#define DESC(str, f, invf) \
    { str, f, invf, Plane8_##f, Plane16_##f, Plane32_##f, PlaneYUY2_##f }

static const transform_description_t descriptions[] = {
    DESC("90",            R90,           R270),
    DESC("180",           R180,          R180),
    DESC("270",           R270,          R90),
    DESC("hflip",         HFlip,         HFlip),
    DESC("vflip",         VFlip,         VFlip),
    DESC("transpose",     Transpose,     Transpose),
    DESC("antitranspose", AntiTranspose, AntiTranspose),
};

static bool dsc_is_rotated(const transform_description_t *dsc)
{
    return dsc->plane32 != dsc->yuyv;
}

static const size_t n_transforms =
    sizeof (descriptions) / sizeof (descriptions[0]);

struct filter_sys_t {
    const vlc_chroma_description_t *chroma;
    void (*plane)(plane_t *, const plane_t *);
    convert_t convert;
};

static picture_t *Filter(filter_t *filter, picture_t *src)
{
    filter_sys_t *sys = filter->p_sys;

    picture_t *dst = filter_NewPicture(filter);
    if (!dst) {
        picture_Release(src);
        return NULL;
    }

    const vlc_chroma_description_t *chroma = sys->chroma;
    for (unsigned i = 0; i < chroma->plane_count; i++)
         sys->plane(&dst->p[i], &src->p[i]);

    picture_CopyProperties(dst, src);
    picture_Release(src);
    return dst;
}

static int Mouse(filter_t *filter, vlc_mouse_t *mouse,
                 const vlc_mouse_t *mold, const vlc_mouse_t *mnew)
{
    VLC_UNUSED( mold );

    const video_format_t *fmt = &filter->fmt_out.video;
    const filter_sys_t   *sys = filter->p_sys;

    *mouse = *mnew;
    sys->convert(&mouse->i_x, &mouse->i_y,
                 fmt->i_visible_width, fmt->i_visible_height,
                 mouse->i_x, mouse->i_y);
    return VLC_SUCCESS;
}

static int Open(vlc_object_t *object)
{
    filter_t *filter = (filter_t *)object;
    const video_format_t *src = &filter->fmt_in.video;
    video_format_t       *dst = &filter->fmt_out.video;

    const vlc_chroma_description_t *chroma =
        vlc_fourcc_GetChromaDescription(src->i_chroma);
    if (chroma == NULL)
        return VLC_EGENERIC;

    filter_sys_t *sys = malloc(sizeof(*sys));
    if (!sys)
        return VLC_ENOMEM;

    sys->chroma = chroma;

    char *type_name = var_InheritString(filter, CFG_PREFIX"type");
    const transform_description_t *dsc = NULL;

    for (size_t i = 0; i < n_transforms; i++)
        if (type_name && !strcmp(descriptions[i].name, type_name)) {
            dsc = &descriptions[i];
            break;
        }
    if (dsc == NULL) {
        dsc = &descriptions[0];
        msg_Warn(filter, "No valid transform mode provided, using '%s'",
                 dsc->name);
    }

    free(type_name);

    switch (chroma->pixel_size) {
        case 1:
            sys->plane = dsc->plane8;
            break;
        case 2:
            sys->plane = dsc->plane16;
            break;
        case 4:
            sys->plane = dsc->plane32;
            break;
        default:
            msg_Err(filter, "Unsupported pixel size %u (chroma %4.4s)",
                    chroma->pixel_size, (char *)&src->i_chroma);
            goto error;
    }

    sys->convert = dsc->convert;
    if (dsc_is_rotated(dsc)) {
        for (unsigned i = 0; i < chroma->plane_count; i++) {
            if (chroma->p[i].w.num * chroma->p[i].h.den
             != chroma->p[i].h.num * chroma->p[i].w.den) {
                msg_Err(filter, "Format rotation not possible (chroma %4.4s)",
                        (char *)&src->i_chroma); /* I422... */
                goto error;
            }
        }

        if (!filter->b_allow_fmt_out_change) {
            msg_Err(filter, "Format change is not allowed");
            goto error;
        }

        dst->i_width          = src->i_height;
        dst->i_visible_width  = src->i_visible_height;
        dst->i_height         = src->i_width;
        dst->i_visible_height = src->i_visible_width;
        dst->i_sar_num        = src->i_sar_den;
        dst->i_sar_den        = src->i_sar_num;
    }

    /* Deal with weird packed formats */
    switch (src->i_chroma) {
        case VLC_CODEC_UYVY:
        case VLC_CODEC_VYUY:
            if (dsc_is_rotated(dsc)) {
                msg_Err(filter, "Format rotation not possible (chroma %4.4s)",
                        (char *)&src->i_chroma);
                goto error;
            }
            /* fallthrough */
        case VLC_CODEC_YUYV:
        case VLC_CODEC_YVYU:
            sys->plane = dsc->yuyv; /* 32-bits, not 16-bits! */
            break;
        case VLC_CODEC_NV12:
        case VLC_CODEC_NV21:
            goto error;
    }

    dst->i_x_offset       = INT_MAX;
    dst->i_y_offset       = INT_MAX;
    for (int i = 0; i < 2; i++) {
        int tx, ty;
        dsc->iconvert(&tx, &ty, src->i_width, src->i_height,
                      src->i_x_offset + i * (src->i_visible_width  - 1),
                      src->i_y_offset + i * (src->i_visible_height - 1));
        dst->i_x_offset = __MIN(dst->i_x_offset, (unsigned)(1 + tx));
        dst->i_y_offset = __MIN(dst->i_y_offset, (unsigned)(1 + ty));
    }

    filter->p_sys           = sys;
    filter->pf_video_filter = Filter;
    filter->pf_video_mouse  = Mouse;
    return VLC_SUCCESS;
error:
    free(sys);
    return VLC_EGENERIC;
}

static void Close(vlc_object_t *object)
{
    filter_t     *filter = (filter_t *)object;
    filter_sys_t *sys    = filter->p_sys;

    free(sys);
}
