/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
/* based on the Area Based Deinterlacer (for RGB frames)        */
/* (a VirtualDub filter) from Gunnar Thalin <guth@home.se>      */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <gst/gst.h>
#include <gst/video/video.h>
#include "gstdeinterlace.h"

/* these macros are adapted from videotestsrc, paint_setup_I420() */
#define ROUND_UP_2(x)  (((x)+1)&~1)
#define ROUND_UP_4(x)  (((x)+3)&~3)
#define ROUND_UP_8(x)  (((x)+7)&~7)

#define GST_VIDEO_I420_Y_ROWSTRIDE(width) (ROUND_UP_4(width))
#define GST_VIDEO_I420_U_ROWSTRIDE(width) (ROUND_UP_8(width)/2)
#define GST_VIDEO_I420_V_ROWSTRIDE(width) ((ROUND_UP_8(GST_VIDEO_I420_Y_ROWSTRIDE(width)))/2)

#define GST_VIDEO_I420_Y_OFFSET(w,h) (0)
#define GST_VIDEO_I420_U_OFFSET(w,h) (GST_VIDEO_I420_Y_OFFSET(w,h)+(GST_VIDEO_I420_Y_ROWSTRIDE(w)*ROUND_UP_2(h)))
#define GST_VIDEO_I420_V_OFFSET(w,h) (GST_VIDEO_I420_U_OFFSET(w,h)+(GST_VIDEO_I420_U_ROWSTRIDE(w)*ROUND_UP_2(h)/2))

#define GST_VIDEO_I420_SIZE(w,h) (GST_VIDEO_I420_V_OFFSET(w,h)+(GST_VIDEO_I420_V_ROWSTRIDE(w)*ROUND_UP_2(h)/2))

/* elementfactory information */
static const GstElementDetails deinterlace_details =
GST_ELEMENT_DETAILS ("Deinterlace",
    "Filter/Effect/Video",
    "Deinterlace video",
    "Wim Taymans <wim.taymans@chello.be>");


/* Filter signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  ARG_0,
  ARG_DI_ONLY,
  ARG_BLEND,
  ARG_THRESHOLD,
  ARG_EDGE_DETECT
};

static GstStaticPadTemplate deinterlace_src_factory =
GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
    );

static GstStaticPadTemplate deinterlace_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
    );

static GType gst_deinterlace_get_type (void);

static void gst_deinterlace_base_init (gpointer g_class);
static void gst_deinterlace_class_init (GstDeInterlaceClass * klass);
static void gst_deinterlace_init (GstDeInterlace * filter);

static void gst_deinterlace_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_deinterlace_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static void gst_deinterlace_chain (GstPad * pad, GstData * _data);

static GstElementClass *parent_class = NULL;

/*static guint gst_filter_signals[LAST_SIGNAL] = { 0 }; */

static GType
gst_deinterlace_get_type (void)
{
  static GType deinterlace_type = 0;

  if (!deinterlace_type) {
    static const GTypeInfo deinterlace_info = {
      sizeof (GstDeInterlaceClass),
      gst_deinterlace_base_init,
      NULL,
      (GClassInitFunc) gst_deinterlace_class_init,
      NULL,
      NULL,
      sizeof (GstDeInterlace),
      0,
      (GInstanceInitFunc) gst_deinterlace_init,
    };

    deinterlace_type =
        g_type_register_static (GST_TYPE_ELEMENT, "GstDeInterlace",
        &deinterlace_info, 0);
  }
  return deinterlace_type;
}

static void
gst_deinterlace_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&deinterlace_src_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&deinterlace_sink_factory));

  gst_element_class_set_details (element_class, &deinterlace_details);
}

static void
gst_deinterlace_class_init (GstDeInterlaceClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_DI_ONLY, g_param_spec_boolean ("di_area_only", "di_area_only", "di_area_only", TRUE, G_PARAM_READWRITE));        /* CHECKME */
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_BLEND, g_param_spec_boolean ("blend", "blend", "blend", TRUE, G_PARAM_READWRITE));       /* CHECKME */
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_THRESHOLD, g_param_spec_int ("threshold", "threshold", "threshold", G_MININT, G_MAXINT, 0, G_PARAM_READWRITE));  /* CHECKME */
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_EDGE_DETECT, g_param_spec_int ("edge_detect", "edge_detect", "edge_detect", G_MININT, G_MAXINT, 0, G_PARAM_READWRITE));  /* CHECKME */

  gobject_class->set_property = gst_deinterlace_set_property;
  gobject_class->get_property = gst_deinterlace_get_property;
}
static GstCaps *
gst_deinterlace_getcaps (GstPad * pad)
{
  GstDeInterlace *filter;
  GstPad *otherpad;

  filter = GST_DEINTERLACE (gst_pad_get_parent (pad));

  otherpad = (pad == filter->srcpad) ? filter->sinkpad : filter->srcpad;

  return gst_pad_get_allowed_caps (otherpad);
}

static GstPadLinkReturn
gst_deinterlace_link (GstPad * pad, const GstCaps * caps)
{
  GstDeInterlace *filter;
  GstStructure *structure;
  GstPadLinkReturn ret;
  GstPad *otherpad;

  filter = GST_DEINTERLACE (gst_pad_get_parent (pad));

  otherpad = (pad == filter->srcpad) ? filter->sinkpad : filter->srcpad;

  ret = gst_pad_try_set_caps (otherpad, caps);
  if (GST_PAD_LINK_FAILED (ret)) {
    return ret;
  }

  structure = gst_caps_get_structure (caps, 0);
  gst_structure_get_int (structure, "width", &filter->width);
  gst_structure_get_int (structure, "height", &filter->height);

  if (filter->picsize != GST_VIDEO_I420_SIZE (filter->width, filter->height)) {
    if (filter->src)
      g_free (filter->src);
    filter->picsize = GST_VIDEO_I420_SIZE (filter->width, filter->height);
    filter->src = g_malloc (filter->picsize);
  }

  return GST_PAD_LINK_OK;
}

static void
gst_deinterlace_init (GstDeInterlace * filter)
{
  filter->sinkpad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&deinterlace_sink_factory), "sink");
  gst_pad_set_chain_function (filter->sinkpad, gst_deinterlace_chain);
  gst_pad_set_link_function (filter->sinkpad, gst_deinterlace_link);
  gst_pad_set_getcaps_function (filter->sinkpad, gst_deinterlace_getcaps);
  gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);

  filter->srcpad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&deinterlace_src_factory), "src");
  gst_pad_set_link_function (filter->srcpad, gst_deinterlace_link);
  gst_pad_set_getcaps_function (filter->srcpad, gst_deinterlace_getcaps);
  gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);

  filter->show_deinterlaced_area_only = FALSE;
  filter->blend = FALSE;
  /*filter->threshold_blend = 0;  */
  filter->threshold = 50;
  filter->edge_detect = 25;

  filter->src = NULL;
  filter->picsize = 0;
}

static void
gst_deinterlace_chain (GstPad * pad, GstData * _data)
{
  GstBuffer *buf = gst_buffer_copy_on_write (GST_BUFFER (_data));
  GstDeInterlace *filter;
  gint y0, y1, y2, y3;
  guchar *psrc1, *psrc2, *psrc3, *pdst1, *yuvptr, *src;
  gint iInterlaceValue0, iInterlaceValue1, iInterlaceValue2;
  gint x, y;
  gint y_line;
  guchar *y_dst, *y_src;
  gboolean bBlend;
  gint iThreshold;
  gint iEdgeDetect;
  gint width, height;
  gboolean bShowDeinterlacedAreaOnly;

  g_return_if_fail (pad != NULL);
  g_return_if_fail (GST_IS_PAD (pad));
  g_return_if_fail (buf != NULL);

  filter = GST_DEINTERLACE (gst_pad_get_parent (pad));

  bBlend = filter->blend;
  iThreshold = filter->threshold;
  iEdgeDetect = filter->edge_detect;
  width = filter->width;
  height = filter->height;
  src = filter->src;
  yuvptr = GST_BUFFER_DATA (buf);
  bShowDeinterlacedAreaOnly = filter->show_deinterlaced_area_only;

  memcpy (filter->src, yuvptr, filter->picsize);

  y_dst = yuvptr;               /* dst y pointer */
  /* we should not change u,v because one u, v value stands for */
  /* 2 pixels per 2 lines = 4 pixel and we don't want to change */
  /* the color of */

  y_line = GST_VIDEO_I420_Y_ROWSTRIDE (width);
  y_src = src;

  iThreshold = iThreshold * iThreshold * 4;
  /* We don't want an integer overflow in the  interlace calculation. */
  if (iEdgeDetect > 180)
    iEdgeDetect = 180;
  iEdgeDetect = iEdgeDetect * iEdgeDetect;

  y1 = 0;                       /* Avoid compiler warning. The value is not used. */
  for (x = 0; x < width; x++) {
    psrc3 = y_src + x;
    y3 = *psrc3;
    psrc2 = psrc3 + y_line;
    y2 = *psrc2;
    pdst1 = y_dst + x;
    iInterlaceValue1 = iInterlaceValue2 = 0;
    for (y = 0; y <= height; y++) {
      psrc1 = psrc2;
      psrc2 = psrc3;
      psrc3 = psrc3 + y_line;
      y0 = y1;
      y1 = y2;
      y2 = y3;
      if (y < height - 1) {
        y3 = *psrc3;
      } else {
        y3 = y1;
      }

      iInterlaceValue0 = iInterlaceValue1;
      iInterlaceValue1 = iInterlaceValue2;

      if (y < height)
        iInterlaceValue2 = ((y1 - y2) * (y3 - y2) -
            ((iEdgeDetect * (y1 - y3) * (y1 - y3)) >> 12)) * 10;
      else
        iInterlaceValue2 = 0;

      if (y > 0) {
        if (iInterlaceValue0 + 2 * iInterlaceValue1 + iInterlaceValue2 >
            iThreshold) {
          if (bBlend) {
            *pdst1 = (unsigned char) ((y0 + 2 * y1 + y2) >> 2);
          } else {
            /* this method seems to work better than blending if the */
            /* quality is pretty bad and the half pics don't fit together */
            if ((y % 2) == 1) { /* if odd simply copy the value */
              *pdst1 = *psrc1;
              /**pdst1 = 0; // FIXME this is for adjusting an initial iThreshold */
            } else {            /* even interpolate the even line (upper + lower)/2 */
              *pdst1 = (unsigned char) ((y0 + y2) >> 1);
              /**pdst1 = 0; // FIXME this is for adjusting an initial iThreshold */
            }
          }
        } else {
          /* so we went below the treshold and therefore we don't have to  */
          /* change anything */
          if (bShowDeinterlacedAreaOnly) {
            /* this is for testing to see how we should tune the treshhold */
            /* and shows as the things that haven't change because the  */
            /* threshhold was to low?? (or shows that everything is ok :-) */
            *pdst1 = 0;         /* blank the point and so the interlac area */
          } else {
            *pdst1 = *psrc1;
          }
        }
        pdst1 = pdst1 + y_line;
      }
    }
  }

  gst_pad_push (filter->srcpad, GST_DATA (buf));
}

static void
gst_deinterlace_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstDeInterlace *filter;

  g_return_if_fail (GST_IS_DEINTERLACE (object));

  filter = GST_DEINTERLACE (object);

  switch (prop_id) {
    case ARG_DI_ONLY:
      filter->show_deinterlaced_area_only = g_value_get_boolean (value);
      break;
    case ARG_BLEND:
      filter->blend = g_value_get_boolean (value);
      break;
    case ARG_THRESHOLD:
      filter->threshold = g_value_get_int (value);
      break;
    case ARG_EDGE_DETECT:
      filter->edge_detect = g_value_get_int (value);
      break;
    default:
      break;
  }
}

static void
gst_deinterlace_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstDeInterlace *filter;

  g_return_if_fail (GST_IS_DEINTERLACE (object));

  filter = GST_DEINTERLACE (object);

  switch (prop_id) {
    case ARG_DI_ONLY:
      g_value_set_boolean (value, filter->show_deinterlaced_area_only);
      break;
    case ARG_BLEND:
      g_value_set_boolean (value, filter->blend);
      break;
    case ARG_THRESHOLD:
      g_value_set_int (value, filter->threshold);
      break;
    case ARG_EDGE_DETECT:
      g_value_set_int (value, filter->edge_detect);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  if (!gst_element_register (plugin, "deinterlace", GST_RANK_NONE,
          gst_deinterlace_get_type ()))
    return FALSE;

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    "deinterlace",
    "Deinterlace video", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME,
    GST_PACKAGE_ORIGIN);