gstreamer/gst/median/gstmedian.c

/* 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.
 */

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

static GstStaticPadTemplate median_src_factory = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("I420"))
    );

static GstStaticPadTemplate median_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("I420"))
    );


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

enum
{
  PROP_0,
  PROP_ACTIVE,
  PROP_FILTERSIZE,
  PROP_LUM_ONLY
};

#define gst_median_parent_class parent_class
G_DEFINE_TYPE (GstMedian, gst_median, GST_TYPE_VIDEO_FILTER);

static void median_5 (guint8 * src, gint sstride, const guint8 * dest,
    gint dstride, gint width, gint height);
#if 0
static void median_9 (unsigned char *src, unsigned char *dest, int height,
    int width);
#endif

static GstFlowReturn gst_median_transform_frame (GstVideoFilter * filter,
    GstVideoFrame * in_frame, GstVideoFrame * out_frame);

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

static void
gst_median_class_init (GstMedianClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;
  GstVideoFilterClass *vfilter_class;

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

  gobject_class->set_property = gst_median_set_property;
  gobject_class->get_property = gst_median_get_property;

  /* FIXME: add long property descriptions */
  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_ACTIVE,
      g_param_spec_boolean ("active", "active", "active", TRUE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_FILTERSIZE,
      g_param_spec_int ("filtersize", "filtersize", "filtersize", G_MININT,
          G_MAXINT, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_LUM_ONLY,
      g_param_spec_boolean ("lum-only", "lum-only", "lum-only", TRUE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  gst_element_class_add_pad_template (gstelement_class,
      gst_static_pad_template_get (&median_sink_factory));
  gst_element_class_add_pad_template (gstelement_class,
      gst_static_pad_template_get (&median_src_factory));
  gst_element_class_set_static_metadata (gstelement_class, "Median effect",
      "Filter/Effect/Video",
      "Apply a median filter to an image",
      "Wim Taymans <wim.taymans@gmail.com>");

  vfilter_class->transform_frame =
      GST_DEBUG_FUNCPTR (gst_median_transform_frame);
}

void
gst_median_init (GstMedian * median)
{
  median->filtersize = 5;
  median->lum_only = TRUE;
  median->active = TRUE;
}

#define PIX_SORT(a,b) { if ((a)>(b)) PIX_SWAP((a),(b)); }
#define PIX_SWAP(a,b) { unsigned char temp=(a);(a)=(b);(b)=temp; }

static void
median_5 (guint8 * dest, gint dstride, const guint8 * src, gint sstride,
    gint width, gint height)
{
  unsigned char p[5];
  int i, j, k;

  /* copy the top and bottom rows into the result array */
  for (i = 0; i < width; i++) {
    dest[i] = src[i];
    dest[(height - 1) * dstride + i] = src[(height - 1) * sstride + i];
  }

  /* process the interior pixels */
  for (k = 2; k < height; k++) {
    dest += dstride;
    src += sstride;

    dest[0] = src[0];
    for (j = 2, i = 1; j < width; j++, i++) {
      p[0] = src[i - sstride];
      p[1] = src[i - 1];
      p[2] = src[i];
      p[3] = src[i + 1];
      p[4] = src[i + sstride];
      PIX_SORT (p[0], p[1]);
      PIX_SORT (p[3], p[4]);
      PIX_SORT (p[0], p[3]);
      PIX_SORT (p[1], p[4]);
      PIX_SORT (p[1], p[2]);
      PIX_SORT (p[2], p[3]);
      PIX_SORT (p[1], p[2]);
      dest[i] = p[2];
    }
    dest[i] = src[i];
  }
}

static void
median_9 (guint8 * dest, gint dstride, const guint8 * src, gint sstride,
    gint width, gint height)
{
  unsigned char p[9];
  int i, j, k;

  /*copy the top and bottom rows into the result array */
  for (i = 0; i < width; i++) {
    dest[i] = src[i];
    dest[(height - 1) * dstride + i] = src[(height - 1) * sstride + i];
  }
  /* process the interior pixels */
  for (k = 2; k < height; k++) {
    dest += dstride;
    src += sstride;

    dest[0] = src[0];
    for (j = 2, i = 1; j < width; j++, i++) {
      p[0] = src[i - sstride - 1];
      p[1] = src[i - sstride];
      p[2] = src[i - sstride + 1];
      p[3] = src[i - 1];
      p[4] = src[i];
      p[5] = src[i + 1];
      p[6] = src[i + sstride - 1];
      p[7] = src[i + sstride];
      p[8] = src[i + sstride + 1];
      PIX_SORT (p[1], p[2]);
      PIX_SORT (p[4], p[5]);
      PIX_SORT (p[7], p[8]);
      PIX_SORT (p[0], p[1]);
      PIX_SORT (p[3], p[4]);
      PIX_SORT (p[6], p[7]);
      PIX_SORT (p[1], p[2]);
      PIX_SORT (p[4], p[5]);
      PIX_SORT (p[7], p[8]);
      PIX_SORT (p[0], p[3]);
      PIX_SORT (p[5], p[8]);
      PIX_SORT (p[4], p[7]);
      PIX_SORT (p[3], p[6]);
      PIX_SORT (p[1], p[4]);
      PIX_SORT (p[2], p[5]);
      PIX_SORT (p[4], p[7]);
      PIX_SORT (p[4], p[2]);
      PIX_SORT (p[6], p[4]);
      PIX_SORT (p[4], p[2]);
      dest[i] = p[4];
    }
    dest[i] = src[i];
  }
}

static GstFlowReturn
gst_median_transform_frame (GstVideoFilter * filter, GstVideoFrame * in_frame,
    GstVideoFrame * out_frame)
{
  GstMedian *median = GST_MEDIAN (filter);

  if (median->filtersize == 5) {
    median_5 (GST_VIDEO_FRAME_PLANE_DATA (out_frame, 0),
        GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 0),
        GST_VIDEO_FRAME_PLANE_DATA (in_frame, 0),
        GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 0),
        GST_VIDEO_FRAME_WIDTH (in_frame), GST_VIDEO_FRAME_HEIGHT (in_frame));

    if (median->lum_only) {
      gst_video_frame_copy_plane (out_frame, in_frame, 1);
      gst_video_frame_copy_plane (out_frame, in_frame, 2);
    } else {
      median_5 (GST_VIDEO_FRAME_PLANE_DATA (out_frame, 1),
          GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 1),
          GST_VIDEO_FRAME_PLANE_DATA (in_frame, 1),
          GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 1),
          GST_VIDEO_FRAME_WIDTH (in_frame) / 2,
          GST_VIDEO_FRAME_HEIGHT (in_frame) / 2);
      median_5 (GST_VIDEO_FRAME_PLANE_DATA (out_frame, 2),
          GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 2),
          GST_VIDEO_FRAME_PLANE_DATA (in_frame, 2),
          GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 2),
          GST_VIDEO_FRAME_WIDTH (in_frame) / 2,
          GST_VIDEO_FRAME_HEIGHT (in_frame) / 2);
    }
  } else {
    median_9 (GST_VIDEO_FRAME_PLANE_DATA (out_frame, 0),
        GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 0),
        GST_VIDEO_FRAME_PLANE_DATA (in_frame, 0),
        GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 0),
        GST_VIDEO_FRAME_WIDTH (in_frame), GST_VIDEO_FRAME_HEIGHT (in_frame));

    if (median->lum_only) {
      gst_video_frame_copy_plane (out_frame, in_frame, 1);
      gst_video_frame_copy_plane (out_frame, in_frame, 2);
    } else {
      median_9 (GST_VIDEO_FRAME_PLANE_DATA (out_frame, 1),
          GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 1),
          GST_VIDEO_FRAME_PLANE_DATA (in_frame, 1),
          GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 1),
          GST_VIDEO_FRAME_WIDTH (in_frame) / 2,
          GST_VIDEO_FRAME_HEIGHT (in_frame) / 2);
      median_9 (GST_VIDEO_FRAME_PLANE_DATA (out_frame, 2),
          GST_VIDEO_FRAME_PLANE_STRIDE (out_frame, 2),
          GST_VIDEO_FRAME_PLANE_DATA (in_frame, 2),
          GST_VIDEO_FRAME_PLANE_STRIDE (in_frame, 2),
          GST_VIDEO_FRAME_WIDTH (in_frame) / 2,
          GST_VIDEO_FRAME_HEIGHT (in_frame) / 2);
    }
  }

  return GST_FLOW_OK;
}

static void
gst_median_set_property (GObject * object, guint prop_id, const GValue * value,
    GParamSpec * pspec)
{
  GstMedian *median;
  gint argvalue;

  g_return_if_fail (GST_IS_MEDIAN (object));
  median = GST_MEDIAN (object);

  switch (prop_id) {
    case PROP_FILTERSIZE:
      argvalue = g_value_get_int (value);
      if (argvalue != 5 && argvalue != 9) {
        g_warning ("median: invalid filtersize (%d), must be 5 or 9\n",
            argvalue);
      } else {
        median->filtersize = argvalue;
      }
      break;
    case PROP_ACTIVE:
      median->active = g_value_get_boolean (value);
      break;
    case PROP_LUM_ONLY:
      median->lum_only = g_value_get_boolean (value);
      break;
    default:
      break;
  }
}

static void
gst_median_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstMedian *median;

  g_return_if_fail (GST_IS_MEDIAN (object));
  median = GST_MEDIAN (object);

  switch (prop_id) {
    case PROP_FILTERSIZE:
      g_value_set_int (value, median->filtersize);
      break;
    case PROP_ACTIVE:
      g_value_set_boolean (value, median->active);
      break;
    case PROP_LUM_ONLY:
      g_value_set_boolean (value, median->lum_only);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}


static gboolean
plugin_init (GstPlugin * plugin)
{
  return gst_element_register (plugin, "median",
      GST_RANK_NONE, GST_TYPE_MEDIAN);
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    median,
    "Video median filter",
    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)