gstreamer/gst/effectv/gstrev.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * EffecTV:
 * Copyright (C) 2001 FUKUCHI Kentarou
 *
 * EffecTV - Realtime Digital Video Effector
 * Copyright (C) 2001 FUKUCHI Kentarou
 *
 * revTV based on Rutt-Etra Video Synthesizer 1974?

 * (c)2002 Ed Tannenbaum
 *
 * This effect acts like a waveform monitor on each line.
 * It was originally done by deflecting the electron beam on a monitor using
 * additional electromagnets on the yoke of a b/w CRT. 
 * Here it is emulated digitally.

 * Experimaental tapes were made with this system by Bill and 
 * Louise Etra and Woody and Steina Vasulka

 * The line spacing can be controlled using the 1 and 2 Keys.
 * The gain is controlled using the 3 and 4 keys.
 * The update rate is controlled using the 0 and - keys.
 
 * EffecTV is free software. 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 <math.h>
#include <string.h>
#include <gst/gst.h>
#include <gstvideofilter.h>

#define GST_TYPE_REVTV \
  (gst_revtv_get_type())
#define GST_REVTV(obj) \
  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_REVTV,GstRevTV))
#define GST_REVTV_CLASS(klass) \
  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_REVTV,GstRevTVClass))
#define GST_IS_REVTV(obj) \
  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_REVTV))
#define GST_IS_REVTV_CLASS(obj) \
  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_REVTV))

#define THE_COLOR 0xffffffff

typedef struct _GstRevTV GstRevTV;
typedef struct _GstRevTVClass GstRevTVClass;

struct _GstRevTV
{
  GstVideofilter videofilter;

  gint width, height;
  gint vgrabtime;
  gint vgrab;
  gint linespace;
  gint vscale;
};

struct _GstRevTVClass
{
  GstVideofilterClass parent_class;

  void (*reset) (GstElement * element);
};

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

enum
{
  ARG_0,
  ARG_DELAY,
  ARG_LINESPACE,
  ARG_GAIN
};

static void gst_revtv_base_init (gpointer g_class);
static void gst_revtv_class_init (gpointer g_class, gpointer class_data);
static void gst_revtv_init (GTypeInstance * instance, gpointer g_class);

static void gst_revtv_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_revtv_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static void gst_revtv_setup (GstVideofilter * videofilter);
static void gst_revtv_rgb32 (GstVideofilter * videofilter, void *d, void *s);

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

GType
gst_revtv_get_type (void)
{
  static GType revtv_type = 0;

  if (!revtv_type) {
    static const GTypeInfo revtv_info = {
      sizeof (GstRevTVClass),
      gst_revtv_base_init,
      NULL,
      (GClassInitFunc) gst_revtv_class_init,
      NULL,
      NULL,
      sizeof (GstRevTV),
      0,
      (GInstanceInitFunc) gst_revtv_init,
    };

    revtv_type =
        g_type_register_static (GST_TYPE_VIDEOFILTER, "GstRevTV", &revtv_info,
        0);
  }
  return revtv_type;
}

static GstVideofilterFormat gst_revtv_formats[] = {
  {"RGB ", 32, gst_revtv_rgb32, 24, G_BIG_ENDIAN, 0x0000ff00, 0x00ff0000,
      0xff000000}
};

static void
gst_revtv_base_init (gpointer g_class)
{
  /* elementfactory information */
  static GstElementDetails gst_revtv_details = GST_ELEMENT_DETAILS ("RevTV",
      "Filter/Effect/Video",
      "A video waveform monitor for each line of video processed",
      "Wim Taymans <wim.taymans@chello.be>");

  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
  GstVideofilterClass *videofilter_class = GST_VIDEOFILTER_CLASS (g_class);
  int i;

  gst_element_class_set_details (element_class, &gst_revtv_details);

  for (i = 0; i < G_N_ELEMENTS (gst_revtv_formats); i++) {
    gst_videofilter_class_add_format (videofilter_class, gst_revtv_formats + i);
  }

  gst_videofilter_class_add_pad_templates (GST_VIDEOFILTER_CLASS (g_class));
}

static void
gst_revtv_class_init (gpointer klass, gpointer class_data)
{
  GObjectClass *gobject_class;
  GstVideofilterClass *videofilter_class;

  gobject_class = G_OBJECT_CLASS (klass);
  videofilter_class = GST_VIDEOFILTER_CLASS (klass);

  gobject_class->set_property = gst_revtv_set_property;
  gobject_class->get_property = gst_revtv_get_property;

  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_DELAY,
      g_param_spec_int ("delay", "Delay", "Delay in frames between updates",
          1, 100, 1, G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_LINESPACE,
      g_param_spec_int ("linespace", "Linespace", "Control line spacing",
          1, 100, 6, G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_GAIN,
      g_param_spec_int ("gain", "Gain", "Control gain",
          1, 200, 50, G_PARAM_READWRITE));

  videofilter_class->setup = gst_revtv_setup;
}

static void
gst_revtv_init (GTypeInstance * instance, gpointer g_class)
{
  GstRevTV *restv = GST_REVTV (instance);

  restv->vgrabtime = 1;
  restv->vgrab = 0;
  restv->linespace = 6;
  restv->vscale = 50;
}

static void
gst_revtv_setup (GstVideofilter * videofilter)
{
  GstRevTV *revtv;

  g_return_if_fail (GST_IS_REVTV (videofilter));
  revtv = GST_REVTV (videofilter);

  revtv->width = gst_videofilter_get_input_width (videofilter);
  revtv->height = gst_videofilter_get_input_height (videofilter);
}

static void
gst_revtv_rgb32 (GstVideofilter * videofilter, void *d, void *s)
{
  GstRevTV *filter;
  guint32 *src, *dest;
  gint width, height;
  guint32 *nsrc;
  gint y, x, R, G, B, yval;

  filter = GST_REVTV (videofilter);

  src = (guint32 *) s;
  dest = (guint32 *) d;

  width = filter->width;
  height = filter->height;

  /* Clear everything to black */
  memset (dest, 0, width * height * sizeof (guint32));

  // draw the offset lines
  for (y = 0; y < height; y += filter->linespace) {
    for (x = 0; x <= width; x++) {
      nsrc = src + (y * width) + x;

      // Calc Y Value for curpix
      R = ((*nsrc) & 0xff0000) >> (16 - 1);
      G = ((*nsrc) & 0xff00) >> (8 - 2);
      B = (*nsrc) & 0xff;

      yval = y - ((short) (R + G + B) / filter->vscale);

      if (yval > 0) {
        dest[x + (yval * width)] = THE_COLOR;
      }
    }
  }
}

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

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail (GST_IS_REVTV (object));

  filter = GST_REVTV (object);

  switch (prop_id) {
    case ARG_DELAY:
      filter->vgrabtime = g_value_get_int (value);
      break;
    case ARG_LINESPACE:
      filter->linespace = g_value_get_int (value);
      break;
    case ARG_GAIN:
      filter->vscale = g_value_get_int (value);
      break;
    default:
      break;
  }
}

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

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail (GST_IS_REVTV (object));

  filter = GST_REVTV (object);

  switch (prop_id) {
    case ARG_DELAY:
      g_value_set_int (value, filter->vgrabtime);
      break;
    case ARG_LINESPACE:
      g_value_set_int (value, filter->linespace);
      break;
    case ARG_GAIN:
      g_value_set_int (value, filter->vscale);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}