[gst-devel] [PATCH] new videofilter: gamma correction

Arwed von Merkatz a.v.merkatz at t-online.de
Sat Jan 10 10:31:02 CET 2004


Hi,

due to a very old monitor i need gamma correction to see anything when
playing video. gst was missing such a filter, so i wrote a simple one.

-- 
Arwed v. Merkatz
Grimoire Guru for video
Grimoire Guru for xfce
Sourcemage GNU/Linux
http://www.sourcemage.org
-------------- next part --------------
diff -Nur -x CVS gst-plugins/gst/videofilter/gstvideogamma.c gst-plugins-gamma/gst/videofilter/gstvideogamma.c
--- gst-plugins/gst/videofilter/gstvideogamma.c	1970-01-01 01:00:00.000000000 +0100
+++ gst-plugins-gamma/gst/videofilter/gstvideogamma.c	2004-01-10 19:25:26.000000000 +0100
@@ -0,0 +1,249 @@
+/* GStreamer
+ * (c) 2003 Arwed v. Merkatz <v.merkatz at gmx.net>
+ *
+ * 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.
+ */
+
+/*
+ * This file was (probably) generated from gstvideotemplate.c,
+ * gstvideotemplate.c,v 1.9 2003/12/04 10:37:28 wingo Exp 
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/*#define DEBUG_ENABLED */
+#include <gstvideogamma.h>
+#include <string.h>
+#include <math.h>
+
+/* Gstvideogamma signals and args */
+enum {
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum {
+  ARG_0,
+  ARG_GAMMA,
+  /* FILL ME */
+};
+
+static void	gst_videogamma_base_init	(gpointer g_class);
+static void	gst_videogamma_class_init	(gpointer g_class, gpointer class_data);
+static void	gst_videogamma_init		(GTypeInstance *instance, gpointer g_class);
+
+static void	gst_videogamma_set_property		(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
+static void	gst_videogamma_get_property		(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
+
+static void gst_videogamma_planar411(GstVideofilter *videofilter, void *dest, void *src);
+static void gst_videogamma_setup(GstVideofilter *videofilter);
+
+GType
+gst_videogamma_get_type (void)
+{
+  static GType videogamma_type = 0;
+
+  if (!videogamma_type) {
+    static const GTypeInfo videogamma_info = {
+      sizeof(GstvideogammaClass),
+      gst_videogamma_base_init,
+      NULL,
+      gst_videogamma_class_init,
+      NULL,
+      NULL,
+      sizeof(Gstvideogamma),
+      0,
+      gst_videogamma_init,
+    };
+    videogamma_type = g_type_register_static(GST_TYPE_VIDEOFILTER,
+        "Gstvideogamma", &videogamma_info, 0);
+  }
+  return videogamma_type;
+}
+
+static GstVideofilterFormat gst_videogamma_formats[] = {
+  { "I420", 12, gst_videogamma_planar411, },
+};
+
+  
+static void
+gst_videogamma_base_init (gpointer g_class)
+{
+  static GstElementDetails videogamma_details = GST_ELEMENT_DETAILS (
+    "Video Gamma Correction",
+    "Filter/Effect/Video",
+    "Adjusts gamma on a video stream",
+    "Arwed v. Merkatz <v.merkatz at gmx.net"
+  );
+  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, &videogamma_details);
+
+  for(i=0;i<G_N_ELEMENTS(gst_videogamma_formats);i++){
+    gst_videofilter_class_add_format(videofilter_class,
+	gst_videogamma_formats + i);
+  }
+
+  gst_videofilter_class_add_pad_templates (GST_VIDEOFILTER_CLASS (g_class));
+}
+
+static void
+gst_videogamma_class_init (gpointer g_class, gpointer class_data)
+{
+  GObjectClass *gobject_class;
+  GstVideofilterClass *videofilter_class;
+
+  gobject_class = G_OBJECT_CLASS (g_class);
+  videofilter_class = GST_VIDEOFILTER_CLASS (g_class);
+
+  g_object_class_install_property(gobject_class, ARG_GAMMA,
+      g_param_spec_double("gamma", "Gamma", "gamma",
+      0.01, 10, 1, G_PARAM_READWRITE));
+
+  gobject_class->set_property = gst_videogamma_set_property;
+  gobject_class->get_property = gst_videogamma_get_property;
+
+  videofilter_class->setup = gst_videogamma_setup;
+}
+
+static void
+gst_videogamma_init (GTypeInstance *instance, gpointer g_class)
+{
+  Gstvideogamma *videogamma = GST_VIDEOGAMMA (instance);
+  GstVideofilter *videofilter;
+
+  GST_DEBUG("gst_videogamma_init");
+
+  videofilter = GST_VIDEOFILTER(videogamma);
+
+  /* do stuff */
+  videogamma->gamma = 1;
+  videogamma->gamma_table_calculated = 0;
+}
+
+static void
+gst_videogamma_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
+{
+  Gstvideogamma *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail(GST_IS_VIDEOGAMMA(object));
+  src = GST_VIDEOGAMMA(object);
+
+  GST_DEBUG("gst_videogamma_set_property");
+  switch (prop_id) {
+    case ARG_GAMMA:
+      src->gamma = 1.0 / g_value_get_double (value);
+      src->gamma_table_calculated = 0;
+      break;
+    default:
+      break;
+  }
+}
+
+static void
+gst_videogamma_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
+{
+  Gstvideogamma *src;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail(GST_IS_VIDEOGAMMA(object));
+  src = GST_VIDEOGAMMA(object);
+
+  switch (prop_id) {
+    case ARG_GAMMA:
+      g_value_set_double (value, 1.0 / src->gamma);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static gboolean plugin_init (GstPlugin *plugin)
+{
+  if(!gst_library_load("gstvideofilter"))
+    return FALSE;
+
+  return gst_element_register (plugin, "videogamma", GST_RANK_NONE,
+      GST_TYPE_VIDEOGAMMA);
+}
+
+GST_PLUGIN_DEFINE (
+  GST_VERSION_MAJOR,
+  GST_VERSION_MINOR,
+  "videogamma",
+  "Changes gamma on video images",
+  plugin_init,
+  VERSION,
+  GST_LICENSE,
+  GST_PACKAGE,
+  GST_ORIGIN
+)
+
+static void gst_videogamma_setup(GstVideofilter *videofilter)
+{
+  Gstvideogamma *videogamma;
+
+  g_return_if_fail(GST_IS_VIDEOGAMMA(videofilter));
+  videogamma = GST_VIDEOGAMMA(videofilter);
+
+  /* if any setup needs to be done, do it here */
+
+}
+
+static void gst_videogamma_planar411(GstVideofilter *videofilter,
+    void *dest, void *src)
+{
+  Gstvideogamma *videogamma;
+  int width = gst_videofilter_get_input_width(videofilter);
+  int height = gst_videofilter_get_input_height(videofilter);
+  int n;
+  double val;
+
+  g_return_if_fail(GST_IS_VIDEOGAMMA(videofilter));
+  videogamma = GST_VIDEOGAMMA(videofilter);
+
+  memcpy(dest,src,width * height + (width/2) * (height/2) * 2);
+
+  if (videogamma->gamma != 1.0) {
+    if (!videogamma->gamma_table_calculated) {
+      for (n = 0; n < 256; n++) {
+        val = n/255.0;
+        val = pow(val, videogamma->gamma);
+        val = 255.0 * val;
+        videogamma->gamma_table[n] = (unsigned char) val;
+      }
+      videogamma->gamma_table_calculated = 1;
+    }
+    
+    {
+      guint8 *cdest = dest;
+      guint8 *csrc = src;
+      int x,y;
+      for (y=0; y < height; y++) {
+        for (x=0; x < width; x++) {
+          cdest[y*width + x] = videogamma->gamma_table[(unsigned char)csrc[y*width + x]];
+        }
+      }
+    }
+  }
+}
+
diff -Nur -x CVS gst-plugins/gst/videofilter/gstvideogamma.h gst-plugins-gamma/gst/videofilter/gstvideogamma.h
--- gst-plugins/gst/videofilter/gstvideogamma.h	1970-01-01 01:00:00.000000000 +0100
+++ gst-plugins-gamma/gst/videofilter/gstvideogamma.h	2004-01-10 19:24:11.000000000 +0100
@@ -0,0 +1,63 @@
+/* GStreamer
+ * (c) 2003 Arwed v. Merkatz <v.merkatz at gmx.net>
+ *
+ * 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.
+ */
+
+
+#ifndef __GST_VIDEOGAMMA_H__
+#define __GST_VIDEOGAMMA_H__
+
+
+#include <gst/gst.h>
+
+#include "gstvideofilter.h"
+
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_VIDEOGAMMA \
+  (gst_videogamma_get_type())
+#define GST_VIDEOGAMMA(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEOGAMMA,Gstvideogamma))
+#define GST_VIDEOGAMMA_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEOGAMMA,GstvideogammaClass))
+#define GST_IS_VIDEOGAMMA(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEOGAMMA))
+#define GST_IS_VIDEOGAMMA_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEOGAMMA))
+
+typedef struct _Gstvideogamma Gstvideogamma;
+typedef struct _GstvideogammaClass GstvideogammaClass;
+
+struct _Gstvideogamma {
+  GstVideofilter videofilter;
+
+  double gamma;
+  int gamma_table_calculated;
+  unsigned char gamma_table[256];
+};
+
+struct _GstvideogammaClass {
+  GstVideofilterClass parent_class;
+};
+
+GType gst_videogamma_get_type(void);
+
+G_END_DECLS
+
+#endif /* __GST_VIDEOGAMMA_H__ */
+
diff -Nur -x CVS gst-plugins/gst/videofilter/Makefile.am gst-plugins-gamma/gst/videofilter/Makefile.am
--- gst-plugins/gst/videofilter/Makefile.am	2004-01-10 19:18:31.000000000 +0100
+++ gst-plugins-gamma/gst/videofilter/Makefile.am	2004-01-10 19:17:42.000000000 +0100
@@ -1,9 +1,9 @@
 
 plugin_LTLIBRARIES = libgstvideofilter.la libgstvideoflip.la \
-	libgstvideobalance.la
+	libgstvideobalance.la libgstvideogamma.la
 noinst_LTLIBRARIES = libgstvideoexample.la
 
-noinst_HEADERS = gstvideofilter.h gstvideoflip.h gstvideobalance.h
+noinst_HEADERS = gstvideofilter.h gstvideoflip.h gstvideobalance.h gstvideogamma.h
 
 EXTRA_DIST = gstvideotemplate.c make_filter
 CLEANFILES = gstvideoexample.c
@@ -28,6 +28,10 @@
 libgstvideobalance_la_LIBADD =
 libgstvideobalance_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS) -lm
 
+libgstvideogamma_la_SOURCES = gstvideogamma.c
+libgstvideogamma_la_CFLAGS = $(GST_CFLAGS)
+libgstvideogamma_la_LIBADD =
+libgstvideogamma_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS) -lm
 
 gstvideoexample.c: $(srcdir)/make_filter $(srcdir)/gstvideotemplate.c
 	$(srcdir)/make_filter Videoexample $(srcdir)/gstvideotemplate.c


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