--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_good/gst/alpha/gstalpha.c Fri Apr 16 15:15:52 2010 +0300
@@ -0,0 +1,930 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ * Copyright (C) <2007> Wim Taymans <wim.taymans@collabora.co.uk>
+ * Copyright (C) <2007> Edward Hervey <edward.hervey@collabora.co.uk>
+ * Copyright (C) <2007> Jan Schmidt <thaytan@noraisin.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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <gst/gst.h>
+#include <gst/base/gstbasetransform.h>
+#include <gst/video/video.h>
+#include <gst/controller/gstcontroller.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+#define GST_TYPE_ALPHA \
+ (gst_alpha_get_type())
+#define GST_ALPHA(obj) \
+ (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_ALPHA,GstAlpha))
+#define GST_ALPHA_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ALPHA,GstAlphaClass))
+#define GST_IS_ALPHA(obj) \
+ (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ALPHA))
+#define GST_IS_ALPHA_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ALPHA))
+
+typedef struct _GstAlpha GstAlpha;
+typedef struct _GstAlphaClass GstAlphaClass;
+
+typedef enum
+{
+ ALPHA_METHOD_SET,
+ ALPHA_METHOD_GREEN,
+ ALPHA_METHOD_BLUE,
+ ALPHA_METHOD_CUSTOM,
+}
+GstAlphaMethod;
+
+GST_DEBUG_CATEGORY_STATIC (gst_alpha_debug);
+#define GST_CAT_DEFAULT gst_alpha_debug
+
+struct _GstAlpha
+{
+ GstBaseTransform parent;
+
+ /* caps */
+ GstVideoFormat format;
+ gint width, height;
+ gboolean ayuv;
+
+ gdouble alpha;
+
+ guint target_r;
+ guint target_g;
+ guint target_b;
+
+ GstAlphaMethod method;
+
+ gfloat angle;
+ gfloat noise_level;
+ guint black_sensitivity;
+ guint white_sensitivity;
+
+ gfloat y; /* chroma color */
+ gint8 cb, cr;
+ gint8 kg;
+ gfloat accept_angle_cos;
+ gfloat accept_angle_sin;
+ guint8 accept_angle_tg;
+ guint8 accept_angle_ctg;
+ guint8 one_over_kc;
+ guint8 kfgy_scale;
+};
+
+struct _GstAlphaClass
+{
+ GstBaseTransformClass parent_class;
+};
+
+/* elementfactory information */
+static const GstElementDetails gst_alpha_details =
+GST_ELEMENT_DETAILS ("Alpha filter",
+ "Filter/Effect/Video",
+ "Adds an alpha channel to video - uniform or via chroma-keying",
+ "Wim Taymans <wim@fluendo.com>\n"
+ "Edward Hervey <edward.hervey@collabora.co.uk>\n"
+ "Jan Schmidt <thaytan@noraisin.net>");
+
+/* Alpha signals and args */
+enum
+{
+ /* FILL ME */
+ LAST_SIGNAL
+};
+
+#define DEFAULT_METHOD ALPHA_METHOD_SET
+#define DEFAULT_ALPHA 1.0
+#define DEFAULT_TARGET_R 0
+#define DEFAULT_TARGET_G 255
+#define DEFAULT_TARGET_B 0
+#define DEFAULT_ANGLE 20.0
+#define DEFAULT_NOISE_LEVEL 2.0
+#define DEFAULT_BLACK_SENSITIVITY 100
+#define DEFAULT_WHITE_SENSITIVITY 100
+
+enum
+{
+ PROP_0,
+ PROP_METHOD,
+ PROP_ALPHA,
+ PROP_TARGET_R,
+ PROP_TARGET_G,
+ PROP_TARGET_B,
+ PROP_ANGLE,
+ PROP_NOISE_LEVEL,
+ PROP_BLACK_SENSITIVITY,
+ PROP_WHITE_SENSITIVITY,
+ PROP_LAST
+};
+
+static GstStaticPadTemplate gst_alpha_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV"))
+ );
+
+static GstStaticPadTemplate gst_alpha_sink_template =
+ GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV") ";" GST_VIDEO_CAPS_YUV ("I420")
+ )
+ );
+
+static gboolean gst_alpha_start (GstBaseTransform * trans);
+static gboolean gst_alpha_get_unit_size (GstBaseTransform * btrans,
+ GstCaps * caps, guint * size);
+static GstCaps *gst_alpha_transform_caps (GstBaseTransform * btrans,
+ GstPadDirection direction, GstCaps * caps);
+static gboolean gst_alpha_set_caps (GstBaseTransform * btrans,
+ GstCaps * incaps, GstCaps * outcaps);
+static GstFlowReturn gst_alpha_transform (GstBaseTransform * btrans,
+ GstBuffer * in, GstBuffer * out);
+
+static void gst_alpha_init_params (GstAlpha * alpha);
+
+static void gst_alpha_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec);
+static void gst_alpha_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec);
+
+GST_BOILERPLATE (GstAlpha, gst_alpha, GstBaseTransform,
+ GST_TYPE_BASE_TRANSFORM);
+
+#define GST_TYPE_ALPHA_METHOD (gst_alpha_method_get_type())
+static GType
+gst_alpha_method_get_type (void)
+{
+ static GType alpha_method_type = 0;
+ static const GEnumValue alpha_method[] = {
+ {ALPHA_METHOD_SET, "Set/adjust alpha channel", "set"},
+ {ALPHA_METHOD_GREEN, "Chroma Key green", "green"},
+ {ALPHA_METHOD_BLUE, "Chroma Key blue", "blue"},
+ {ALPHA_METHOD_CUSTOM, "Chroma Key on target_r/g/b", "custom"},
+ {0, NULL, NULL},
+ };
+
+ if (!alpha_method_type) {
+ alpha_method_type = g_enum_register_static ("GstAlphaMethod", alpha_method);
+ }
+ return alpha_method_type;
+}
+
+static void
+gst_alpha_base_init (gpointer g_class)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+ gst_element_class_set_details (element_class, &gst_alpha_details);
+
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&gst_alpha_sink_template));
+ gst_element_class_add_pad_template (element_class,
+ gst_static_pad_template_get (&gst_alpha_src_template));
+
+ GST_DEBUG_CATEGORY_INIT (gst_alpha_debug, "alpha", 0,
+ "alpha - Element for adding alpha channel to streams");
+}
+static void
+gst_alpha_class_init (GstAlphaClass * klass)
+{
+ GObjectClass *gobject_class;
+ GstBaseTransformClass *btrans_class;
+
+ gobject_class = (GObjectClass *) klass;
+ btrans_class = (GstBaseTransformClass *) klass;
+
+ gobject_class->set_property = gst_alpha_set_property;
+ gobject_class->get_property = gst_alpha_get_property;
+
+ g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_METHOD,
+ g_param_spec_enum ("method", "Method",
+ "How the alpha channels should be created", GST_TYPE_ALPHA_METHOD,
+ DEFAULT_METHOD, (GParamFlags) G_PARAM_READWRITE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_ALPHA,
+ g_param_spec_double ("alpha", "Alpha", "The value for the alpha channel",
+ 0.0, 1.0, DEFAULT_ALPHA,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TARGET_R,
+ g_param_spec_uint ("target_r", "Target Red", "The Red target", 0, 255,
+ DEFAULT_TARGET_R,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TARGET_G,
+ g_param_spec_uint ("target_g", "Target Green", "The Green target", 0, 255,
+ DEFAULT_TARGET_G,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TARGET_B,
+ g_param_spec_uint ("target_b", "Target Blue", "The Blue target", 0, 255,
+ DEFAULT_TARGET_B,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_ANGLE,
+ g_param_spec_float ("angle", "Angle", "Size of the colorcube to change",
+ 0.0, 90.0, DEFAULT_ANGLE,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_NOISE_LEVEL,
+ g_param_spec_float ("noise_level", "Noise Level", "Size of noise radius",
+ 0.0, 64.0, DEFAULT_NOISE_LEVEL,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass),
+ PROP_BLACK_SENSITIVITY, g_param_spec_uint ("black-sensitivity",
+ "Black Sensitivity", "Sensitivity to dark colors", 0, 128,
+ DEFAULT_BLACK_SENSITIVITY,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+ g_object_class_install_property (G_OBJECT_CLASS (klass),
+ PROP_WHITE_SENSITIVITY, g_param_spec_uint ("white-sensitivity",
+ "Sensitivity", "Sensitivity to bright colors", 0, 128,
+ DEFAULT_WHITE_SENSITIVITY,
+ (GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
+
+
+ btrans_class->start = GST_DEBUG_FUNCPTR (gst_alpha_start);
+ btrans_class->transform = GST_DEBUG_FUNCPTR (gst_alpha_transform);
+ btrans_class->get_unit_size = GST_DEBUG_FUNCPTR (gst_alpha_get_unit_size);
+ btrans_class->transform_caps = GST_DEBUG_FUNCPTR (gst_alpha_transform_caps);
+ btrans_class->set_caps = GST_DEBUG_FUNCPTR (gst_alpha_set_caps);
+}
+
+static void
+gst_alpha_init (GstAlpha * alpha, GstAlphaClass * klass)
+{
+ alpha->alpha = DEFAULT_ALPHA;
+ alpha->method = DEFAULT_METHOD;
+ alpha->target_r = DEFAULT_TARGET_R;
+ alpha->target_g = DEFAULT_TARGET_G;
+ alpha->target_b = DEFAULT_TARGET_B;
+ alpha->angle = DEFAULT_ANGLE;
+ alpha->noise_level = DEFAULT_NOISE_LEVEL;
+ alpha->black_sensitivity = DEFAULT_BLACK_SENSITIVITY;
+ alpha->white_sensitivity = DEFAULT_WHITE_SENSITIVITY;
+}
+
+/* do we need this function? */
+static void
+gst_alpha_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec)
+{
+ GstAlpha *alpha;
+
+ g_return_if_fail (GST_IS_ALPHA (object));
+
+ alpha = GST_ALPHA (object);
+
+ switch (prop_id) {
+ case PROP_METHOD:
+ alpha->method = g_value_get_enum (value);
+ switch (alpha->method) {
+ case ALPHA_METHOD_GREEN:
+ alpha->target_r = 0;
+ alpha->target_g = 255;
+ alpha->target_b = 0;
+ break;
+ case ALPHA_METHOD_BLUE:
+ alpha->target_r = 0;
+ alpha->target_g = 0;
+ alpha->target_b = 255;
+ break;
+ default:
+ break;
+ }
+ gst_alpha_init_params (alpha);
+ break;
+ case PROP_ALPHA:
+ alpha->alpha = g_value_get_double (value);
+ break;
+ case PROP_TARGET_R:
+ alpha->target_r = g_value_get_uint (value);
+ gst_alpha_init_params (alpha);
+ break;
+ case PROP_TARGET_G:
+ alpha->target_g = g_value_get_uint (value);
+ gst_alpha_init_params (alpha);
+ break;
+ case PROP_TARGET_B:
+ alpha->target_b = g_value_get_uint (value);
+ gst_alpha_init_params (alpha);
+ break;
+ case PROP_ANGLE:
+ alpha->angle = g_value_get_float (value);
+ gst_alpha_init_params (alpha);
+ break;
+ case PROP_NOISE_LEVEL:
+ alpha->noise_level = g_value_get_float (value);
+ gst_alpha_init_params (alpha);
+ break;
+ case PROP_BLACK_SENSITIVITY:
+ alpha->black_sensitivity = g_value_get_uint (value);
+ break;
+ case PROP_WHITE_SENSITIVITY:
+ alpha->white_sensitivity = g_value_get_uint (value);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+static void
+gst_alpha_get_property (GObject * object, guint prop_id, GValue * value,
+ GParamSpec * pspec)
+{
+ GstAlpha *alpha;
+
+ g_return_if_fail (GST_IS_ALPHA (object));
+
+ alpha = GST_ALPHA (object);
+
+ switch (prop_id) {
+ case PROP_METHOD:
+ g_value_set_enum (value, alpha->method);
+ break;
+ case PROP_ALPHA:
+ g_value_set_double (value, alpha->alpha);
+ break;
+ case PROP_TARGET_R:
+ g_value_set_uint (value, alpha->target_r);
+ break;
+ case PROP_TARGET_G:
+ g_value_set_uint (value, alpha->target_g);
+ break;
+ case PROP_TARGET_B:
+ g_value_set_uint (value, alpha->target_b);
+ break;
+ case PROP_ANGLE:
+ g_value_set_float (value, alpha->angle);
+ break;
+ case PROP_NOISE_LEVEL:
+ g_value_set_float (value, alpha->noise_level);
+ break;
+ case PROP_BLACK_SENSITIVITY:
+ g_value_set_uint (value, alpha->black_sensitivity);
+ break;
+ case PROP_WHITE_SENSITIVITY:
+ g_value_set_uint (value, alpha->white_sensitivity);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
+static gboolean
+gst_alpha_get_unit_size (GstBaseTransform * btrans,
+ GstCaps * caps, guint * size)
+{
+ GstVideoFormat format;
+ gint width, height;
+
+ if (!gst_video_format_parse_caps (caps, &format, &width, &height))
+ return FALSE;
+
+ *size = gst_video_format_get_size (format, width, height);
+
+ GST_DEBUG_OBJECT (btrans, "unit size = %d for format %d w %d height %d",
+ *size, format, width, height);
+
+ return TRUE;
+}
+
+static GstCaps *
+gst_alpha_transform_caps (GstBaseTransform * btrans,
+ GstPadDirection direction, GstCaps * caps)
+{
+ GstCaps *ret;
+ GstStructure *structure;
+ gint i;
+
+ ret = gst_caps_copy (caps);
+
+ /* When going from the SINK pad to the src, we just need to make sure the
+ * format is AYUV */
+ if (direction == GST_PAD_SINK) {
+ for (i = 0; i < gst_caps_get_size (ret); i++) {
+ structure = gst_caps_get_structure (ret, i);
+ gst_structure_set (structure, "format",
+ GST_TYPE_FOURCC, GST_MAKE_FOURCC ('A', 'Y', 'U', 'V'), NULL);
+ }
+ } else {
+ GstCaps *ayuv_caps;
+
+ /* In the other direction, prepend a copy of the caps with format AYUV,
+ * and set the first to I420 */
+ ayuv_caps = gst_caps_copy (ret);
+
+ for (i = 0; i < gst_caps_get_size (ret); i++) {
+ structure = gst_caps_get_structure (ret, i);
+ gst_structure_set (structure, "format",
+ GST_TYPE_FOURCC, GST_MAKE_FOURCC ('I', '4', '2', '0'), NULL);
+ }
+
+ gst_caps_append (ret, ayuv_caps);
+ }
+
+ gst_caps_do_simplify (ret);
+
+ return ret;
+}
+
+static gboolean
+gst_alpha_set_caps (GstBaseTransform * btrans,
+ GstCaps * incaps, GstCaps * outcaps)
+{
+ GstAlpha *alpha = GST_ALPHA (btrans);
+
+ if (!gst_video_format_parse_caps (incaps, &alpha->format,
+ &alpha->width, &alpha->height))
+ return FALSE;
+
+ if (alpha->format == GST_VIDEO_FORMAT_AYUV)
+ alpha->ayuv = TRUE;
+ else
+ alpha->ayuv = FALSE;
+
+ return TRUE;
+}
+
+static void
+gst_alpha_set_ayuv (guint8 * src, guint8 * dest, gint width, gint height,
+ gdouble alpha)
+{
+ gint b_alpha = (gint) (alpha * 255);
+ gint y, x;
+
+ for (y = 0; y < height; y++) {
+ for (x = 0; x < width; x++) {
+ *dest++ = (*src++ * b_alpha) >> 8;
+ *dest++ = *src++;
+ *dest++ = *src++;
+ *dest++ = *src++;
+ }
+ }
+}
+
+static void
+gst_alpha_set_i420 (guint8 * src, guint8 * dest, gint width, gint height,
+ gdouble alpha)
+{
+ gint b_alpha = (gint) (alpha * 255);
+ guint8 *srcY;
+ guint8 *srcU;
+ guint8 *srcV;
+ gint i, j;
+ gint src_wrap, src_uv_wrap;
+ gint y_stride, uv_stride;
+ gboolean odd_width;
+
+ y_stride = gst_video_format_get_row_stride (GST_VIDEO_FORMAT_I420, 0, width);
+ uv_stride = gst_video_format_get_row_stride (GST_VIDEO_FORMAT_I420, 1, width);
+
+ src_wrap = y_stride - width;
+ src_uv_wrap = uv_stride - (width / 2);
+
+ srcY = src;
+ srcU = src + gst_video_format_get_component_offset (GST_VIDEO_FORMAT_I420,
+ 1, width, height);
+ srcV = src + gst_video_format_get_component_offset (GST_VIDEO_FORMAT_I420,
+ 2, width, height);
+
+ odd_width = (width % 2 != 0);
+
+ for (i = 0; i < height; i++) {
+ for (j = 0; j < width / 2; j++) {
+ *dest++ = b_alpha;
+ *dest++ = *srcY++;
+ *dest++ = *srcU;
+ *dest++ = *srcV;
+ *dest++ = b_alpha;
+ *dest++ = *srcY++;
+ *dest++ = *srcU++;
+ *dest++ = *srcV++;
+ }
+ /* Might have one odd column left to do */
+ if (odd_width) {
+ *dest++ = b_alpha;
+ *dest++ = *srcY++;
+ *dest++ = *srcU;
+ *dest++ = *srcV;
+ }
+ if (i % 2 == 0) {
+ srcU -= width / 2;
+ srcV -= width / 2;
+ } else {
+ srcU += src_uv_wrap;
+ srcV += src_uv_wrap;
+ }
+ srcY += src_wrap;
+ }
+}
+
+static void
+gst_alpha_chroma_key_ayuv (guint8 * src, guint8 * dest, gint width, gint height,
+ GstAlpha * alpha)
+{
+ gint b_alpha;
+ guint8 *src1;
+ guint8 *dest1;
+ gint i, j;
+ gint x, z, u, v, y, a;
+ gint tmp, tmp1;
+ gint x1, y1;
+ gint smin, smax;
+
+ smin = 128 - alpha->black_sensitivity;
+ smax = 128 + alpha->white_sensitivity;
+
+ src1 = src;
+ dest1 = dest;
+
+ for (i = 0; i < height; i++) {
+ for (j = 0; j < width; j++) {
+ a = *src1++ * (alpha->alpha);
+ y = *src1++;
+ u = *src1++ - 128;
+ v = *src1++ - 128;
+
+ if (y < smin || y > smax) {
+ /* too dark or too bright, keep alpha */
+ b_alpha = a;
+ } else {
+ /* Convert foreground to XZ coords where X direction is defined by
+ the key color */
+ tmp = ((short) u * alpha->cb + (short) v * alpha->cr) >> 7;
+ x = CLAMP (tmp, -128, 127);
+ tmp = ((short) v * alpha->cb - (short) u * alpha->cr) >> 7;
+ z = CLAMP (tmp, -128, 127);
+
+ /* WARNING: accept angle should never be set greater than "somewhat less
+ than 90 degrees" to avoid dealing with negative/infinite tg. In reality,
+ 80 degrees should be enough if foreground is reasonable. If this seems
+ to be a problem, go to alternative ways of checking point position
+ (scalar product or line equations). This angle should not be too small
+ either to avoid infinite ctg (used to suppress foreground without use of
+ division) */
+
+ tmp = ((short) (x) * alpha->accept_angle_tg) >> 4;
+ tmp = MIN (tmp, 127);
+
+ if (abs (z) > tmp) {
+ /* keep foreground Kfg = 0 */
+ b_alpha = a;
+ } else {
+ /* Compute Kfg (implicitly) and Kbg, suppress foreground in XZ coord
+ according to Kfg */
+ tmp = ((short) (z) * alpha->accept_angle_ctg) >> 4;
+ tmp = CLAMP (tmp, -128, 127);
+ x1 = abs (tmp);
+ y1 = z;
+
+ tmp1 = x - x1;
+ tmp1 = MAX (tmp1, 0);
+ b_alpha = (((unsigned char) (tmp1) *
+ (unsigned short) (alpha->one_over_kc)) / 2);
+ b_alpha = 255 - CLAMP (b_alpha, 0, 255);
+ b_alpha = (a * b_alpha) >> 8;
+
+ tmp = ((unsigned short) (tmp1) * alpha->kfgy_scale) >> 4;
+ tmp1 = MIN (tmp, 255);
+
+ tmp = y - tmp1;
+ y = MAX (tmp, 0);
+
+ /* Convert suppressed foreground back to CbCr */
+ tmp = ((char) (x1) * (short) (alpha->cb) -
+ (char) (y1) * (short) (alpha->cr)) >> 7;
+ u = CLAMP (tmp, -128, 127);
+
+ tmp = ((char) (x1) * (short) (alpha->cr) +
+ (char) (y1) * (short) (alpha->cb)) >> 7;
+ v = CLAMP (tmp, -128, 127);
+
+ /* Deal with noise. For now, a circle around the key color with
+ radius of noise_level treated as exact key color. Introduces
+ sharp transitions.
+ */
+ tmp = z * (short) (z) + (x - alpha->kg) * (short) (x - alpha->kg);
+ tmp = MIN (tmp, 0xffff);
+
+ if (tmp < alpha->noise_level * alpha->noise_level) {
+ b_alpha = 0;
+ }
+ }
+ }
+
+ u += 128;
+ v += 128;
+
+ *dest1++ = b_alpha;
+ *dest1++ = y;
+ *dest1++ = u;
+ *dest1++ = v;
+ }
+ }
+}
+
+static void
+gst_alpha_chromakey_row_i420 (GstAlpha * alpha, guint8 * dest1, guint8 * dest2,
+ guint8 * srcY1, guint8 * srcY2, guint8 * srcU, guint8 * srcV, gint width)
+{
+ gint xpos;
+ gint b_alpha;
+ gint x, z, u, v, y11, y12, y21, y22, a;
+ gint tmp, tmp1;
+ gint x1, y1;
+ gint smin, smax;
+
+ a = 255 * alpha->alpha;
+ smin = 128 - alpha->black_sensitivity;
+ smax = 128 + alpha->white_sensitivity;
+
+ for (xpos = 0; xpos < width / 2; xpos++) {
+ y11 = *srcY1++;
+ y12 = *srcY1++;
+ y21 = *srcY2++;
+ y22 = *srcY2++;
+ u = *srcU++ - 128;
+ v = *srcV++ - 128;
+
+ if (y11 < smin || y11 > smax ||
+ y12 < smin || y12 > smax ||
+ y21 < smin || y21 > smax || y22 < smin || y22 > smax) {
+ /* too dark or too bright, make opaque */
+ b_alpha = 255;
+ } else {
+ /* Convert foreground to XZ coords where X direction is defined by
+ the key color */
+ tmp = ((short) u * alpha->cb + (short) v * alpha->cr) >> 7;
+ x = CLAMP (tmp, -128, 127);
+ tmp = ((short) v * alpha->cb - (short) u * alpha->cr) >> 7;
+ z = CLAMP (tmp, -128, 127);
+
+ /* WARNING: accept angle should never be set greater than "somewhat less
+ than 90 degrees" to avoid dealing with negative/infinite tg. In reality,
+ 80 degrees should be enough if foreground is reasonable. If this seems
+ to be a problem, go to alternative ways of checking point position
+ (scalar product or line equations). This angle should not be too small
+ either to avoid infinite ctg (used to suppress foreground without use of
+ division) */
+
+ tmp = ((short) (x) * alpha->accept_angle_tg) >> 4;
+ tmp = MIN (tmp, 127);
+
+ if (abs (z) > tmp) {
+ /* keep foreground Kfg = 0 */
+ b_alpha = 255;
+ } else {
+ /* Compute Kfg (implicitly) and Kbg, suppress foreground in XZ coord
+ according to Kfg */
+ tmp = ((short) (z) * alpha->accept_angle_ctg) >> 4;
+ tmp = CLAMP (tmp, -128, 127);
+ x1 = abs (tmp);
+ y1 = z;
+
+ tmp1 = x - x1;
+ tmp1 = MAX (tmp1, 0);
+ b_alpha = (((unsigned char) (tmp1) *
+ (unsigned short) (alpha->one_over_kc)) / 2);
+ b_alpha = 255 - CLAMP (b_alpha, 0, 255);
+ b_alpha = (a * b_alpha) >> 8;
+
+ tmp = ((unsigned short) (tmp1) * alpha->kfgy_scale) >> 4;
+ tmp1 = MIN (tmp, 255);
+
+ tmp = y11 - tmp1;
+ y11 = MAX (tmp, 0);
+ tmp = y12 - tmp1;
+ y12 = MAX (tmp, 0);
+ tmp = y21 - tmp1;
+ y21 = MAX (tmp, 0);
+ tmp = y22 - tmp1;
+ y22 = MAX (tmp, 0);
+
+ /* Convert suppressed foreground back to CbCr */
+ tmp = ((char) (x1) * (short) (alpha->cb) -
+ (char) (y1) * (short) (alpha->cr)) >> 7;
+ u = CLAMP (tmp, -128, 127);
+
+ tmp = ((char) (x1) * (short) (alpha->cr) +
+ (char) (y1) * (short) (alpha->cb)) >> 7;
+ v = CLAMP (tmp, -128, 127);
+
+ /* Deal with noise. For now, a circle around the key color with
+ radius of noise_level treated as exact key color. Introduces
+ sharp transitions.
+ */
+ tmp = z * (short) (z) + (x - alpha->kg) * (short) (x - alpha->kg);
+ tmp = MIN (tmp, 0xffff);
+
+ if (tmp < alpha->noise_level * alpha->noise_level) {
+ /* Uncomment this if you want total suppression within the noise circle */
+ b_alpha = 0;
+ }
+ }
+ }
+
+ u += 128;
+ v += 128;
+
+ *dest1++ = b_alpha;
+ *dest1++ = y11;
+ *dest1++ = u;
+ *dest1++ = v;
+ *dest1++ = b_alpha;
+ *dest1++ = y12;
+ *dest1++ = u;
+ *dest1++ = v;
+
+ *dest2++ = b_alpha;
+ *dest2++ = y21;
+ *dest2++ = u;
+ *dest2++ = v;
+ *dest2++ = b_alpha;
+ *dest2++ = y22;
+ *dest2++ = u;
+ *dest2++ = v;
+ }
+}
+
+/* based on http://www.cs.utah.edu/~michael/chroma/
+ */
+static void
+gst_alpha_chroma_key_i420 (guint8 * src, guint8 * dest, gint width, gint height,
+ GstAlpha * alpha)
+{
+ guint8 *srcY1, *srcY2, *srcU, *srcV;
+ guint8 *dest1, *dest2;
+ gint ypos;
+ gint dest_stride, src_y_stride, src_uv_stride;
+
+ dest_stride =
+ gst_video_format_get_row_stride (GST_VIDEO_FORMAT_AYUV, 0, width);
+ src_y_stride =
+ gst_video_format_get_row_stride (GST_VIDEO_FORMAT_I420, 0, width);
+ src_uv_stride =
+ gst_video_format_get_row_stride (GST_VIDEO_FORMAT_I420, 1, width);
+
+ srcY1 = src;
+ srcY2 = src + src_y_stride;
+
+ srcU = src + gst_video_format_get_component_offset (GST_VIDEO_FORMAT_I420,
+ 1, width, height);
+ srcV = src + gst_video_format_get_component_offset (GST_VIDEO_FORMAT_I420,
+ 2, width, height);
+
+ dest1 = dest;
+ dest2 = dest + dest_stride;
+
+ /* Redefine Y strides to skip 2 lines at a time ... */
+ dest_stride *= 2;
+ src_y_stride *= 2;
+
+ for (ypos = 0; ypos < height / 2; ypos++) {
+
+ gst_alpha_chromakey_row_i420 (alpha, dest1, dest2,
+ srcY1, srcY2, srcU, srcV, width);
+
+ dest1 += dest_stride;
+ dest2 += dest_stride;
+ srcY1 += src_y_stride;
+ srcY2 += src_y_stride;
+ srcU += src_uv_stride;
+ srcV += src_uv_stride;
+ }
+}
+
+static void
+gst_alpha_init_params (GstAlpha * alpha)
+{
+ float kgl;
+ float tmp;
+ float tmp1, tmp2;
+
+ alpha->y =
+ 0.257 * alpha->target_r + 0.504 * alpha->target_g +
+ 0.098 * alpha->target_b;
+ tmp1 =
+ -0.148 * alpha->target_r - 0.291 * alpha->target_g +
+ 0.439 * alpha->target_b;
+ tmp2 =
+ 0.439 * alpha->target_r - 0.368 * alpha->target_g -
+ 0.071 * alpha->target_b;
+ kgl = sqrt (tmp1 * tmp1 + tmp2 * tmp2);
+ alpha->cb = 127 * (tmp1 / kgl);
+ alpha->cr = 127 * (tmp2 / kgl);
+
+ alpha->accept_angle_cos = cos (M_PI * alpha->angle / 180);
+ alpha->accept_angle_sin = sin (M_PI * alpha->angle / 180);
+ tmp = 15 * tan (M_PI * alpha->angle / 180);
+ tmp = MIN (tmp, 255);
+ alpha->accept_angle_tg = tmp;
+ tmp = 15 / tan (M_PI * alpha->angle / 180);
+ tmp = MIN (tmp, 255);
+ alpha->accept_angle_ctg = tmp;
+ tmp = 1 / (kgl);
+ alpha->one_over_kc = 255 * 2 * tmp - 255;
+ tmp = 15 * (float) (alpha->y) / kgl;
+ tmp = MIN (tmp, 255);
+ alpha->kfgy_scale = tmp;
+ alpha->kg = MIN (kgl, 127);
+}
+
+static gboolean
+gst_alpha_start (GstBaseTransform * btrans)
+{
+ GstAlpha *alpha = GST_ALPHA (btrans);
+
+ gst_alpha_init_params (alpha);
+
+ return TRUE;
+}
+
+static GstFlowReturn
+gst_alpha_transform (GstBaseTransform * btrans, GstBuffer * in, GstBuffer * out)
+{
+ GstAlpha *alpha = GST_ALPHA (btrans);
+ gint width, height;
+ GstClockTime timestamp;
+
+ width = alpha->width;
+ height = alpha->height;
+
+ GST_BUFFER_TIMESTAMP (out) = GST_BUFFER_TIMESTAMP (in);
+ GST_BUFFER_DURATION (out) = GST_BUFFER_DURATION (in);
+ timestamp = gst_segment_to_stream_time (&btrans->segment, GST_FORMAT_TIME,
+ GST_BUFFER_TIMESTAMP (in));
+ GST_LOG ("Got stream time of %" GST_TIME_FORMAT, GST_TIME_ARGS (timestamp));
+ if (GST_CLOCK_TIME_IS_VALID (timestamp))
+ gst_object_sync_values (G_OBJECT (alpha), timestamp);
+
+ switch (alpha->method) {
+ case ALPHA_METHOD_SET:
+ if (alpha->ayuv) {
+ gst_alpha_set_ayuv (GST_BUFFER_DATA (in),
+ GST_BUFFER_DATA (out), width, height, alpha->alpha);
+ } else {
+ gst_alpha_set_i420 (GST_BUFFER_DATA (in),
+ GST_BUFFER_DATA (out), width, height, alpha->alpha);
+ }
+ break;
+ case ALPHA_METHOD_GREEN:
+ case ALPHA_METHOD_BLUE:
+ case ALPHA_METHOD_CUSTOM:
+ if (alpha->ayuv) {
+ gst_alpha_chroma_key_ayuv (GST_BUFFER_DATA (in),
+ GST_BUFFER_DATA (out), width, height, alpha);
+ } else {
+ gst_alpha_chroma_key_i420 (GST_BUFFER_DATA (in),
+ GST_BUFFER_DATA (out), width, height, alpha);
+ }
+ break;
+ default:
+ break;
+ }
+
+ return GST_FLOW_OK;
+}
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+ gst_controller_init (NULL, NULL);
+
+ return gst_element_register (plugin, "alpha", GST_RANK_NONE, GST_TYPE_ALPHA);
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+ GST_VERSION_MINOR,
+ "alpha",
+ "adds an alpha channel to video - constant or via chroma-keying",
+ plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)
+
+
+#ifdef __SYMBIAN32__
+EXPORT_C GstPluginDesc* _GST_PLUGIN_DESC()
+{
+ return &gst_plugin_desc;
+}
+
+#endif