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https://gitlab.freedesktop.org/gstreamer/gstreamer.git
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0620797a18
Convert the alpha value to 0->255 when setting and to 0->256 when using as a scaling factor. This makes sure we can reach the full opacity value of 0xff in all cases.
923 lines
27 KiB
C
923 lines
27 KiB
C
/* GStreamer
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* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
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* Copyright (C) <2007> Wim Taymans <wim.taymans@collabora.co.uk>
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* Copyright (C) <2007> Edward Hervey <edward.hervey@collabora.co.uk>
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* Copyright (C) <2007> Jan Schmidt <thaytan@noraisin.net>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <gst/gst.h>
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#include <gst/base/gstbasetransform.h>
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#include <gst/video/video.h>
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#include <gst/controller/gstcontroller.h>
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#include <stdlib.h>
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#include <string.h>
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#include <math.h>
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#ifndef M_PI
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#define M_PI 3.14159265358979323846
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#endif
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#define GST_TYPE_ALPHA \
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(gst_alpha_get_type())
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#define GST_ALPHA(obj) \
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(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_ALPHA,GstAlpha))
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#define GST_ALPHA_CLASS(klass) \
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(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ALPHA,GstAlphaClass))
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#define GST_IS_ALPHA(obj) \
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(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ALPHA))
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#define GST_IS_ALPHA_CLASS(klass) \
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(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ALPHA))
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typedef struct _GstAlpha GstAlpha;
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typedef struct _GstAlphaClass GstAlphaClass;
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typedef enum
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{
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ALPHA_METHOD_SET,
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ALPHA_METHOD_GREEN,
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ALPHA_METHOD_BLUE,
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ALPHA_METHOD_CUSTOM,
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}
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GstAlphaMethod;
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GST_DEBUG_CATEGORY_STATIC (gst_alpha_debug);
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#define GST_CAT_DEFAULT gst_alpha_debug
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struct _GstAlpha
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{
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GstBaseTransform parent;
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/* caps */
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GstVideoFormat format;
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gint width, height;
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gboolean ayuv;
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gdouble alpha;
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guint target_r;
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guint target_g;
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guint target_b;
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GstAlphaMethod method;
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gfloat angle;
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gfloat noise_level;
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guint black_sensitivity;
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guint white_sensitivity;
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gfloat y; /* chroma color */
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gint8 cb, cr;
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gint8 kg;
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gfloat accept_angle_cos;
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gfloat accept_angle_sin;
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guint8 accept_angle_tg;
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guint8 accept_angle_ctg;
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guint8 one_over_kc;
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guint8 kfgy_scale;
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};
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struct _GstAlphaClass
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{
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GstBaseTransformClass parent_class;
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};
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/* elementfactory information */
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static const GstElementDetails gst_alpha_details =
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GST_ELEMENT_DETAILS ("Alpha filter",
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"Filter/Effect/Video",
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"Adds an alpha channel to video - uniform or via chroma-keying",
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"Wim Taymans <wim@fluendo.com>\n"
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"Edward Hervey <edward.hervey@collabora.co.uk>\n"
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"Jan Schmidt <thaytan@noraisin.net>");
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/* Alpha signals and args */
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enum
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{
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/* FILL ME */
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LAST_SIGNAL
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};
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#define DEFAULT_METHOD ALPHA_METHOD_SET
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#define DEFAULT_ALPHA 1.0
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#define DEFAULT_TARGET_R 0
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#define DEFAULT_TARGET_G 255
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#define DEFAULT_TARGET_B 0
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#define DEFAULT_ANGLE 20.0
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#define DEFAULT_NOISE_LEVEL 2.0
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#define DEFAULT_BLACK_SENSITIVITY 100
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#define DEFAULT_WHITE_SENSITIVITY 100
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enum
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{
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PROP_0,
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PROP_METHOD,
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PROP_ALPHA,
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PROP_TARGET_R,
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PROP_TARGET_G,
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PROP_TARGET_B,
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PROP_ANGLE,
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PROP_NOISE_LEVEL,
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PROP_BLACK_SENSITIVITY,
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PROP_WHITE_SENSITIVITY,
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PROP_LAST
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};
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static GstStaticPadTemplate gst_alpha_src_template =
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GST_STATIC_PAD_TEMPLATE ("src",
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GST_PAD_SRC,
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GST_PAD_ALWAYS,
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GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV"))
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);
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static GstStaticPadTemplate gst_alpha_sink_template =
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GST_STATIC_PAD_TEMPLATE ("sink",
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GST_PAD_SINK,
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GST_PAD_ALWAYS,
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GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV") ";" GST_VIDEO_CAPS_YUV ("I420")
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)
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);
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static gboolean gst_alpha_start (GstBaseTransform * trans);
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static gboolean gst_alpha_get_unit_size (GstBaseTransform * btrans,
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GstCaps * caps, guint * size);
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static GstCaps *gst_alpha_transform_caps (GstBaseTransform * btrans,
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GstPadDirection direction, GstCaps * caps);
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static gboolean gst_alpha_set_caps (GstBaseTransform * btrans,
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GstCaps * incaps, GstCaps * outcaps);
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static GstFlowReturn gst_alpha_transform (GstBaseTransform * btrans,
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GstBuffer * in, GstBuffer * out);
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static void gst_alpha_init_params (GstAlpha * alpha);
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static void gst_alpha_set_property (GObject * object, guint prop_id,
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const GValue * value, GParamSpec * pspec);
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static void gst_alpha_get_property (GObject * object, guint prop_id,
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GValue * value, GParamSpec * pspec);
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GST_BOILERPLATE (GstAlpha, gst_alpha, GstBaseTransform,
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GST_TYPE_BASE_TRANSFORM);
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#define GST_TYPE_ALPHA_METHOD (gst_alpha_method_get_type())
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static GType
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gst_alpha_method_get_type (void)
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{
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static GType alpha_method_type = 0;
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static const GEnumValue alpha_method[] = {
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{ALPHA_METHOD_SET, "Set/adjust alpha channel", "set"},
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{ALPHA_METHOD_GREEN, "Chroma Key green", "green"},
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{ALPHA_METHOD_BLUE, "Chroma Key blue", "blue"},
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{ALPHA_METHOD_CUSTOM, "Chroma Key on target_r/g/b", "custom"},
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{0, NULL, NULL},
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};
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if (!alpha_method_type) {
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alpha_method_type = g_enum_register_static ("GstAlphaMethod", alpha_method);
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}
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return alpha_method_type;
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}
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static void
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gst_alpha_base_init (gpointer g_class)
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{
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GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
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gst_element_class_set_details (element_class, &gst_alpha_details);
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gst_element_class_add_pad_template (element_class,
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gst_static_pad_template_get (&gst_alpha_sink_template));
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gst_element_class_add_pad_template (element_class,
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gst_static_pad_template_get (&gst_alpha_src_template));
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GST_DEBUG_CATEGORY_INIT (gst_alpha_debug, "alpha", 0,
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"alpha - Element for adding alpha channel to streams");
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}
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static void
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gst_alpha_class_init (GstAlphaClass * klass)
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{
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GObjectClass *gobject_class;
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GstBaseTransformClass *btrans_class;
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gobject_class = (GObjectClass *) klass;
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btrans_class = (GstBaseTransformClass *) klass;
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gobject_class->set_property = gst_alpha_set_property;
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gobject_class->get_property = gst_alpha_get_property;
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g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_METHOD,
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g_param_spec_enum ("method", "Method",
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"How the alpha channels should be created", GST_TYPE_ALPHA_METHOD,
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DEFAULT_METHOD, (GParamFlags) G_PARAM_READWRITE));
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g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_ALPHA,
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g_param_spec_double ("alpha", "Alpha", "The value for the alpha channel",
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0.0, 1.0, DEFAULT_ALPHA,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TARGET_R,
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g_param_spec_uint ("target_r", "Target Red", "The Red target", 0, 255,
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DEFAULT_TARGET_R,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TARGET_G,
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g_param_spec_uint ("target_g", "Target Green", "The Green target", 0, 255,
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DEFAULT_TARGET_G,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TARGET_B,
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g_param_spec_uint ("target_b", "Target Blue", "The Blue target", 0, 255,
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DEFAULT_TARGET_B,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_ANGLE,
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g_param_spec_float ("angle", "Angle", "Size of the colorcube to change",
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0.0, 90.0, DEFAULT_ANGLE,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_NOISE_LEVEL,
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g_param_spec_float ("noise_level", "Noise Level", "Size of noise radius",
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0.0, 64.0, DEFAULT_NOISE_LEVEL,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (G_OBJECT_CLASS (klass),
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PROP_BLACK_SENSITIVITY, g_param_spec_uint ("black-sensitivity",
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"Black Sensitivity", "Sensitivity to dark colors", 0, 128,
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DEFAULT_BLACK_SENSITIVITY,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (G_OBJECT_CLASS (klass),
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PROP_WHITE_SENSITIVITY, g_param_spec_uint ("white-sensitivity",
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"Sensitivity", "Sensitivity to bright colors", 0, 128,
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DEFAULT_WHITE_SENSITIVITY,
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(GParamFlags) G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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btrans_class->start = GST_DEBUG_FUNCPTR (gst_alpha_start);
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btrans_class->transform = GST_DEBUG_FUNCPTR (gst_alpha_transform);
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btrans_class->get_unit_size = GST_DEBUG_FUNCPTR (gst_alpha_get_unit_size);
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btrans_class->transform_caps = GST_DEBUG_FUNCPTR (gst_alpha_transform_caps);
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btrans_class->set_caps = GST_DEBUG_FUNCPTR (gst_alpha_set_caps);
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}
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static void
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gst_alpha_init (GstAlpha * alpha, GstAlphaClass * klass)
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{
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alpha->alpha = DEFAULT_ALPHA;
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alpha->method = DEFAULT_METHOD;
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alpha->target_r = DEFAULT_TARGET_R;
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alpha->target_g = DEFAULT_TARGET_G;
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alpha->target_b = DEFAULT_TARGET_B;
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alpha->angle = DEFAULT_ANGLE;
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alpha->noise_level = DEFAULT_NOISE_LEVEL;
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alpha->black_sensitivity = DEFAULT_BLACK_SENSITIVITY;
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alpha->white_sensitivity = DEFAULT_WHITE_SENSITIVITY;
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}
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/* do we need this function? */
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static void
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gst_alpha_set_property (GObject * object, guint prop_id,
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const GValue * value, GParamSpec * pspec)
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{
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GstAlpha *alpha;
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g_return_if_fail (GST_IS_ALPHA (object));
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alpha = GST_ALPHA (object);
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switch (prop_id) {
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case PROP_METHOD:
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alpha->method = g_value_get_enum (value);
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switch (alpha->method) {
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case ALPHA_METHOD_GREEN:
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alpha->target_r = 0;
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alpha->target_g = 255;
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alpha->target_b = 0;
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break;
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case ALPHA_METHOD_BLUE:
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alpha->target_r = 0;
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alpha->target_g = 0;
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alpha->target_b = 255;
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break;
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default:
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break;
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}
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gst_alpha_init_params (alpha);
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break;
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case PROP_ALPHA:
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alpha->alpha = g_value_get_double (value);
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break;
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case PROP_TARGET_R:
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alpha->target_r = g_value_get_uint (value);
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gst_alpha_init_params (alpha);
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break;
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case PROP_TARGET_G:
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alpha->target_g = g_value_get_uint (value);
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gst_alpha_init_params (alpha);
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break;
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case PROP_TARGET_B:
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alpha->target_b = g_value_get_uint (value);
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gst_alpha_init_params (alpha);
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break;
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case PROP_ANGLE:
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alpha->angle = g_value_get_float (value);
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gst_alpha_init_params (alpha);
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break;
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case PROP_NOISE_LEVEL:
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alpha->noise_level = g_value_get_float (value);
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gst_alpha_init_params (alpha);
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break;
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case PROP_BLACK_SENSITIVITY:
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alpha->black_sensitivity = g_value_get_uint (value);
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break;
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case PROP_WHITE_SENSITIVITY:
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alpha->white_sensitivity = g_value_get_uint (value);
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break;
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default:
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G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
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break;
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}
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}
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static void
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gst_alpha_get_property (GObject * object, guint prop_id, GValue * value,
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GParamSpec * pspec)
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{
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GstAlpha *alpha;
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g_return_if_fail (GST_IS_ALPHA (object));
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alpha = GST_ALPHA (object);
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switch (prop_id) {
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case PROP_METHOD:
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g_value_set_enum (value, alpha->method);
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break;
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case PROP_ALPHA:
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g_value_set_double (value, alpha->alpha);
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break;
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case PROP_TARGET_R:
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g_value_set_uint (value, alpha->target_r);
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break;
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case PROP_TARGET_G:
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g_value_set_uint (value, alpha->target_g);
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break;
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case PROP_TARGET_B:
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g_value_set_uint (value, alpha->target_b);
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break;
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case PROP_ANGLE:
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g_value_set_float (value, alpha->angle);
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break;
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case PROP_NOISE_LEVEL:
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g_value_set_float (value, alpha->noise_level);
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break;
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case PROP_BLACK_SENSITIVITY:
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g_value_set_uint (value, alpha->black_sensitivity);
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break;
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case PROP_WHITE_SENSITIVITY:
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g_value_set_uint (value, alpha->white_sensitivity);
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break;
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default:
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G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
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break;
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}
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}
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static gboolean
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gst_alpha_get_unit_size (GstBaseTransform * btrans,
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GstCaps * caps, guint * size)
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{
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GstVideoFormat format;
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gint width, height;
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if (!gst_video_format_parse_caps (caps, &format, &width, &height))
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return FALSE;
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*size = gst_video_format_get_size (format, width, height);
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GST_DEBUG_OBJECT (btrans, "unit size = %d for format %d w %d height %d",
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*size, format, width, height);
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return TRUE;
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}
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static GstCaps *
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gst_alpha_transform_caps (GstBaseTransform * btrans,
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GstPadDirection direction, GstCaps * caps)
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{
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GstCaps *ret;
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GstStructure *structure;
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gint i;
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ret = gst_caps_copy (caps);
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/* When going from the SINK pad to the src, we just need to make sure the
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* format is AYUV */
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if (direction == GST_PAD_SINK) {
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for (i = 0; i < gst_caps_get_size (ret); i++) {
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structure = gst_caps_get_structure (ret, i);
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gst_structure_set (structure, "format",
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GST_TYPE_FOURCC, GST_MAKE_FOURCC ('A', 'Y', 'U', 'V'), NULL);
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}
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} else {
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GstCaps *ayuv_caps;
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/* In the other direction, prepend a copy of the caps with format AYUV,
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* and set the first to I420 */
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ayuv_caps = gst_caps_copy (ret);
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for (i = 0; i < gst_caps_get_size (ret); i++) {
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structure = gst_caps_get_structure (ret, i);
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gst_structure_set (structure, "format",
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GST_TYPE_FOURCC, GST_MAKE_FOURCC ('I', '4', '2', '0'), NULL);
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}
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gst_caps_append (ret, ayuv_caps);
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}
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gst_caps_do_simplify (ret);
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return ret;
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}
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static gboolean
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gst_alpha_set_caps (GstBaseTransform * btrans,
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GstCaps * incaps, GstCaps * outcaps)
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{
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GstAlpha *alpha = GST_ALPHA (btrans);
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if (!gst_video_format_parse_caps (incaps, &alpha->format,
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&alpha->width, &alpha->height))
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return FALSE;
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if (alpha->format == GST_VIDEO_FORMAT_AYUV)
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alpha->ayuv = TRUE;
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else
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alpha->ayuv = FALSE;
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return TRUE;
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}
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static void
|
|
gst_alpha_set_ayuv (guint8 * src, guint8 * dest, gint width, gint height,
|
|
gdouble alpha)
|
|
{
|
|
gint s_alpha = CLAMP ((gint) (alpha * 256), 0, 256);
|
|
gint y, x;
|
|
|
|
for (y = 0; y < height; y++) {
|
|
for (x = 0; x < width; x++) {
|
|
*dest++ = (*src++ * s_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 = CLAMP ((gint) (alpha * 255), 0, 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)
|