gstreamer/ext/gl/gstglvideomixer.c
2014-09-30 20:39:36 +10:00

670 lines
21 KiB
C

/*
* GStreamer
* Copyright (C) 2009 Julien Isorce <julien.isorce@gmail.com>
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-glvideomixer
*
* Composites a number of streams into a single output scene using OpenGL in
* a similar fashion to compositor and videomixer.
*
* <refsect2>
* <title>Examples</title>
* |[
* gst-launch-1.0 glvideomixer name=m ! glimagesink \
* videotestsrc ! video/x-raw, format=YUY2 ! m. \
* videotestsrc pattern=12 ! video/x-raw, format=I420, framerate=5/1, width=100, height=200 ! queue ! m. \
* videotestsrc ! video/x-raw, format=RGB, framerate=15/1, width=1500, height=1500 ! gleffects effect=3 ! queue ! m. \
* videotestsrc ! gleffects effect=2 ! queue ! m. \
* videotestsrc ! glfiltercube ! queue ! m. \
* videotestsrc ! gleffects effect=6 ! queue ! m.
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstglvideomixer.h"
#define GST_CAT_DEFAULT gst_gl_video_mixer_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
enum
{
PROP_0,
PROP_BACKGROUND,
};
#define DEFAULT_BACKGROUND GST_GL_VIDEO_MIXER_BACKGROUND_CHECKER
#define DEBUG_INIT \
GST_DEBUG_CATEGORY_INIT (gst_gl_video_mixer_debug, "glvideomixer", 0, "glvideomixer element");
G_DEFINE_TYPE_WITH_CODE (GstGLVideoMixer, gst_gl_video_mixer, GST_TYPE_GL_MIXER,
DEBUG_INIT);
static void gst_gl_video_mixer_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_gl_video_mixer_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static gboolean _update_info (GstVideoAggregator * vagg, GstVideoInfo * info);
static void gst_gl_video_mixer_reset (GstGLMixer * mixer);
static gboolean gst_gl_video_mixer_init_shader (GstGLMixer * mixer,
GstCaps * outcaps);
static gboolean gst_gl_video_mixer_process_textures (GstGLMixer * mixer,
GPtrArray * in_frames, guint out_tex);
static void gst_gl_video_mixer_callback (gpointer stuff);
/* *INDENT-OFF* */
/* vertex source */
static const gchar *video_mixer_v_src =
"attribute vec4 a_position; \n"
"attribute vec2 a_texCoord; \n"
"varying vec2 v_texCoord; \n"
"void main() \n"
"{ \n"
" gl_Position = a_position; \n"
" v_texCoord = a_texCoord; \n" "}";
/* fragment source */
static const gchar *video_mixer_f_src =
"#ifdef GL_ES\n"
"precision mediump float;\n"
"#endif\n"
"uniform sampler2D texture; \n"
"uniform float alpha;\n"
"varying vec2 v_texCoord; \n"
"void main() \n"
"{ \n"
" vec4 rgba = texture2D( texture, v_texCoord );\n"
" gl_FragColor = vec4(rgba.rgb, rgba.a * alpha);\n"
"} \n";
/* checker vertex source */
static const gchar *checker_v_src =
"attribute vec4 a_position;\n"
"void main()\n"
"{\n"
" gl_Position = a_position;\n"
"}\n";
/* checker fragment source */
static const gchar *checker_f_src =
"#ifdef GL_ES\n"
"precision mediump float;\n"
"#endif\n"
"const float blocksize = 8.0;\n"
"void main ()\n"
"{\n"
" vec4 high = vec4(0.667, 0.667, 0.667, 1.0);\n"
" vec4 low = vec4(0.333, 0.333, 0.333, 1.0);\n"
" if (mod(gl_FragCoord.x, blocksize * 2.0) >= blocksize) {\n"
" if (mod(gl_FragCoord.y, blocksize * 2.0) >= blocksize)\n"
" gl_FragColor = low;\n"
" else\n"
" gl_FragColor = high;\n"
" } else {\n"
" if (mod(gl_FragCoord.y, blocksize * 2.0) < blocksize)\n"
" gl_FragColor = low;\n"
" else\n"
" gl_FragColor = high;\n"
" }\n"
"}\n";
/* *INDENT-ON* */
#define GST_TYPE_GL_VIDEO_MIXER_PAD (gst_gl_video_mixer_pad_get_type())
#define GST_GL_VIDEO_MIXER_PAD(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_GL_VIDEO_MIXER_PAD, GstGLVideoMixerPad))
#define GST_GL_VIDEO_MIXER_PAD_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_GL_VIDEO_MIXER_PAD, GstGLVideoMixerPadClass))
#define GST_IS_GL_VIDEO_MIXER_PAD(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_GL_VIDEO_MIXER_PAD))
#define GST_IS_GL_VIDEO_MIXER_PAD_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_GL_VIDEO_MIXER_PAD))
typedef struct _GstGLVideoMixerPad GstGLVideoMixerPad;
typedef struct _GstGLVideoMixerPadClass GstGLVideoMixerPadClass;
typedef struct _GstGLVideoMixerCollect GstGLVideoMixerCollect;
/**
* GstGLVideoMixerPad:
*
* The opaque #GstGLVideoMixerPad structure.
*/
struct _GstGLVideoMixerPad
{
GstGLMixerPad parent;
/* < private > */
/* properties */
gint xpos, ypos;
gint width, height;
gdouble alpha;
};
struct _GstGLVideoMixerPadClass
{
GstGLMixerPadClass parent_class;
};
GType gst_gl_video_mixer_pad_get_type (void);
G_DEFINE_TYPE (GstGLVideoMixerPad, gst_gl_video_mixer_pad,
GST_TYPE_GL_MIXER_PAD);
static void gst_gl_video_mixer_pad_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_gl_video_mixer_pad_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
#define DEFAULT_PAD_XPOS 0
#define DEFAULT_PAD_YPOS 0
#define DEFAULT_PAD_WIDTH 0
#define DEFAULT_PAD_HEIGHT 0
#define DEFAULT_PAD_ALPHA 1.0
enum
{
PROP_PAD_0,
PROP_PAD_XPOS,
PROP_PAD_YPOS,
PROP_PAD_WIDTH,
PROP_PAD_HEIGHT,
PROP_PAD_ALPHA
};
static void
gst_gl_video_mixer_pad_init (GstGLVideoMixerPad * pad)
{
pad->alpha = 1.0;
}
static void
gst_gl_video_mixer_pad_class_init (GstGLVideoMixerPadClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
gobject_class->set_property = gst_gl_video_mixer_pad_set_property;
gobject_class->get_property = gst_gl_video_mixer_pad_get_property;
g_object_class_install_property (gobject_class, PROP_PAD_XPOS,
g_param_spec_int ("xpos", "X Position", "X Position of the picture",
G_MININT, G_MAXINT, DEFAULT_PAD_XPOS,
G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_PAD_YPOS,
g_param_spec_int ("ypos", "Y Position", "Y Position of the picture",
G_MININT, G_MAXINT, DEFAULT_PAD_YPOS,
G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_PAD_WIDTH,
g_param_spec_int ("width", "Width", "Width of the picture",
G_MININT, G_MAXINT, DEFAULT_PAD_WIDTH,
G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_PAD_HEIGHT,
g_param_spec_int ("height", "Height", "Height of the picture",
G_MININT, G_MAXINT, DEFAULT_PAD_HEIGHT,
G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_PAD_ALPHA,
g_param_spec_double ("alpha", "Alpha", "Alpha of the picture", 0.0, 1.0,
DEFAULT_PAD_ALPHA,
G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS));
}
static void
gst_gl_video_mixer_pad_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstGLVideoMixerPad *pad = GST_GL_VIDEO_MIXER_PAD (object);
switch (prop_id) {
case PROP_PAD_XPOS:
g_value_set_int (value, pad->xpos);
break;
case PROP_PAD_YPOS:
g_value_set_int (value, pad->ypos);
break;
case PROP_PAD_WIDTH:
g_value_set_int (value, pad->width);
break;
case PROP_PAD_HEIGHT:
g_value_set_int (value, pad->height);
break;
case PROP_PAD_ALPHA:
g_value_set_double (value, pad->alpha);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_gl_video_mixer_pad_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstGLVideoMixerPad *pad = GST_GL_VIDEO_MIXER_PAD (object);
GstGLMixer *mix = GST_GL_MIXER (gst_pad_get_parent (GST_PAD (pad)));
switch (prop_id) {
case PROP_PAD_XPOS:
pad->xpos = g_value_get_int (value);
break;
case PROP_PAD_YPOS:
pad->ypos = g_value_get_int (value);
break;
case PROP_PAD_WIDTH:
pad->width = g_value_get_int (value);
break;
case PROP_PAD_HEIGHT:
pad->height = g_value_get_int (value);
break;
case PROP_PAD_ALPHA:
pad->alpha = g_value_get_double (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
gst_object_unref (mix);
}
#define GST_GL_TYPE_VIDEO_MIXER_BACKGROUND (gst_gl_video_mixer_background_get_type())
static GType
gst_gl_video_mixer_background_get_type (void)
{
static GType mixer_background_type = 0;
static const GEnumValue mixer_background[] = {
{GST_GL_VIDEO_MIXER_BACKGROUND_CHECKER, "Checker pattern", "checker"},
{GST_GL_VIDEO_MIXER_BACKGROUND_BLACK, "Black", "black"},
{GST_GL_VIDEO_MIXER_BACKGROUND_WHITE, "White", "white"},
{GST_GL_VIDEO_MIXER_BACKGROUND_TRANSPARENT,
"Transparent Background to enable further compositing", "transparent"},
{0, NULL, NULL},
};
if (!mixer_background_type) {
mixer_background_type =
g_enum_register_static ("GstGLVideoMixerBackground", mixer_background);
}
return mixer_background_type;
}
static void
gst_gl_video_mixer_class_init (GstGLVideoMixerClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *element_class;
GstAggregatorClass *agg_class = (GstAggregatorClass *) klass;
GstVideoAggregatorClass *vagg_class = (GstVideoAggregatorClass *) klass;
gobject_class = (GObjectClass *) klass;
element_class = GST_ELEMENT_CLASS (klass);
gobject_class->set_property = gst_gl_video_mixer_set_property;
gobject_class->get_property = gst_gl_video_mixer_get_property;
gst_element_class_set_metadata (element_class, "OpenGL video_mixer",
"Filter/Effect/Video/Compositor", "OpenGL video_mixer",
"Julien Isorce <julien.isorce@gmail.com>");
g_object_class_install_property (gobject_class, PROP_BACKGROUND,
g_param_spec_enum ("background", "Background", "Background type",
GST_GL_TYPE_VIDEO_MIXER_BACKGROUND,
DEFAULT_BACKGROUND, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
GST_GL_MIXER_CLASS (klass)->set_caps = gst_gl_video_mixer_init_shader;
GST_GL_MIXER_CLASS (klass)->reset = gst_gl_video_mixer_reset;
GST_GL_MIXER_CLASS (klass)->process_textures =
gst_gl_video_mixer_process_textures;
vagg_class->update_info = _update_info;
agg_class->sinkpads_type = GST_TYPE_GL_VIDEO_MIXER_PAD;
}
static void
gst_gl_video_mixer_init (GstGLVideoMixer * video_mixer)
{
video_mixer->background = DEFAULT_BACKGROUND;
video_mixer->shader = NULL;
video_mixer->input_frames = NULL;
}
static void
gst_gl_video_mixer_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstGLVideoMixer *mixer = GST_GL_VIDEO_MIXER (object);
switch (prop_id) {
case PROP_BACKGROUND:
mixer->background = g_value_get_enum (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_gl_video_mixer_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstGLVideoMixer *mixer = GST_GL_VIDEO_MIXER (object);
switch (prop_id) {
case PROP_BACKGROUND:
g_value_set_enum (value, mixer->background);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
_update_info (GstVideoAggregator * vagg, GstVideoInfo * info)
{
GList *l;
gint best_width = -1, best_height = -1;
gboolean ret = FALSE;
GST_OBJECT_LOCK (vagg);
for (l = GST_ELEMENT (vagg)->sinkpads; l; l = l->next) {
GstVideoAggregatorPad *vaggpad = l->data;
GstGLVideoMixerPad *mixer_pad = GST_GL_VIDEO_MIXER_PAD (vaggpad);
gint this_width, this_height;
gint width, height;
if (mixer_pad->width > 0)
width = mixer_pad->width;
else
width = GST_VIDEO_INFO_WIDTH (&vaggpad->info);
if (mixer_pad->height > 0)
height = mixer_pad->height;
else
height = GST_VIDEO_INFO_HEIGHT (&vaggpad->info);
if (width == 0 || height == 0)
continue;
this_width = width + MAX (mixer_pad->xpos, 0);
this_height = height + MAX (mixer_pad->ypos, 0);
if (best_width < this_width)
best_width = this_width;
if (best_height < this_height)
best_height = this_height;
}
GST_OBJECT_UNLOCK (vagg);
if (best_width > 0 && best_height > 0) {
info->width = best_width;
info->height = best_height;
ret = TRUE;
}
return ret;
}
static void
gst_gl_video_mixer_reset (GstGLMixer * mixer)
{
GstGLVideoMixer *video_mixer = GST_GL_VIDEO_MIXER (mixer);
video_mixer->input_frames = NULL;
if (video_mixer->shader)
gst_gl_context_del_shader (mixer->context, video_mixer->shader);
video_mixer->shader = NULL;
if (video_mixer->checker)
gst_gl_context_del_shader (mixer->context, video_mixer->checker);
video_mixer->checker = NULL;
}
static gboolean
gst_gl_video_mixer_init_shader (GstGLMixer * mixer, GstCaps * outcaps)
{
GstGLVideoMixer *video_mixer = GST_GL_VIDEO_MIXER (mixer);
if (video_mixer->shader)
gst_gl_context_del_shader (mixer->context, video_mixer->shader);
return gst_gl_context_gen_shader (mixer->context, video_mixer_v_src,
video_mixer_f_src, &video_mixer->shader);
}
static gboolean
gst_gl_video_mixer_process_textures (GstGLMixer * mix, GPtrArray * frames,
guint out_tex)
{
GstGLVideoMixer *video_mixer = GST_GL_VIDEO_MIXER (mix);
video_mixer->input_frames = frames;
gst_gl_context_use_fbo_v2 (mix->context,
GST_VIDEO_INFO_WIDTH (&GST_VIDEO_AGGREGATOR (mix)->info),
GST_VIDEO_INFO_HEIGHT (&GST_VIDEO_AGGREGATOR (mix)->info),
mix->fbo, mix->depthbuffer,
out_tex, gst_gl_video_mixer_callback, (gpointer) video_mixer);
return TRUE;
}
static gboolean
_draw_checker_background (GstGLVideoMixer * video_mixer)
{
GstGLMixer *mixer = GST_GL_MIXER (video_mixer);
const GstGLFuncs *gl = mixer->context->gl_vtable;
gint attr_position_loc = 0;
const GLushort indices[] = {
0, 1, 2,
0, 2, 3
};
/* *INDENT-OFF* */
gfloat v_vertices[] = {
-1.0,-1.0,-1.0f,
1.0,-1.0,-1.0f,
1.0, 1.0,-1.0f,
-1.0, 1.0,-1.0f,
};
/* *INDENT-ON* */
if (!video_mixer->checker) {
if (!gst_gl_context_gen_shader (mixer->context, checker_v_src,
checker_f_src, &video_mixer->checker))
return FALSE;
}
gst_gl_shader_use (video_mixer->checker);
attr_position_loc =
gst_gl_shader_get_attribute_location (video_mixer->checker, "a_position");
gl->VertexAttribPointer (attr_position_loc, 3, GL_FLOAT,
GL_FALSE, 3 * sizeof (GLfloat), &v_vertices[0]);
gl->EnableVertexAttribArray (attr_position_loc);
gl->DrawElements (GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
return TRUE;
}
static gboolean
_draw_background (GstGLVideoMixer * video_mixer)
{
GstGLMixer *mixer = GST_GL_MIXER (video_mixer);
const GstGLFuncs *gl = mixer->context->gl_vtable;
switch (video_mixer->background) {
case GST_GL_VIDEO_MIXER_BACKGROUND_BLACK:
gl->ClearColor (0.0, 0.0, 0.0, 1.0);
gl->Clear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
break;
case GST_GL_VIDEO_MIXER_BACKGROUND_WHITE:
gl->ClearColor (1.0, 1.0, 1.0, 1.0);
gl->Clear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
break;
case GST_GL_VIDEO_MIXER_BACKGROUND_TRANSPARENT:
gl->ClearColor (0.0, 0.0, 0.0, 0.0);
gl->Clear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
break;
case GST_GL_VIDEO_MIXER_BACKGROUND_CHECKER:
return _draw_checker_background (video_mixer);
break;
default:
break;
}
return TRUE;
}
/* opengl scene, params: input texture (not the output mixer->texture) */
static void
gst_gl_video_mixer_callback (gpointer stuff)
{
GstGLVideoMixer *video_mixer = GST_GL_VIDEO_MIXER (stuff);
GstGLMixer *mixer = GST_GL_MIXER (video_mixer);
GstGLFuncs *gl = mixer->context->gl_vtable;
GLint attr_position_loc = 0;
GLint attr_texture_loc = 0;
guint out_width, out_height;
const GLushort indices[] = {
0, 1, 2,
0, 2, 3
};
guint count = 0;
out_width = GST_VIDEO_INFO_WIDTH (&GST_VIDEO_AGGREGATOR (stuff)->info);
out_height = GST_VIDEO_INFO_HEIGHT (&GST_VIDEO_AGGREGATOR (stuff)->info);
gst_gl_context_clear_shader (mixer->context);
gl->BindTexture (GL_TEXTURE_2D, 0);
gl->Disable (GL_TEXTURE_2D);
gl->Disable (GL_DEPTH_TEST);
gl->Disable (GL_CULL_FACE);
if (!_draw_background (video_mixer))
return;
gst_gl_shader_use (video_mixer->shader);
attr_position_loc =
gst_gl_shader_get_attribute_location (video_mixer->shader, "a_position");
attr_texture_loc =
gst_gl_shader_get_attribute_location (video_mixer->shader, "a_texCoord");
gl->Enable (GL_BLEND);
while (count < video_mixer->input_frames->len) {
GstGLMixerFrameData *frame;
GstGLVideoMixerPad *pad;
/* *INDENT-OFF* */
gfloat v_vertices[] = {
/* front face */
-1.0,-1.0,-1.0f, 0.0f, 0.0f,
1.0,-1.0,-1.0f, 1.0f, 0.0f,
1.0, 1.0,-1.0f, 1.0f, 1.0f,
-1.0, 1.0,-1.0f, 0.0f, 1.0f,
};
/* *INDENT-ON* */
guint in_tex;
guint in_width, in_height;
guint pad_width, pad_height;
gfloat w, h;
frame = g_ptr_array_index (video_mixer->input_frames, count);
if (!frame) {
GST_DEBUG ("skipping texture, null frame");
count++;
continue;
}
pad = (GstGLVideoMixerPad *) frame->pad;
in_width = GST_VIDEO_INFO_WIDTH (&GST_VIDEO_AGGREGATOR_PAD (pad)->info);
in_height = GST_VIDEO_INFO_HEIGHT (&GST_VIDEO_AGGREGATOR_PAD (pad)->info);
if (!frame->texture || in_width <= 0 || in_height <= 0
|| pad->alpha == 0.0f) {
GST_DEBUG ("skipping texture:%u frame:%p width:%u height:%u alpha:%f",
frame->texture, frame, in_width, in_height, pad->alpha);
count++;
continue;
}
in_tex = frame->texture;
pad_width = pad->width <= 0 ? in_width : pad->width;
pad_height = pad->height <= 0 ? in_height : pad->height;
w = ((gfloat) pad_width / (gfloat) out_width);
h = ((gfloat) pad_height / (gfloat) out_height);
/* top-left */
v_vertices[0] = v_vertices[15] =
2.0f * (gfloat) pad->xpos / (gfloat) out_width - 1.0f;
/* bottom-left */
v_vertices[1] = v_vertices[6] =
2.0f * (gfloat) pad->ypos / (gfloat) out_height - 1.0f;
/* top-right */
v_vertices[5] = v_vertices[10] = v_vertices[0] + 2.0f * w;
/* bottom-right */
v_vertices[11] = v_vertices[16] = v_vertices[1] + 2.0f * h;
GST_TRACE ("processing texture:%u dimensions:%ux%u, at %f,%f %fx%f with "
"alpha:%f", in_tex, in_width, in_height, v_vertices[0], v_vertices[1],
v_vertices[5], v_vertices[11], pad->alpha);
gl->VertexAttribPointer (attr_position_loc, 3, GL_FLOAT,
GL_FALSE, 5 * sizeof (GLfloat), &v_vertices[0]);
gl->VertexAttribPointer (attr_texture_loc, 2, GL_FLOAT,
GL_FALSE, 5 * sizeof (GLfloat), &v_vertices[3]);
gl->EnableVertexAttribArray (attr_position_loc);
gl->EnableVertexAttribArray (attr_texture_loc);
gl->BlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
gl->BlendEquation (GL_FUNC_ADD);
gl->ActiveTexture (GL_TEXTURE0);
gl->BindTexture (GL_TEXTURE_2D, in_tex);
gst_gl_shader_set_uniform_1i (video_mixer->shader, "texture", 0);
gst_gl_shader_set_uniform_1f (video_mixer->shader, "alpha", pad->alpha);
gl->DrawElements (GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);
++count;
}
gl->DisableVertexAttribArray (attr_position_loc);
gl->DisableVertexAttribArray (attr_texture_loc);
gl->BindTexture (GL_TEXTURE_2D, 0);
gl->Disable (GL_BLEND);
gst_gl_context_clear_shader (mixer->context);
}