gstreamer/ext/qt/gstqsgtexture.cc
Matthew Waters b1bbdceeb2 new qt5 qml GL video sink
Very much in the same spirit as the Gtk GL sink

Two things are provided
1. A QQuickItem subclass that renders out RGBA filled GstGLMemory
   buffers that is instantiated from qml.
2. A sink element that will push buffers into (1)

To use
1. Declare the GstGLVideoItem in qml with an appropriate
   objectName property set.
2. Get the aforementioned GstGLVideoItem from qml using something like

QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

QObject *rootObject = engine.rootObjects().first();
QQuickItem *videoItem = rootObject->findChild<QQuickItem *> ("videoItem");

3. Set the videoItem on the sink

https://bugzilla.gnome.org/show_bug.cgi?id=752185
2015-07-10 15:25:26 +10:00

142 lines
3.4 KiB
C++

/*
* GStreamer
* Copyright (C) 2015 Matthew Waters <matthew@centricular.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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <gst/video/video.h>
#include <gst/gl/gl.h>
#include "gstqsgtexture.h"
#define GST_CAT_DEFAULT gst_qsg_texture_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
GstQSGTexture::GstQSGTexture ()
{
static volatile gsize _debug;
initializeOpenGLFunctions();
if (g_once_init_enter (&_debug)) {
GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "qtqsgtexture", 0,
"Qt Scenegraph Texture");
g_once_init_leave (&_debug, 1);
}
gst_video_info_init (&this->v_info);
this->buffer_ = NULL;
}
GstQSGTexture::~GstQSGTexture ()
{
gst_buffer_replace (&this->buffer_, NULL);
}
/* only called from the streaming thread with scene graph thread blocked */
void
GstQSGTexture::setCaps (GstCaps * caps)
{
GST_LOG ("%p setCaps %" GST_PTR_FORMAT, this, caps);
gst_video_info_from_caps (&this->v_info, caps);
}
/* only called from the streaming thread with scene graph thread blocked */
void
GstQSGTexture::setBuffer (GstBuffer * buffer)
{
GST_LOG ("%p setBuffer %" GST_PTR_FORMAT, this, buffer);
/* FIXME: update more state here */
gst_buffer_replace (&this->buffer_, buffer);
}
/* only called from qt's scene graph render thread */
void
GstQSGTexture::bind ()
{
guint tex_id;
if (!this->buffer_)
return;
if (GST_VIDEO_INFO_FORMAT (&this->v_info) == GST_VIDEO_FORMAT_UNKNOWN)
return;
/* FIXME: should really lock the memory to prevent write access */
if (!gst_video_frame_map (&this->v_frame, &this->v_info, this->buffer_,
(GstMapFlags) (GST_MAP_READ | GST_MAP_GL))) {
g_assert_not_reached ();
return;
}
tex_id = *(guint *) this->v_frame.data[0];
GST_LOG ("%p binding Qt texture %u", this, tex_id);
glBindTexture (GL_TEXTURE_2D, tex_id);
gst_video_frame_unmap (&this->v_frame);
}
/* can be called from any thread */
int
GstQSGTexture::textureId () const
{
int tex_id = 0;
if (this->buffer_) {
GstMemory *mem = gst_buffer_peek_memory (this->buffer_, 0);
tex_id = ((GstGLMemory *) mem)->tex_id;
}
GST_LOG ("%p get texture id %u", this, tex_id);
return tex_id;
}
/* can be called from any thread */
QSize
GstQSGTexture::textureSize () const
{
if (GST_VIDEO_INFO_FORMAT (&this->v_info) == GST_VIDEO_FORMAT_UNKNOWN)
return QSize (0, 0);
GST_TRACE ("%p get texture size %ux%u", this, this->v_info.width,
this->v_info.height);
return QSize (this->v_info.width, this->v_info.height);
}
/* can be called from any thread */
bool
GstQSGTexture::hasAlphaChannel () const
{
/* FIXME: support RGB textures */
return true;
}
/* can be called from any thread */
bool
GstQSGTexture::hasMipmaps () const
{
return false;
}