gstreamer/subprojects/gst-plugins-good/ext/qt6/gstqsg6glnode.cc
Matthew Waters 18972fc942 add new plugin for Qt 6 rendering inside a QML scene
- Based heavily on the existing Qt5 integration however:
  - The sharing of OpenGL resources is slightly different
  - The integration with the scengraph is a bit different
- Wayland, XCB and KMS have been smoke tested.  Android, MacOS/iOS,
  Windows may or may not work.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3281>
2022-11-24 16:11:04 +11:00

186 lines
5.6 KiB
C++

/*
* GStreamer
* Copyright (C) 2022 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.
*/
#include "gstqsg6glnode.h"
#include <QtQuick/QSGTextureProvider>
#include <QtQuick/QSGSimpleTextureNode>
#include <QtQuick/QQuickWindow>
#include <QtQuick/QSGTexture>
#define GST_CAT_DEFAULT gst_qsg_texture_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
GstQSG6OpenGLNode::GstQSG6OpenGLNode(QQuickItem * item)
{
static gsize _debug;
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;
this->sync_buffer_ = gst_buffer_new ();
this->dummy_tex_ = nullptr;
// TODO; handle windowChanged?
this->window_ = item->window();
}
GstQSG6OpenGLNode::~GstQSG6OpenGLNode()
{
gst_buffer_replace (&this->buffer_, NULL);
gst_buffer_replace (&this->sync_buffer_, NULL);
this->buffer_was_bound = FALSE;
delete this->dummy_tex_;
this->dummy_tex_ = nullptr;
}
QSGTexture *
GstQSG6OpenGLNode::texture() const
{
return QSGSimpleTextureNode::texture();
}
/* only called from the streaming thread with scene graph thread blocked */
void
GstQSG6OpenGLNode::setCaps (GstCaps * caps)
{
GST_LOG ("%p setCaps %" GST_PTR_FORMAT, this, caps);
if (caps)
gst_video_info_from_caps (&this->v_info, caps);
else
gst_video_info_init (&this->v_info);
}
/* only called from the streaming thread with scene graph thread blocked */
GstBuffer *
GstQSG6OpenGLNode::getBuffer ()
{
GstBuffer *buffer = NULL;
if (this->buffer_)
buffer = gst_buffer_ref (this->buffer_);
return buffer;
}
/* only called from the streaming thread with scene graph thread blocked */
void
GstQSG6OpenGLNode::setBuffer (GstBuffer * buffer)
{
GstGLContext *qt_context = NULL;
gboolean buffer_changed;
GST_LOG ("%p setBuffer %" GST_PTR_FORMAT, this, buffer);
/* FIXME: update more state here */
buffer_changed = gst_buffer_replace (&this->buffer_, buffer);
if (buffer_changed) {
GstGLContext *context;
GstGLSyncMeta *sync_meta;
GstMemory *mem;
guint tex_id;
QQuickWindow::CreateTextureOptions options = QQuickWindow::TextureHasAlphaChannel;
QSGTexture *texture = nullptr;
QSize texSize;
qt_context = gst_gl_context_get_current();
if (!qt_context)
goto use_dummy_tex;
if (!this->buffer_)
goto use_dummy_tex;
if (GST_VIDEO_INFO_FORMAT (&this->v_info) == GST_VIDEO_FORMAT_UNKNOWN)
goto use_dummy_tex;
this->mem_ = gst_buffer_peek_memory (this->buffer_, 0);
if (!this->mem_)
goto use_dummy_tex;
/* 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 ();
goto use_dummy_tex;
}
mem = gst_buffer_peek_memory (this->buffer_, 0);
g_assert (gst_is_gl_memory (mem));
context = ((GstGLBaseMemory *)mem)->context;
sync_meta = gst_buffer_get_gl_sync_meta (this->sync_buffer_);
if (!sync_meta)
sync_meta = gst_buffer_add_gl_sync_meta (context, this->sync_buffer_);
gst_gl_sync_meta_set_sync_point (sync_meta, context);
gst_gl_sync_meta_wait (sync_meta, qt_context);
tex_id = *(guint *) this->v_frame.data[0];
GST_LOG ("%p binding Qt texture %u", this, tex_id);
texSize = QSize(GST_VIDEO_FRAME_WIDTH (&this->v_frame), GST_VIDEO_FRAME_HEIGHT (&this->v_frame));
// XXX: ideally, we would like to subclass the relevant texture object
// ourselves but this is good enough for now
texture = QNativeInterface::QSGOpenGLTexture::fromNative(tex_id, this->window_, texSize, options);
setTexture(texture);
setOwnsTexture(true);
markDirty(QSGNode::DirtyMaterial);
gst_video_frame_unmap (&this->v_frame);
/* Texture was successfully bound, so we do not need
* to use the dummy texture */
}
if (!texture()) {
use_dummy_tex:
/* Create dummy texture if not already present. */
if (this->dummy_tex_ == nullptr) {
/* Make this a black 64x64 pixel RGBA texture.
* This size and format is supported pretty much everywhere, so these
* are a safe pick. (64 pixel sidelength must be supported according
* to the GLES2 spec, table 6.18.)
* Set min/mag filters to GL_LINEAR to make sure no mipmapping is used. */
const int tex_sidelength = 64;
QImage image(tex_sidelength, tex_sidelength, QImage::Format_ARGB32);
image.fill(QColor(0, 0, 0, 255));
this->dummy_tex_ = this->window_->createTextureFromImage(image);
}
g_assert (this->dummy_tex_ != nullptr);
if (texture() != this->dummy_tex_) {
setTexture(this->dummy_tex_);
setOwnsTexture(false);
markDirty(QSGNode::DirtyMaterial);
}
GST_LOG ("%p binding fallback dummy Qt texture %p", this, this->dummy_tex_);
}
}