gstreamer/ext/qt/gstqsgtexture.cc

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/*
* 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 <vector>
#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;
this->qt_context_ = NULL;
this->sync_buffer_ = gst_buffer_new ();
this->dummy_tex_id_ = 0;
}
GstQSGTexture::~GstQSGTexture ()
{
gst_buffer_replace (&this->buffer_, NULL);
gst_buffer_replace (&this->sync_buffer_, NULL);
if (this->dummy_tex_id_ && QOpenGLContext::currentContext ()) {
QOpenGLContext::currentContext ()->functions ()->glDeleteTextures (1,
&this->dummy_tex_id_);
}
}
/* 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 */
gboolean
GstQSGTexture::setBuffer (GstBuffer * buffer)
{
GST_LOG ("%p setBuffer %" GST_PTR_FORMAT, this, buffer);
/* FIXME: update more state here */
if (!gst_buffer_replace (&this->buffer_, buffer))
return FALSE;
this->qt_context_ = gst_gl_context_get_current ();
return TRUE;
}
/* only called from qt's scene graph render thread */
void
GstQSGTexture::bind ()
{
const GstGLFuncs *gl;
GstGLContext *context;
GstGLSyncMeta *sync_meta;
GstMemory *mem;
guint tex_id;
gboolean use_dummy_tex = TRUE;
if (!this->qt_context_)
return;
gst_gl_context_activate (this->qt_context_, TRUE);
if (!this->buffer_)
goto out;
if (GST_VIDEO_INFO_FORMAT (&this->v_info) == GST_VIDEO_FORMAT_UNKNOWN)
goto out;
this->mem_ = gst_buffer_peek_memory (this->buffer_, 0);
if (!this->mem_)
goto out;
g_assert (this->qt_context_);
gl = this->qt_context_->gl_vtable;
/* 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 out;
}
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, this->qt_context_);
tex_id = *(guint *) this->v_frame.data[0];
GST_LOG ("%p binding Qt texture %u", this, tex_id);
gl->BindTexture (GL_TEXTURE_2D, tex_id);
gst_video_frame_unmap (&this->v_frame);
/* Texture was successfully bound, so we do not need
* to use the dummy texture */
use_dummy_tex = FALSE;
out:
if (G_UNLIKELY (use_dummy_tex)) {
QOpenGLContext *qglcontext = QOpenGLContext::currentContext ();
QOpenGLFunctions *funcs = qglcontext->functions ();
/* Create dummy texture if not already present.
* Use the Qt OpenGL functions instead of the GstGL ones,
* since we are using the Qt OpenGL context here, and we must
* be able to delete the texture in the destructor. */
if (this->dummy_tex_id_ == 0) {
/* 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;
std::vector < guint8 > dummy_data (tex_sidelength * tex_sidelength * 4, 0);
funcs->glGenTextures (1, &this->dummy_tex_id_);
funcs->glBindTexture (GL_TEXTURE_2D, this->dummy_tex_id_);
funcs->glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
funcs->glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
funcs->glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA, tex_sidelength,
tex_sidelength, 0, GL_RGBA, GL_UNSIGNED_BYTE, &dummy_data[0]);
}
g_assert (this->dummy_tex_id_ != 0);
funcs->glBindTexture (GL_TEXTURE_2D, this->dummy_tex_id_);
}
gst_gl_context_activate (this->qt_context_, FALSE);
}
/* 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;
}