/*
* GStreamer
* Copyright (C) 2013 Matthew Waters <ystreet00@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:gstglutils
* @title: GstGLUtils
* @short_description: some miscellaneous utilities for OpenGL
* @see_also: #GstGLContext
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <gst/gst.h>
#include <glib/gprintf.h>
#include "gl.h"
#include "gstglutils.h"
#include "gstglutils_private.h"
#if GST_GL_HAVE_WINDOW_X11
#include <gst/gl/x11/gstgldisplay_x11.h>
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
#include <gst/gl/wayland/gstgldisplay_wayland.h>
#endif
#define USING_OPENGL(context) (gst_gl_context_check_gl_version (context, GST_GL_API_OPENGL, 1, 0))
#define USING_OPENGL3(context) (gst_gl_context_check_gl_version (context, GST_GL_API_OPENGL3, 3, 1))
#define USING_GLES(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES, 1, 0))
#define USING_GLES2(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 2, 0))
#define USING_GLES3(context) (gst_gl_context_check_gl_version (context, GST_GL_API_GLES2, 3, 0))
#ifndef GST_DISABLE_GST_DEBUG
GST_DEBUG_CATEGORY_STATIC (gst_gl_utils_debug);
static GstDebugCategory *
_init_gl_utils_debug_category (void)
{
static volatile gsize _init = 0;
if (g_once_init_enter (&_init)) {
GST_DEBUG_CATEGORY_INIT (gst_gl_utils_debug, "glutils", 0,
"OpenGL Utilities");
g_once_init_leave (&_init, 1);
}
return gst_gl_utils_debug;
}
#define GST_CAT_DEFAULT _init_gl_utils_debug_category()
#endif
static gboolean
gst_gl_display_found (GstElement * element, GstGLDisplay * display)
{
if (display) {
GST_LOG_OBJECT (element, "already have a display (%p)", display);
return TRUE;
}
return FALSE;
}
GST_DEBUG_CATEGORY_STATIC (GST_CAT_CONTEXT);
static void
_init_context_debug (void)
{
#ifndef GST_DISABLE_GST_DEBUG
static volatile gsize _init = 0;
if (g_once_init_enter (&_init)) {
GST_DEBUG_CATEGORY_GET (GST_CAT_CONTEXT, "GST_CONTEXT");
g_once_init_leave (&_init, 1);
}
#endif
}
static gboolean
pad_query (const GValue * item, GValue * value, gpointer user_data)
{
GstPad *pad = g_value_get_object (item);
GstQuery *query = user_data;
gboolean res;
_init_context_debug ();
res = gst_pad_peer_query (pad, query);
if (res) {
g_value_set_boolean (value, TRUE);
return FALSE;
}
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, pad, "pad peer query failed");
return TRUE;
}
gboolean
gst_gl_run_query (GstElement * element, GstQuery * query,
GstPadDirection direction)
{
GstIterator *it;
GstIteratorFoldFunction func = pad_query;
GValue res = { 0 };
g_value_init (&res, G_TYPE_BOOLEAN);
g_value_set_boolean (&res, FALSE);
/* Ask neighbor */
if (direction == GST_PAD_SRC)
it = gst_element_iterate_src_pads (element);
else
it = gst_element_iterate_sink_pads (element);
while (gst_iterator_fold (it, func, &res, query) == GST_ITERATOR_RESYNC)
gst_iterator_resync (it);
gst_iterator_free (it);
return g_value_get_boolean (&res);
}
static void
_gst_context_query (GstElement * element, const gchar * display_type)
{
GstQuery *query;
GstContext *ctxt;
_init_context_debug ();
/* 2a) Query downstream with GST_QUERY_CONTEXT for the context and
* check if downstream already has a context of the specific type
* 2b) Query upstream as above.
*/
query = gst_query_new_context (display_type);
if (gst_gl_run_query (element, query, GST_PAD_SRC)) {
gst_query_parse_context (query, &ctxt);
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"found context (%p) in downstream query", ctxt);
gst_element_set_context (element, ctxt);
} else if (gst_gl_run_query (element, query, GST_PAD_SINK)) {
gst_query_parse_context (query, &ctxt);
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"found context (%p) in upstream query", ctxt);
gst_element_set_context (element, ctxt);
} else {
/* 3) Post a GST_MESSAGE_NEED_CONTEXT message on the bus with
* the required context type and afterwards check if a
* usable context was set now as in 1). The message could
* be handled by the parent bins of the element and the
* application.
*/
GstMessage *msg;
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"posting need context message");
msg = gst_message_new_need_context (GST_OBJECT_CAST (element),
display_type);
gst_element_post_message (element, msg);
}
/*
* Whomever responds to the need-context message performs a
* GstElement::set_context() with the required context in which the element
* is required to update the display_ptr or call gst_gl_handle_set_context().
*/
gst_query_unref (query);
}
static void
gst_gl_display_context_query (GstElement * element, GstGLDisplay ** display_ptr)
{
_gst_context_query (element, GST_GL_DISPLAY_CONTEXT_TYPE);
if (*display_ptr)
return;
#if GST_GL_HAVE_WINDOW_X11
_gst_context_query (element, "gst.x11.display.handle");
if (*display_ptr)
return;
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
_gst_context_query (element, "GstWaylandDisplayHandleContextType");
if (*display_ptr)
return;
#endif
}
static void
gst_gl_context_query (GstElement * element)
{
_gst_context_query (element, "gst.gl.app_context");
}
/* 4) Create a context by itself and post a GST_MESSAGE_HAVE_CONTEXT
* message.
*/
void
gst_gl_element_propagate_display_context (GstElement * element,
GstGLDisplay * display)
{
GstContext *context;
GstMessage *msg;
if (!display) {
GST_ERROR_OBJECT (element, "Could not get GL display connection");
return;
}
_init_context_debug ();
context = gst_context_new (GST_GL_DISPLAY_CONTEXT_TYPE, TRUE);
gst_context_set_gl_display (context, display);
gst_element_set_context (element, context);
GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
"posting have context (%p) message with display (%p)", context, display);
msg = gst_message_new_have_context (GST_OBJECT_CAST (element), context);
gst_element_post_message (GST_ELEMENT_CAST (element), msg);
}
/**
* gst_gl_ensure_element_data:
* @element: the #GstElement running the query
* @display_ptr: (inout): the resulting #GstGLDisplay
* @other_context_ptr: (inout): the resulting #GstGLContext
*
* Perform the steps necessary for retrieving a #GstGLDisplay and (optionally)
* an application provided #GstGLContext from the surrounding elements or from
* the application using the #GstContext mechanism.
*
* If the contents of @display_ptr or @other_context_ptr are not %NULL, then no
* #GstContext query is necessary for #GstGLDisplay or #GstGLContext retrieval
* or is performed.
*
* This performs #GstContext queries (if necessary) for a winsys display
* connection with %GST_GL_DISPLAY_CONTEXT_TYPE, "gst.x11.display.handle", and
* "GstWaylandDisplayHandleContextType" stopping after the first successful
* retrieval.
*
* This also performs a #GstContext query (if necessary) for an optional
* application provided #GstGLContext using the name "gst.gl.app_context".
* The returned #GstGLContext will be shared with a GStreamer created OpenGL context.
*
* Returns: whether a #GstGLDisplay exists in @display_ptr
*/
gboolean
gst_gl_ensure_element_data (gpointer element, GstGLDisplay ** display_ptr,
GstGLContext ** other_context_ptr)
{
GstGLDisplay *display;
g_return_val_if_fail (element != NULL, FALSE);
g_return_val_if_fail (display_ptr != NULL, FALSE);
g_return_val_if_fail (other_context_ptr != NULL, FALSE);
/* 1) Check if the element already has a context of the specific
* type.
*/
display = *display_ptr;
if (gst_gl_display_found (element, display))
goto done;
gst_gl_display_context_query (element, display_ptr);
/* Neighbour found and it updated the display */
if (gst_gl_display_found (element, *display_ptr))
goto get_gl_context;
/* If no neighboor, or application not interested, use system default */
display = gst_gl_display_new ();
*display_ptr = display;
gst_gl_element_propagate_display_context (element, display);
get_gl_context:
if (*other_context_ptr)
goto done;
gst_gl_context_query (element);
done:
return *display_ptr != NULL;
}
/**
* gst_gl_handle_set_context:
* @element: a #GstElement
* @context: a #GstContext
* @display: (inout) (transfer full): location of a #GstGLDisplay
* @other_context: (inout) (transfer full): location of a #GstGLContext
*
* Helper function for implementing GstElement::set_context() in OpenGL capable
* elements.
*
* Retrieve's the #GstGLDisplay or #GstGLContext in @context and places the
* result in @display or @other_context respectively.
*
* Returns: whether the @display or @other_context could be set successfully
*/
gboolean
gst_gl_handle_set_context (GstElement * element, GstContext * context,
GstGLDisplay ** display, GstGLContext ** other_context)
{
GstGLDisplay *display_replacement = NULL;
GstGLContext *context_replacement = NULL;
const gchar *context_type;
g_return_val_if_fail (display != NULL, FALSE);
g_return_val_if_fail (other_context != NULL, FALSE);
if (!context)
return FALSE;
context_type = gst_context_get_context_type (context);
if (g_strcmp0 (context_type, GST_GL_DISPLAY_CONTEXT_TYPE) == 0) {
if (!gst_context_get_gl_display (context, &display_replacement)) {
GST_WARNING_OBJECT (element, "Failed to get display from context");
return FALSE;
}
}
#if GST_GL_HAVE_WINDOW_X11
else if (g_strcmp0 (context_type, "gst.x11.display.handle") == 0) {
const GstStructure *s;
Display *display;
s = gst_context_get_structure (context);
if (gst_structure_get (s, "display", G_TYPE_POINTER, &display, NULL))
display_replacement =
(GstGLDisplay *) gst_gl_display_x11_new_with_display (display);
}
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
else if (g_strcmp0 (context_type, "GstWaylandDisplayHandleContextType") == 0) {
const GstStructure *s;
struct wl_display *display;
s = gst_context_get_structure (context);
if (gst_structure_get (s, "display", G_TYPE_POINTER, &display, NULL))
display_replacement =
(GstGLDisplay *) gst_gl_display_wayland_new_with_display (display);
}
#endif
else if (g_strcmp0 (context_type, "gst.gl.app_context") == 0) {
const GstStructure *s = gst_context_get_structure (context);
GstGLDisplay *context_display;
GstGLDisplay *element_display;
if (gst_structure_get (s, "context", GST_TYPE_GL_CONTEXT,
&context_replacement, NULL)) {
context_display = gst_gl_context_get_display (context_replacement);
element_display = display_replacement ? display_replacement : *display;
if (element_display
&& (gst_gl_display_get_handle_type (element_display) &
gst_gl_display_get_handle_type (context_display)) == 0) {
GST_ELEMENT_WARNING (element, LIBRARY, SETTINGS, ("%s",
"Cannot set a GL context with a different display type"), ("%s",
"Cannot set a GL context with a different display type"));
gst_object_unref (context_replacement);
context_replacement = NULL;
}
gst_object_unref (context_display);
}
}
if (display_replacement) {
GstGLDisplay *old = *display;
*display = display_replacement;
if (old)
gst_object_unref (old);
}
if (context_replacement) {
GstGLContext *old = *other_context;
*other_context = context_replacement;
if (old)
gst_object_unref (old);
}
return TRUE;
}
/**
* gst_gl_handle_context_query:
* @element: a #GstElement
* @query: a #GstQuery of type %GST_QUERY_CONTEXT
* @display: (transfer none) (nullable): a #GstGLDisplay
* @context: (transfer none) (nullable): a #GstGLContext
* @other_context: (transfer none) (nullable): application provided #GstGLContext
*
* Returns: Whether the @query was successfully responded to from the passed
* @display, @context, and @other_context.
*/
gboolean
gst_gl_handle_context_query (GstElement * element, GstQuery * query,
GstGLDisplay * display, GstGLContext * gl_context,
GstGLContext * other_context)
{
const gchar *context_type;
GstContext *context, *old_context;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (GST_IS_QUERY (query), FALSE);
g_return_val_if_fail (display == NULL || GST_IS_GL_DISPLAY (display), FALSE);
g_return_val_if_fail (gl_context == NULL
|| GST_IS_GL_CONTEXT (gl_context), FALSE);
g_return_val_if_fail (other_context == NULL
|| GST_IS_GL_CONTEXT (other_context), FALSE);
GST_LOG_OBJECT (element, "handle context query %" GST_PTR_FORMAT, query);
gst_query_parse_context_type (query, &context_type);
if (display && g_strcmp0 (context_type, GST_GL_DISPLAY_CONTEXT_TYPE) == 0) {
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new (GST_GL_DISPLAY_CONTEXT_TYPE, TRUE);
gst_context_set_gl_display (context, display);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set %" GST_PTR_FORMAT
" on %" GST_PTR_FORMAT, display, query);
return TRUE;
}
#if GST_GL_HAVE_WINDOW_X11
else if (display && g_strcmp0 (context_type, "gst.x11.display.handle") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.x11.display.handle", TRUE);
if (gst_gl_display_get_handle_type (display) & GST_GL_DISPLAY_TYPE_X11) {
Display *x11_display = (Display *) gst_gl_display_get_handle (display);
if (x11_display) {
s = gst_context_writable_structure (context);
gst_structure_set (s, "display", G_TYPE_POINTER, x11_display, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set x11 display %p (from %"
GST_PTR_FORMAT ") on %" GST_PTR_FORMAT, x11_display, display,
query);
return TRUE;
}
}
}
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
else if (display
&& g_strcmp0 (context_type, "GstWaylandDisplayHandleContextType") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("GstWaylandDisplayHandleContextType", TRUE);
if (gst_gl_display_get_handle_type (display) & GST_GL_DISPLAY_TYPE_WAYLAND) {
struct wl_display *wayland_display =
(struct wl_display *) gst_gl_display_get_handle (display);
if (wayland_display) {
s = gst_context_writable_structure (context);
gst_structure_set (s, "display", G_TYPE_POINTER, wayland_display, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set wayland display %p (from %"
GST_PTR_FORMAT ") on %" GST_PTR_FORMAT, wayland_display, display,
query);
return TRUE;
}
}
}
#endif
else if (other_context && g_strcmp0 (context_type, "gst.gl.app_context") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.gl.app_context", TRUE);
s = gst_context_writable_structure (context);
gst_structure_set (s, "context", GST_TYPE_GL_CONTEXT, other_context, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set application GL context %"
GST_PTR_FORMAT " on %" GST_PTR_FORMAT, other_context, query);
return TRUE;
} else if (gl_context
&& g_strcmp0 (context_type, "gst.gl.local_context") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.gl.local_context", TRUE);
s = gst_context_writable_structure (context);
gst_structure_set (s, "context", GST_TYPE_GL_CONTEXT, gl_context, NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
GST_DEBUG_OBJECT (element, "successfully set GL context %"
GST_PTR_FORMAT " on %" GST_PTR_FORMAT, gl_context, query);
return TRUE;
}
return FALSE;
}
/**
* gst_gl_query_local_gl_context:
* @element: a #GstElement to query from
* @direction: the #GstPadDirection to query
* @context_ptr: (inout): location containing the current and/or resulting
* #GstGLContext
*
* Performs a GST_QUERY_CONTEXT query of type "gst.gl.local_context" on all
* #GstPads in @element of @direction for the local OpenGL context used by
* GStreamer elements.
*
* Returns: whether @context_ptr contains a #GstGLContext
*/
gboolean
gst_gl_query_local_gl_context (GstElement * element, GstPadDirection direction,
GstGLContext ** context_ptr)
{
GstQuery *query;
GstContext *context;
const GstStructure *s;
g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
g_return_val_if_fail (context_ptr != NULL, FALSE);
if (*context_ptr)
return TRUE;
query = gst_query_new_context ("gst.gl.local_context");
if (gst_gl_run_query (GST_ELEMENT (element), query, direction)) {
gst_query_parse_context (query, &context);
if (context) {
s = gst_context_get_structure (context);
gst_structure_get (s, "context", GST_TYPE_GL_CONTEXT, context_ptr, NULL);
}
}
gst_query_unref (query);
return *context_ptr != NULL;
}
/**
* gst_gl_get_plane_data_size:
* @info: a #GstVideoInfo
* @align: a #GstVideoAlignment or %NULL
* @plane: plane number in @info to retrieve the data size of
*
* Retrieve the size in bytes of a video plane of data with a certain alignment
*/
gsize
gst_gl_get_plane_data_size (GstVideoInfo * info, GstVideoAlignment * align,
guint plane)
{
gint padded_height;
gsize plane_size;
padded_height = info->height;
if (align)
padded_height += align->padding_top + align->padding_bottom;
padded_height =
GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (info->finfo, plane, padded_height);
plane_size = GST_VIDEO_INFO_PLANE_STRIDE (info, plane) * padded_height;
return plane_size;
}
/**
* gst_gl_get_plane_start:
* @info: a #GstVideoInfo
* @valign: a #GstVideoAlignment or %NULL
* @plane: plane number in @info to retrieve the data size of
*
* Returns: difference between the supposed start of the plane from the @info
* and where the data from the previous plane ends.
*/
gsize
gst_gl_get_plane_start (GstVideoInfo * info, GstVideoAlignment * valign,
guint plane)
{
gsize plane_start;
gint i;
/* find the start of the plane data including padding */
plane_start = 0;
for (i = 0; i < plane; i++) {
plane_start += gst_gl_get_plane_data_size (info, valign, i);
}
/* offset between the plane data start and where the video frame starts */
return (GST_VIDEO_INFO_PLANE_OFFSET (info, plane)) - plane_start;
}
/**
* gst_gl_value_get_texture_target_mask:
* @value: an initialized #GValue of type G_TYPE_STRING
*
* See gst_gl_value_set_texture_target_from_mask() for what entails a mask
*
* Returns: the mask of #GstGLTextureTarget's in @value
*/
GstGLTextureTarget
gst_gl_value_get_texture_target_mask (const GValue * targets)
{
guint new_targets = 0;
g_return_val_if_fail (targets != NULL, GST_GL_TEXTURE_TARGET_NONE);
if (G_TYPE_CHECK_VALUE_TYPE (targets, G_TYPE_STRING)) {
GstGLTextureTarget target;
const gchar *str;
str = g_value_get_string (targets);
target = gst_gl_texture_target_from_string (str);
if (target)
new_targets |= 1 << target;
} else if (G_TYPE_CHECK_VALUE_TYPE (targets, GST_TYPE_LIST)) {
gint j, m;
m = gst_value_list_get_size (targets);
for (j = 0; j < m; j++) {
const GValue *val = gst_value_list_get_value (targets, j);
GstGLTextureTarget target;
const gchar *str;
str = g_value_get_string (val);
target = gst_gl_texture_target_from_string (str);
if (target)
new_targets |= 1 << target;
}
}
return new_targets;
}
/**
* gst_gl_value_set_texture_target:
* @value: an initialized #GValue of type G_TYPE_STRING
* @target: a #GstGLTextureTarget's
*
* Returns: whether the @target could be set on @value
*/
gboolean
gst_gl_value_set_texture_target (GValue * value, GstGLTextureTarget target)
{
g_return_val_if_fail (value != NULL, FALSE);
g_return_val_if_fail (target != GST_GL_TEXTURE_TARGET_NONE, FALSE);
if (target == GST_GL_TEXTURE_TARGET_2D) {
g_value_set_static_string (value, GST_GL_TEXTURE_TARGET_2D_STR);
} else if (target == GST_GL_TEXTURE_TARGET_RECTANGLE) {
g_value_set_static_string (value, GST_GL_TEXTURE_TARGET_RECTANGLE_STR);
} else if (target == GST_GL_TEXTURE_TARGET_EXTERNAL_OES) {
g_value_set_static_string (value, GST_GL_TEXTURE_TARGET_EXTERNAL_OES_STR);
} else {
return FALSE;
}
return TRUE;
}
static guint64
_gst_gl_log2_int64 (guint64 value)
{
guint64 ret = 0;
while (value >>= 1)
ret++;
return ret;
}
/**
* gst_gl_value_set_texture_target_from_mask:
* @value: an uninitialized #GValue
* @target_mask: a bitwise mask of #GstGLTextureTarget's
*
* A mask is a bitwise OR of (1 << target) where target is a valid
* #GstGLTextureTarget
*
* Returns: whether the @target_mask could be set on @value
*/
gboolean
gst_gl_value_set_texture_target_from_mask (GValue * value,
GstGLTextureTarget target_mask)
{
g_return_val_if_fail (value != NULL, FALSE);
g_return_val_if_fail (target_mask != GST_GL_TEXTURE_TARGET_NONE, FALSE);
if ((target_mask & (target_mask - 1)) == 0) {
/* only one texture target set */
g_value_init (value, G_TYPE_STRING);
return gst_gl_value_set_texture_target (value,
_gst_gl_log2_int64 (target_mask));
} else {
GValue item = G_VALUE_INIT;
gboolean ret = FALSE;
g_value_init (value, GST_TYPE_LIST);
g_value_init (&item, G_TYPE_STRING);
if (target_mask & (1 << GST_GL_TEXTURE_TARGET_2D)) {
gst_gl_value_set_texture_target (&item, GST_GL_TEXTURE_TARGET_2D);
gst_value_list_append_value (value, &item);
ret = TRUE;
}
if (target_mask & (1 << GST_GL_TEXTURE_TARGET_RECTANGLE)) {
gst_gl_value_set_texture_target (&item, GST_GL_TEXTURE_TARGET_RECTANGLE);
gst_value_list_append_value (value, &item);
ret = TRUE;
}
if (target_mask & (1 << GST_GL_TEXTURE_TARGET_EXTERNAL_OES)) {
gst_gl_value_set_texture_target (&item,
GST_GL_TEXTURE_TARGET_EXTERNAL_OES);
gst_value_list_append_value (value, &item);
ret = TRUE;
}
g_value_unset (&item);
return ret;
}
}
static const gfloat identity_matrix[] = {
1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0,
};
static const gfloat from_ndc_matrix[] = {
0.5, 0.0, 0.0, 0.0,
0.0, 0.5, 0.0, 0.0,
0.0, 0.0, 0.5, 0.0,
0.5, 0.5, 0.5, 1.0,
};
static const gfloat to_ndc_matrix[] = {
2.0, 0.0, 0.0, 0.0,
0.0, 2.0, 0.0, 0.0,
0.0, 0.0, 2.0, 0.0,
-1.0, -1.0, -1.0, 1.0,
};
/* multiplies two 4x4 matrices, @a X @b, and stores the result in @result
* https://en.wikipedia.org/wiki/Matrix_multiplication
*/
static void
gst_gl_multiply_matrix4 (const gfloat * a, const gfloat * b, gfloat * result)
{
int i, j, k;
gfloat tmp[16] = { 0.0f };
if (!a || !b || !result)
return;
for (i = 0; i < 4; i++) { /* column */
for (j = 0; j < 4; j++) { /* row */
for (k = 0; k < 4; k++) {
tmp[j + (i * 4)] += a[k + (i * 4)] * b[j + (k * 4)];
}
}
}
for (i = 0; i < 16; i++)
result[i] = tmp[i];
}
/*
* gst_gl_get_affine_transformation_meta_as_ndc:
* @meta: (nullable): a #GstVideoAffineTransformationMeta
* @matrix: (out): result of the 4x4 matrix
*
* Retrieves the stored 4x4 affine transformation matrix stored in @meta in
* NDC coordinates. if @meta is NULL, an identity matrix is returned.
*
* NDC is a left-handed coordinate sytem
* - x - [-1, 1] - +ve X moves right
* - y - [-1, 1] - +ve Y moves up
* - z - [-1, 1] - +ve Z moves into
*/
void
gst_gl_get_affine_transformation_meta_as_ndc (GstVideoAffineTransformationMeta *
meta, gfloat * matrix)
{
if (!meta) {
int i;
for (i = 0; i < 16; i++) {
matrix[i] = identity_matrix[i];
}
} else {
float tmp[16];
/* change of basis multiplications */
gst_gl_multiply_matrix4 (to_ndc_matrix, meta->matrix, tmp);
gst_gl_multiply_matrix4 (tmp, from_ndc_matrix, matrix);
}
}
void gst_gl_set_affine_transformation_meta_from_ndc
(GstVideoAffineTransformationMeta * meta, const gfloat * matrix)
{
float tmp[16];
g_return_if_fail (meta != NULL);
/* change of basis multiplications */
gst_gl_multiply_matrix4 (from_ndc_matrix, matrix, tmp);
gst_gl_multiply_matrix4 (tmp, to_ndc_matrix, meta->matrix);
}