sink: Support rendering external-oes textures

This significantly improves performance on mobile devices by removing the texture copy from an OES texture to 2D texture.
2025-08-30 16:02:00 +02:00 · 2021-07-02 18:24:59 +02:00
parent 2eea3b05b1
commit 2e776ddf7b
6 changed files with 303 additions and 30 deletions
--- a/lib/gst/clapper/gtk4/gstclapperglutils.c
+++ b/lib/gst/clapper/gtk4/gstclapperglutils.c
@@ -0,0 +1,103 @@
+/*
+ * GStreamer
+ * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
+ * Copyright (C) 2015 Thibault Saunier <tsaunier@gnome.org>
+ * Copyright (C) 2021 Rafał Dzięgiel <rafostar.github@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.
+ */
+
+/* FIXME: remove these once their headers are public in gstreamer:
+ * https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/804
+ */
+
+#include "gstclapperglutils.h"
+
+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_clapper_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 system
+ * - x - [-1, 1] - +ve X moves right
+ * - y - [-1, 1] - +ve Y moves up
+ * - z - [-1, 1] - +ve Z moves into
+ */
+void
+gst_clapper_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 (from_ndc_matrix, meta->matrix, tmp);
+    gst_gl_multiply_matrix4 (tmp, to_ndc_matrix, matrix);
+  }
+}