qt: Fixup for dummy textures

* Initialize dummy texture Ids
* Ensure YUV->RGB matrix set for dummy textures

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6581>

subprojects/gst-plugins-good/ext/qt/gstqsgmaterial.cc

@@ -220,6 +220,7 @@ GstQSGMaterial::GstQSGMaterial ()
   this->buffer_ = NULL;
   this->buffer_was_bound = FALSE;
   this->sync_buffer_ = gst_buffer_new ();
+  memset (&this->dummy_textures, 0, sizeof (this->dummy_textures));
 }
 
 GstQSGMaterial::~GstQSGMaterial ()
@@ -338,6 +339,32 @@ GstQSGMaterial::createShader() const
   return new GstQSGMaterialShader(v_format, vertex, fragment);
 }
 
+void
+GstQSGMaterial::initYuvShaders (GstQSGMaterialShader *shader,
+    const GstVideoColorimetry *cinfo)
+{
+  g_return_if_fail (shader);
+
+  if (cinfo && gst_video_colorimetry_matches (cinfo,
+          GST_VIDEO_COLORIMETRY_BT709)) {
+    this->cms_offset = (gfloat *) from_yuv_bt709_offset;
+    this->cms_ycoeff = (gfloat *) from_yuv_bt709_rcoeff;
+    this->cms_ucoeff = (gfloat *) from_yuv_bt709_gcoeff;
+    this->cms_vcoeff = (gfloat *) from_yuv_bt709_bcoeff;
+  } else {
+    /* defaults/bt601 */
+    this->cms_offset = (gfloat *) from_yuv_bt601_offset;
+    this->cms_ycoeff = (gfloat *) from_yuv_bt601_rcoeff;
+    this->cms_ucoeff = (gfloat *) from_yuv_bt601_gcoeff;
+    this->cms_vcoeff = (gfloat *) from_yuv_bt601_bcoeff;
+  }
+
+  shader->program()->setUniformValue(shader->cms_uniform_offset, QVector3D(this->cms_offset[0], this->cms_offset[1], this->cms_offset[2]));
+  shader->program()->setUniformValue(shader->cms_uniform_ycoeff, QVector3D(this->cms_ycoeff[0], this->cms_ycoeff[1], this->cms_ycoeff[2]));
+  shader->program()->setUniformValue(shader->cms_uniform_ucoeff, QVector3D(this->cms_ucoeff[0], this->cms_ucoeff[1], this->cms_ucoeff[2]));
+  shader->program()->setUniformValue(shader->cms_uniform_vcoeff, QVector3D(this->cms_vcoeff[0], this->cms_vcoeff[1], this->cms_vcoeff[2]));
+}
+
 /* only called from the streaming thread with scene graph thread blocked */
 void
 GstQSGMaterial::setCaps (GstCaps * caps)
@@ -426,28 +453,10 @@ GstQSGMaterial::bind(GstQSGMaterialShader *shader, GstVideoFormat v_format)
 
   gst_gl_sync_meta_wait (sync_meta, qt_context);
 
-  if (this->v_frame.info.finfo->flags & GST_VIDEO_FORMAT_FLAG_YUV) {
+  if (this->v_frame.info.finfo->flags & GST_VIDEO_FORMAT_FLAG_YUV)
-    if (gst_video_colorimetry_matches (&this->v_frame.info.colorimetry,
+    initYuvShaders (shader, &this->v_frame.info.colorimetry);
-            GST_VIDEO_COLORIMETRY_BT709)) {
+  else
-      this->cms_offset = (gfloat *) from_yuv_bt709_offset;
-      this->cms_ycoeff = (gfloat *) from_yuv_bt709_rcoeff;
-      this->cms_ucoeff = (gfloat *) from_yuv_bt709_gcoeff;
-      this->cms_vcoeff = (gfloat *) from_yuv_bt709_bcoeff;
-    } else {
-      /* defaults/bt601 */
-      this->cms_offset = (gfloat *) from_yuv_bt601_offset;
-      this->cms_ycoeff = (gfloat *) from_yuv_bt601_rcoeff;
-      this->cms_ucoeff = (gfloat *) from_yuv_bt601_gcoeff;
-      this->cms_vcoeff = (gfloat *) from_yuv_bt601_bcoeff;
-    }
-
-    shader->program()->setUniformValue(shader->cms_uniform_offset, QVector3D(this->cms_offset[0], this->cms_offset[1], this->cms_offset[2]));
-    shader->program()->setUniformValue(shader->cms_uniform_ycoeff, QVector3D(this->cms_ycoeff[0], this->cms_ycoeff[1], this->cms_ycoeff[2]));
-    shader->program()->setUniformValue(shader->cms_uniform_ucoeff, QVector3D(this->cms_ucoeff[0], this->cms_ucoeff[1], this->cms_ucoeff[2]));
-    shader->program()->setUniformValue(shader->cms_uniform_vcoeff, QVector3D(this->cms_vcoeff[0], this->cms_vcoeff[1], this->cms_vcoeff[2]));
-  } else {
     this->cms_offset = this->cms_ycoeff = this->cms_ucoeff = this->cms_vcoeff = NULL;
-  }
 
   /* reversed iteration order so that glActiveTexture(GL_TEXTURE0) is last which keeps
    * us in the default GL state expected by several other qml components
@@ -475,6 +484,9 @@ out:
     QOpenGLFunctions *funcs = qglcontext->functions ();
     const GstVideoFormatInfo *finfo = gst_video_format_get_info (v_format);
 
+    if (finfo->flags == GST_VIDEO_FORMAT_FLAG_YUV)
+      initYuvShaders (shader, nullptr);
+
     /* 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
@@ -492,14 +504,20 @@ out:
         const int tex_sidelength = 64;
 
         std::vector < guint8 > dummy_data (tex_sidelength * tex_sidelength * 4, 0);
+        guint8 *data = dummy_data.data();
+
         switch (v_format) {
           case GST_VIDEO_FORMAT_RGBA:
           case GST_VIDEO_FORMAT_BGRA:
           case GST_VIDEO_FORMAT_RGB:
+            for (gsize j = 0; j < tex_sidelength; j++) {
+              for (gsize k = 0; k < tex_sidelength; k++) {
+                data[(j * tex_sidelength + k) * 4 + 3] = 0xFF; // opaque
+              }
+            }
             break;
           case GST_VIDEO_FORMAT_YV12:
             if (i == 1 || i == 2) {
-              guint8 *data = dummy_data.data();
               for (gsize j = 0; j < tex_sidelength; j++) {
                 for (gsize k = 0; k < tex_sidelength; k++) {
                   data[(j * tex_sidelength + k) * 4 + 0] = 0x7F;
@@ -517,7 +535,7 @@ out:
         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]);
+            tex_sidelength, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
       }
 
       g_assert (this->dummy_textures[i] != 0);

subprojects/gst-plugins-good/ext/qt/gstqsgmaterial.h

@@ -52,6 +52,9 @@ public:
     QSGMaterialShader *createShader() const override;
 
 private:
+    void initYuvShaders(GstQSGMaterialShader *shader,
+        const GstVideoColorimetry *cinfo);
+
     GstBuffer * buffer_;
     gboolean buffer_was_bound;
     GstBuffer * sync_buffer_;