video-sink: keep GstBuffer around until the next frame

We're working around the blitter here...

The only supported GL texture upload plugin (as far as I know) is
vaapidecode at the moment. This plugin has a fairly slow upload path :

vaapisurface -> Pixmap -> GL texture

This can take some time and the last part is currently not
synchronized. Therefore it leads to tearing. This patch tries to keep
the buffer around to prevent that but it's not perfect.

1 files changed, 28 insertions, 8 deletions

diff --git a/clutter-gst/clutter-gst-video-sink.c b/clutter-gst/clutter-gst-video-sink.c
index ed9be81..b81731c 100644
--- a/clutter-gst/clutter-gst-video-sink.c
+++ b/clutter-gst/clutter-gst-video-sink.c
@@ -1259,6 +1259,8 @@ clutter_gst_rgb32_upload (ClutterGstVideoSink *sink,
   }
 }
 
+static CoglUserDataKey gl_upload_texture_private_key;
+#define MAX_ALLOCATED_GL_TEXTURES (1)
 
 static gboolean
 clutter_gst_rgb32_upload_gl (ClutterGstVideoSink *sink,
@@ -1266,6 +1268,7 @@ clutter_gst_rgb32_upload_gl (ClutterGstVideoSink *sink,
 {
   ClutterGstVideoSinkPrivate *priv = sink->priv;
   GstVideoGLTextureUploadMeta *upload_meta;
+  gint i;
   guint gl_handle[1];
 
   //clear_frame_textures (sink);
@@ -1284,16 +1287,33 @@ clutter_gst_rgb32_upload_gl (ClutterGstVideoSink *sink,
 
   if (priv->frame[0] == NULL)
     {
-      priv->frame[0] = COGL_TEXTURE (cogl_texture_2d_new_with_size (priv->ctx,
-                                                                    priv->info.width,
-                                                                    priv->info.height));
-      cogl_texture_set_components (priv->frame[0], COGL_TEXTURE_COMPONENTS_RGBA);
-
-      if (!cogl_texture_allocate (priv->frame[0], NULL)) {
-        GST_WARNING ("Couldn't allocate cogl texture");
-        return FALSE;
+      for (i = 0; i < MAX_ALLOCATED_GL_TEXTURES; i++) {
+        priv->frame[i] = COGL_TEXTURE (cogl_texture_2d_new_with_size (priv->ctx,
+                                                                      priv->info.width,
+                                                                      priv->info.height));
+        cogl_texture_set_components (priv->frame[i], COGL_TEXTURE_COMPONENTS_RGBA);
+
+        if (!cogl_texture_allocate (priv->frame[i], NULL)) {
+          GST_WARNING ("Couldn't allocate cogl texture");
+          return FALSE;
+        }
       }
     }
+  else
+    {
+      CoglTexture *tmp;
+
+      tmp = priv->frame[0];
+      for (i = 0; i < MAX_ALLOCATED_GL_TEXTURES - 1; i++)
+        priv->frame[i] = priv->frame[i + 1];
+      priv->frame[MAX_ALLOCATED_GL_TEXTURES - 1] = tmp;
+    }
+
+  cogl_object_set_user_data (COGL_OBJECT (priv->frame[0]),
+                             &gl_upload_texture_private_key,
+                             gst_buffer_ref (buffer),
+                             (CoglUserDataDestroyCallback) gst_buffer_unref);
+
 
   if (!cogl_texture_get_gl_texture (priv->frame[0], &gl_handle[0], NULL)) {
     GST_WARNING ("Couldn't get gl texture");