gldownload: Refactor download mode selection

This introduces an enum in order to cleanup how we select the
transfer mode. It also fixes the case where we callback to PBO but
we didn't execute the PBO. That was not causing any issue, just that
the processing latency would be delayed to the next element, which
can be confusing.

diff --git a/ext/gl/gstgldownloadelement.c b/ext/gl/gstgldownloadelement.c
index 8ece34d..4a87e94 100644 (file)
--- a/ext/gl/gstgldownloadelement.c
+++ b/ext/gl/gstgldownloadelement.c
@@ -39,6 +39,8 @@ G_DEFINE_TYPE_WITH_CODE (GstGLDownloadElement, gst_gl_download_element,
     GST_DEBUG_CATEGORY_INIT (gst_gl_download_element_debug, "gldownloadelement",
         0, "download element"););
 
+static gboolean gst_gl_download_element_start (GstBaseTransform * bt);
+static gboolean gst_gl_download_element_stop (GstBaseTransform * bt);
 static gboolean gst_gl_download_element_get_unit_size (GstBaseTransform * trans,
     GstCaps * caps, gsize * size);
 static GstCaps *gst_gl_download_element_transform_caps (GstBaseTransform * bt,
@@ -52,6 +54,10 @@ static GstFlowReturn gst_gl_download_element_transform (GstBaseTransform * bt,
     GstBuffer * buffer, GstBuffer * outbuf);
 static gboolean gst_gl_download_element_decide_allocation (GstBaseTransform *
     trans, GstQuery * query);
+static gboolean gst_gl_download_element_sink_event (GstBaseTransform * bt,
+    GstEvent * event);
+static gboolean gst_gl_download_element_src_event (GstBaseTransform * bt,
+    GstEvent * event);
 static void gst_gl_download_element_finalize (GObject * object);
 
 #if GST_GL_HAVE_PLATFORM_EGL && GST_GL_HAVE_DMABUF
@@ -80,6 +86,8 @@ gst_gl_download_element_class_init (GstGLDownloadElementClass * klass)
   GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
+  bt_class->start = gst_gl_download_element_start;
+  bt_class->stop = gst_gl_download_element_stop;
   bt_class->transform_caps = gst_gl_download_element_transform_caps;
   bt_class->set_caps = gst_gl_download_element_set_caps;
   bt_class->get_unit_size = gst_gl_download_element_get_unit_size;
@@ -110,6 +118,31 @@ gst_gl_download_element_init (GstGLDownloadElement * download)
 }
 
 static gboolean
+gst_gl_download_element_start (GstBaseTransform * bt)
+{
+#if GST_GL_HAVE_PLATFORM_EGL && GST_GL_HAVE_DMABUF
+  GstGLDownloadElement *dl = GST_GL_DOWNLOAD_ELEMENT (bt);
+
+  dl->dmabuf_allocator = gst_dmabuf_allocator_new ();
+#endif
+
+  return TRUE;
+}
+
+static gboolean
+gst_gl_download_element_stop (GstBaseTransform * bt)
+{
+  GstGLDownloadElement *dl = GST_GL_DOWNLOAD_ELEMENT (bt);
+
+  if (dl->dmabuf_allocator) {
+    gst_object_unref (GST_OBJECT (dl->dmabuf_allocator));
+    dl->dmabuf_allocator = NULL;
+  }
+
+  return TRUE;
+}
+
+static gboolean
 gst_gl_download_element_set_caps (GstBaseTransform * bt, GstCaps * in_caps,
     GstCaps * out_caps)
 {
@@ -122,27 +155,16 @@ gst_gl_download_element_set_caps (GstBaseTransform * bt, GstCaps * in_caps,
 
   features = gst_caps_get_features (out_caps, 0);
 
-  dl->do_pbo_transfers = FALSE;
-  if (dl->dmabuf_allocator) {
-    gst_object_unref (GST_OBJECT (dl->dmabuf_allocator));
-    dl->dmabuf_allocator = NULL;
-  }
-
-  if (!features) {
-    dl->do_pbo_transfers = TRUE;
-    return TRUE;
-  }
-
   if (gst_caps_features_contains (features, GST_CAPS_FEATURE_MEMORY_GL_MEMORY)) {
-    /* do nothing with the buffer */
+    dl->mode = GST_GL_DOWNLOAD_MODE_PASSTHROUGH;
 #if GST_GL_HAVE_PLATFORM_EGL && GST_GL_HAVE_DMABUF
   } else if (gst_caps_features_contains (features,
           GST_CAPS_FEATURE_MEMORY_DMABUF)) {
-    dl->dmabuf_allocator = gst_dmabuf_allocator_new ();
+    dl->mode = GST_GL_DOWNLOAD_MODE_DMABUF_EXPORTS;
 #endif
-  } else if (gst_caps_features_contains (features,
-          GST_CAPS_FEATURE_MEMORY_SYSTEM_MEMORY)) {
-    dl->do_pbo_transfers = TRUE;
+  } else {
+    /* System Memory */
+    dl->mode = GST_GL_DOWNLOAD_MODE_PBO_TRANSFERS;
   }
 
   return TRUE;
@@ -403,17 +425,8 @@ gst_gl_download_element_prepare_output_buffer (GstBaseTransform * bt,
 
   *outbuf = inbuf;
 
-  if (dl->do_pbo_transfers) {
-    n = gst_buffer_n_memory (*outbuf);
-    for (i = 0; i < n; i++) {
-      GstMemory *mem = gst_buffer_peek_memory (*outbuf, i);
-
-      if (gst_is_gl_memory_pbo (mem))
-        gst_gl_memory_pbo_download_transfer ((GstGLMemoryPBO *) mem);
-    }
-  }
 #if GST_GL_HAVE_PLATFORM_EGL && GST_GL_HAVE_DMABUF
-  else if (dl->dmabuf_allocator) {
+  if (dl->mode == GST_GL_DOWNLOAD_MODE_DMABUF_EXPORTS) {
     GstBuffer *buffer = _try_export_dmabuf (dl, inbuf);
 
     if (buffer) {
@@ -436,13 +449,11 @@ gst_gl_download_element_prepare_output_buffer (GstBaseTransform * bt,
       GstCaps *src_caps;
       GstCapsFeatures *features;
 
-      gst_object_unref (dl->dmabuf_allocator);
-      dl->dmabuf_allocator = NULL;
-
       src_caps = gst_pad_get_current_caps (bt->srcpad);
       src_caps = gst_caps_make_writable (src_caps);
       features = gst_caps_get_features (src_caps, 0);
       gst_caps_features_remove (features, GST_CAPS_FEATURE_MEMORY_DMABUF);
+      dl->mode = GST_GL_DOWNLOAD_MODE_PBO_TRANSFERS;
 
       if (!gst_base_transform_update_src_caps (bt, src_caps)) {
         GST_ERROR_OBJECT (bt, "DMABuf exportation didn't work and system "
@@ -453,6 +464,16 @@ gst_gl_download_element_prepare_output_buffer (GstBaseTransform * bt,
   }
 #endif
 
+  if (dl->mode == GST_GL_DOWNLOAD_MODE_PBO_TRANSFERS) {
+    n = gst_buffer_n_memory (*outbuf);
+    for (i = 0; i < n; i++) {
+      GstMemory *mem = gst_buffer_peek_memory (*outbuf, i);
+
+      if (gst_is_gl_memory_pbo (mem))
+        gst_gl_memory_pbo_download_transfer ((GstGLMemoryPBO *) mem);
+    }
+  }
+
   return GST_FLOW_OK;
 }
 

diff --git a/ext/gl/gstgldownloadelement.h b/ext/gl/gstgldownloadelement.h
index 9e5ef06..8f4f8f1 100644 (file)
--- a/ext/gl/gstgldownloadelement.h
+++ b/ext/gl/gstgldownloadelement.h
@@ -39,11 +39,18 @@ GType gst_gl_download_element_get_type (void);
 typedef struct _GstGLDownloadElement GstGLDownloadElement;
 typedef struct _GstGLDownloadElementClass GstGLDownloadElementClass;
 
+typedef enum
+{
+  GST_GL_DOWNLOAD_MODE_PASSTHROUGH,
+  GST_GL_DOWNLOAD_MODE_PBO_TRANSFERS,
+  GST_GL_DOWNLOAD_MODE_DMABUF_EXPORTS
+} GstGlDownloadMode;
+
 struct _GstGLDownloadElement
 {
   GstGLBaseFilter  parent;
 
-  gboolean do_pbo_transfers;
+  GstGlDownloadMode mode;
   GstAllocator * dmabuf_allocator;
   gboolean add_videometa;
 };