[Spice-devel] [PATCH spice-gtk] streaming: make draw-area visible on MJPEG encoder creation

[Kevin Pouget]

This patch allows the MJPEG encoder to inform the spice-widget that
its video drawing area (draw-area) should be made visible on screen.

This is required to switch from GST video decoding to native MJPEG
decoding, otherwise the gst-area remained on top and the MJPEG video
stream was never shown.

Signed-off-by: Kevin Pouget <kpouget at redhat.com>
---

I have simplified the patch to reuse the existing
SPICE_DISPLAY_OVERLAY signal (with pipeline_ptr == NULL), instead of
creating a new one dedicated to the native MJPEG decoder.

---
 src/channel-display-mjpeg.c |  2 ++
 src/channel-display-priv.h  |  2 +-
 src/channel-display.c       | 12 ++++++++++++
 src/spice-widget.c          |  9 ++++++++-
 4 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/channel-display-mjpeg.c b/src/channel-display-mjpeg.c
index 647d31b..6f1a4d7 100644
--- a/src/channel-display-mjpeg.c
+++ b/src/channel-display-mjpeg.c
@@ -300,5 +300,7 @@ VideoDecoder* create_mjpeg_decoder(int codec_type, display_stream *stream)

     /* All the other fields are initialized to zero by g_new0(). */

+    show_mjpeg_widget(stream);
+
     return (VideoDecoder*)decoder;
 }
diff --git a/src/channel-display-priv.h b/src/channel-display-priv.h
index b5d6728..90e08ac 100644
--- a/src/channel-display-priv.h
+++ b/src/channel-display-priv.h
@@ -198,7 +198,7 @@ void stream_dropped_frame_on_playback(display_stream *st);
 void stream_display_frame(display_stream *st, SpiceFrame *frame, uint32_t width, uint32_t height, int stride, uint8_t* data);
 guintptr get_window_handle(display_stream *st);
 gboolean hand_pipeline_to_widget(display_stream *st,  GstPipeline *pipeline);
-
+gboolean show_mjpeg_widget(display_stream *st);
 void spice_frame_free(SpiceFrame *frame);

 G_END_DECLS
diff --git a/src/channel-display.c b/src/channel-display.c
index 59c809d..b8a27e3 100644
--- a/src/channel-display.c
+++ b/src/channel-display.c
@@ -1484,6 +1484,18 @@ gboolean hand_pipeline_to_widget(display_stream *st, GstPipeline *pipeline)
     return res;
 }

+G_GNUC_INTERNAL
+gboolean show_mjpeg_widget(display_stream *st)
+{
+    gboolean res = false;
+
+    if (st->surface->streaming_mode) {
+        g_signal_emit(st->channel, signals[SPICE_DISPLAY_OVERLAY], 0, NULL, &res);
+    }
+
+    return res;
+}
+
 /* after a sequence of 3 drops, push a report to the server, even
  * if the report window is bigger */
 #define STREAM_REPORT_DROP_SEQ_LEN_LIMIT 3
diff --git a/src/spice-widget.c b/src/spice-widget.c
index a9ba1f1..7c257ff 100644
--- a/src/spice-widget.c
+++ b/src/spice-widget.c
@@ -2780,13 +2780,20 @@ static void gst_size_allocate(GtkWidget *widget, GdkRectangle *a, gpointer data)
 }

 /* This callback should pass to the widget a pointer of the pipeline
- * so that we can set pipeline and overlay related calls from here.
+ * so that we can the set GST pipeline and overlay related calls from
+ * here.  If the pipeline pointer is NULL, the drawing area of the
+ * native renderer is set visible.
  */
 static gboolean set_overlay(SpiceChannel *channel, void* pipeline_ptr, SpiceDisplay *display)
 {
 #if defined(GDK_WINDOWING_X11)
     SpiceDisplayPrivate *d = display->priv;

+    if (pipeline_ptr == NULL) {
+        gtk_stack_set_visible_child_name(d->stack, "draw-area");
+        return true;
+    }
+
     /* GstVideoOverlay is currently used only under x */
     if (!g_getenv("DISABLE_GSTVIDEOOVERLAY") &&
         GDK_IS_X11_DISPLAY(gdk_display_get_default())) {
--
2.21.0