[Spice-devel] [spice v13 10/29] server: Handle and recover from GStreamer encoding errors

[Francois Gouget]

On Tue, 3 May 2016, Christophe Fergeau wrote:
[...]
> And GStreamer GstBus/GstAppSink API tends to be async, while we need
> encode_frame() to be sync, so there is indeed several useful APIs that
> we cannot use without additional complexity. I'm wondering if the
> simpler patch attached to this message could work too.

I had tried that but while it works you get a big warning that changing 
the state of the pipeline from the streaming thread is not allowed:

(Xorg:29234): Spice-WARNING **: gstreamer-encoder.c:809:handle_pipeline_message: GStreamer error from element encoder: Can not initialize x264 encoder.
gstreamer-encoder.c:809:handle_pipeline_message: GStreamer error from element encoder: Can not initialize x264 encoder.
gstreamer-encoder.c:811:handle_pipeline_message: debug details: gstx264enc.c(1269): gst_x264_enc_init_encoder (): /GstPipeline:pipeline3/GstX264Enc:encoder
0:00:09.382605905 29234 0x7f3de0855e80 DEBUG             GST_STATES gstelement.c:2638:gst_element_set_state_func:<pipeline3> set_state to NULL
[...]
0:00:09.384261060 29234 0x7f3de0855e80 WARN                    task gsttask.c:862:gst_task_join:<src:src> trying to join task from its thread

(Xorg:29234): GStreamer-WARNING **: 
Trying to join task 0x7f3de00f7560 from its thread would deadlock.
You cannot change the state of an element from its streaming
thread. Use g_idle_add() or post a GstMessage on the bus to
schedule the state change from the main thread.

0:00:09.384286706 29234 0x7f3de0855e80 DEBUG               GST_PADS gstpad.c:5731:gst_pad_stop_task:<src:src> join failed
0:00:09.384291170 29234 0x7f3de0855e80 DEBUG                basesrc gstbasesrc.c:2854:gst_base_src_stop:<src> stopping source


> > Also I'm not convinced we really have a glib main loop in Xspice. If we 
> > did I would expect APIs like g_idle_source_new() to work. See: 
> > https://lists.freedesktop.org/archives/spice-devel/2016-March/027502.html
> 
> Yes, I addressed this in
> https://lists.freedesktop.org/archives/spice-devel/2016-March/027550.html
> « One gotcha though is that queueing an idle this way is currently not
> working, you have to workaround it with g_timeout_source_new(1).

I had tried using g_timeout_add() but maybe I was missing the 
g_timeout_source_new() call. In any case I'm not sure it would really 
help.


-- 
Francois Gouget <fgouget at codeweavers.com>