>
> From: Victor Toso <me@xxxxxxxxxxxxxx>
>
> The Playbin can provide the full pipeline which reduces the
> overall maintenance in the code as we don't need to track which
> decoder can work with our stream type.
>
> We need to maintain the GstCaps per SPICE_VIDEO_CODEC_TYPE in order to
> tell Playbin the type of data we expect. This much should be covered
> by spice-protocol and very likely we will need to extend it in the
> future to allow more settings that might not possible to verify at
> runtime.
>
> This patch keeps previous code for compatibility reasons.
>
> Note that we have to wait Playbin to emit "source-setup" in order to
> configure GstAppSrc with the capabilities of input stream. If in the
> unlikely event of frames arriving while GstAppSrc is not setup, we
> will drop those frames.
>
On the other side you'll get also gibberish till next I frame
which can happens seconds later.
> Signed-off-by: Victor Toso <victortoso@xxxxxxxxxx>
> Signed-off-by: Victor Toso <me@xxxxxxxxxxxxxx>
> ---
> src/channel-display-gst.c | 88
> +++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 86 insertions(+), 2 deletions(-)
>
> diff --git a/src/channel-display-gst.c b/src/channel-display-gst.c
> index 2a20763..2b14745 100644
> --- a/src/channel-display-gst.c
> +++ b/src/channel-display-gst.c
> @@ -50,6 +50,9 @@ typedef struct SpiceGstDecoder {
> guint timer_id;
> } SpiceGstDecoder;
>
> +/* FIXME: With gstreamer version 1.9.0 and higher, we are using playbin to
> + * create the pipeline for us and for that reason we don't need to keep
> track of
> + * decoder's name anymore. */
> static struct {
> const gchar *dec_name;
> const gchar *dec_caps;
> @@ -256,10 +259,13 @@ static GstFlowReturn new_sample(GstAppSink *gstappsink,
> gpointer video_decoder)
> }
> l = l->next;
> }
> +#if !GST_CHECK_VERSION(1,9,0)
> + /* We down own this sample when using playbin, no need to unref it
> */
This looks a bug to me. gst_app_sink_pull_sample documentation state that
you should call gst_sample_unref. Also note that if the frame is expected
sample is attached to a SpiceFrame and later unreferenced in free_frame.
So some samples will get unreferenced and others not.
> if (!l) {
> spice_warning("got an unexpected decoded buffer!");
> gst_sample_unref(sample);
> }
> +#endif
>
> g_mutex_unlock(&decoder->queues_mutex);
> schedule_frame(decoder);
> @@ -276,8 +282,11 @@ static void free_pipeline(SpiceGstDecoder *decoder)
> }
>
> gst_element_set_state(decoder->pipeline, GST_STATE_NULL);
> +#if !GST_CHECK_VERSION(1,9,0)
> + /* Owned by playbin on 1.9.0 onwards */
> gst_object_unref(decoder->appsrc);
> gst_object_unref(decoder->appsink);
So we have pointer which we don't own, IMHO better to use g_object_ref.
> +#endif
> gst_object_unref(decoder->pipeline);
> gst_object_unref(decoder->clock);
> decoder->pipeline = NULL;
> @@ -305,13 +314,79 @@ static gboolean handle_pipeline_message(GstBus *bus,
> GstMessage *msg, gpointer v
> return TRUE;
> }
>
> +#if GST_CHECK_VERSION(1,9,0)
> +static void app_source_setup(GstElement *pipeline, GstElement *source,
> SpiceGstDecoder *decoder)
> +{
> + GstCaps *caps;
> +
> + /* - We schedule the frame display ourselves so set sync=false on
> appsink
> + * so the pipeline decodes them as fast as possible. This will also
> + * minimize the risk of frames getting lost when we rebuild the
> + * pipeline.
> + * - Set max-bytes=0 on appsrc so it does not drop frames that may be
> + * needed by those that follow.
> + */
> + caps =
> gst_caps_from_string(gst_opts[decoder->base.codec_type].dec_caps);
> + g_object_set(source,
> + "caps", caps,
> + "is-live", TRUE,
> + "format", GST_FORMAT_TIME,
> + "max-bytes", 0,
> + "block", TRUE,
> + NULL);
> + gst_caps_unref(caps);
> + decoder->appsrc = GST_APP_SRC(source);
g_object_ref
> +}
> +#endif
> +
> static gboolean create_pipeline(SpiceGstDecoder *decoder)
> {
> - gchar *desc;
> GstAppSinkCallbacks appsink_cbs = { NULL };
> - GError *err = NULL;
> GstBus *bus;
> +#if GST_CHECK_VERSION(1,9,0)
> + GstElement *playbin, *sink;
> + gint flags;
> + GstCaps *caps;
>
> + playbin = gst_element_factory_make("playbin", "playbin");
> + if (playbin == NULL) {
> + spice_warning("error upon creation of 'playbin' element");
> + return FALSE;
> + }
> +
> + sink = gst_element_factory_make("appsink", "sink");
> + if (sink == NULL) {
> + spice_warning("error upon creation of 'appsink' element");
> + gst_object_unref(playbin);
> + return FALSE;
> + }
> +
> + caps = gst_caps_from_string("video/x-raw,format=BGRx");
> + g_object_set(sink,
> + "caps", caps,
> + "sync", FALSE,
> + "drop", FALSE,
> + NULL);
> + gst_caps_unref(caps);
> +
> + g_object_set(playbin,
> + "uri", "appsrc://",
> + "video-sink", sink,
How this change the ownership of sink? Do we still own it?
> + NULL);
> +
> + g_signal_connect(playbin, "source-setup", G_CALLBACK(app_source_setup),
> decoder);
isn't that racy? playbin could in theory send the signal before
we connect it.
> +
> + /* Disable audio in playbin */
> + g_object_get(playbin, "flags", &flags, NULL);
> + flags &= ~(1 << 1);
No mnemonic? gst-inspect report the flags.
Why is needed to disable? To save memory?
Should we not disable other stuff like subtitles?
> + g_object_set(playbin, "flags", flags, NULL);
> +
> + decoder->appsrc = NULL;
This potentially will override the value written by app_source_setup.
Would be better to use some mutex+condition in order to wait
app_source_setup to set this value. Kind of
lock(mtx);
if (!appsrc)
wait_cond(cond);
unlock(mtx);
here and
lock(mtx);
appsrc = g_object_ref(source);
signal(cond);
unlock(mtx);
in app_source_setup.
> + decoder->appsink = GST_APP_SINK(sink);
g_object_ref? Not clear if we still own sink pointer here.
> + decoder->pipeline = playbin;
> +#else
> + gchar *desc;
> + GError *err = NULL;
>
> /* - We schedule the frame display ourselves so set sync=false on
> appsink
> * so the pipeline decodes them as fast as possible. This will also
> @@ -337,6 +412,7 @@ static gboolean create_pipeline(SpiceGstDecoder *decoder)
>
> decoder->appsrc =
> GST_APP_SRC(gst_bin_get_by_name(GST_BIN(decoder->pipeline), "src"));
> decoder->appsink =
> GST_APP_SINK(gst_bin_get_by_name(GST_BIN(decoder->pipeline), "sink"));
> +#endif
>
> appsink_cbs.new_sample = new_sample;
> gst_app_sink_set_callbacks(decoder->appsink, &appsink_cbs, decoder,
> NULL);
> @@ -447,6 +523,14 @@ static gboolean
> spice_gst_decoder_queue_frame(VideoDecoder *video_decoder,
> return FALSE;
> }
>
> +#if GST_CHECK_VERSION(1,9,0)
> + if (decoder->appsrc == NULL) {
> + spice_warning("Error: Playbin has not yet initialized the Appsrc
> element");
> + stream_dropped_frame_on_playback(decoder->base.stream);
> + return TRUE;
> + }
> +#endif
> +
I'd find a way to remove this
> /* ref() the frame_msg for the buffer */
> spice_msg_in_ref(frame_msg);
> GstBuffer *buffer =
> gst_buffer_new_wrapped_full(GST_MEMORY_FLAG_PHYSICALLY_CONTIGUOUS,
Frediano
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