[Spice-devel] [PATCH spice-gtk] gstreamer: set timestamp in buffer's GstReferenceTimestampMeta

[Snir Sheriber]

Currently we set timestamps as buffer's PTS, this value may be changed by
the pipeline in some cases and cause an unexpected buffer warnings (when
GstVideoOverlay is not used). Use GstReferenceTimestampMeta when
synchronization is made by spice.

Signed-off-by: Snir Sheriber <ssheribe at redhat.com>
---

Currently it's causing to an error if you running with DISABLE_GSTVIDEOOVERLAY=1
and start some audio playback in the guest.

---
 src/channel-display-gst.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/channel-display-gst.c b/src/channel-display-gst.c
index 2c07f35..a00f53e 100644
--- a/src/channel-display-gst.c
+++ b/src/channel-display-gst.c
@@ -33,6 +33,10 @@ typedef struct SpiceGstFrame SpiceGstFrame;
 
 /* GStreamer decoder implementation */
 
+#if GST_CHECK_VERSION(1,14,0)
+static GstStaticCaps stream_reference = GST_STATIC_CAPS("timestamp/spice-stream");
+#endif
+
 typedef struct SpiceGstDecoder {
     VideoDecoder base;
 
@@ -88,7 +92,14 @@ struct SpiceGstFrame {
 static SpiceGstFrame *create_gst_frame(GstBuffer *buffer, SpiceFrame *frame)
 {
     SpiceGstFrame *gstframe = g_new(SpiceGstFrame, 1);
+#if GST_CHECK_VERSION(1,14,0)
+    GstReferenceTimestampMeta *time_meta;
+
+    time_meta = gst_buffer_get_reference_timestamp_meta(buffer, gst_static_caps_get(&stream_reference));
+    gstframe->timestamp = time_meta->timestamp;
+#else
     gstframe->timestamp = GST_BUFFER_PTS(buffer);
+#endif
     gstframe->frame = frame;
     gstframe->sample = NULL;
     return gstframe;
@@ -213,6 +224,12 @@ static void fetch_pending_sample(SpiceGstDecoder *decoder)
         decoder->pending_samples--;
 
         GstBuffer *buffer = gst_sample_get_buffer(sample);
+        GstClockTime buffer_ts;
+#if GST_CHECK_VERSION(1,14,0)
+        buffer_ts = gst_buffer_get_reference_timestamp_meta(buffer, gst_static_caps_get(&stream_reference))->timestamp;
+#else
+        buffer_ts = GST_BUFFER_PTS(buffer);
+#endif
 
         /* gst_app_sink_pull_sample() sometimes returns the same buffer twice
          * or buffers that have a modified, and thus unrecognizable, PTS.
@@ -225,7 +242,7 @@ static void fetch_pending_sample(SpiceGstDecoder *decoder)
         GList *l = g_queue_peek_head_link(decoder->decoding_queue);
         while (l) {
             gstframe = l->data;
-            if (gstframe->timestamp == GST_BUFFER_PTS(buffer)) {
+            if (gstframe->timestamp == buffer_ts) {
                 /* The frame is now ready for display */
                 gstframe->sample = sample;
                 decoder->display_frame = gstframe;
@@ -234,7 +251,7 @@ static void fetch_pending_sample(SpiceGstDecoder *decoder)
                  * frames from the decoding queue.
                  */
                 while ((gstframe = g_queue_pop_head(decoder->decoding_queue))) {
-                    if (gstframe->timestamp == GST_BUFFER_PTS(buffer)) {
+                    if (gstframe->timestamp == buffer_ts) {
                         break;
                     }
                     /* The GStreamer pipeline dropped the corresponding
@@ -648,9 +665,13 @@ static gboolean spice_gst_decoder_queue_frame(VideoDecoder *video_decoder,
                                                     frame->data, frame->size, 0, frame->size,
                                                     frame->data_opaque, frame->unref_data);
 
+    GstClockTime pts = gst_clock_get_time(decoder->clock) - gst_element_get_base_time(decoder->pipeline) + ((uint64_t)MAX(0, latency)) * 1000 * 1000;
     GST_BUFFER_DURATION(buffer) = GST_CLOCK_TIME_NONE;
     GST_BUFFER_DTS(buffer) = GST_CLOCK_TIME_NONE;
-    GST_BUFFER_PTS(buffer) = gst_clock_get_time(decoder->clock) - gst_element_get_base_time(decoder->pipeline) + ((uint64_t)MAX(0, latency)) * 1000 * 1000;
+    GST_BUFFER_PTS(buffer) = pts;
+#if GST_CHECK_VERSION(1,14,0)
+    gst_buffer_add_reference_timestamp_meta(buffer, gst_static_caps_get (&stream_reference), pts, GST_CLOCK_TIME_NONE);
+#endif
 
     if (decoder->appsink != NULL) {
         SpiceGstFrame *gst_frame = create_gst_frame(buffer, frame);
-- 
2.19.1