appsink: Force encodebin to create a keyframe when a client connects

This avoids long waits when, for instance, the fps is 3, since the
keyframe-max-dist is 128

1 files changed, 15 insertions, 3 deletions

diff --git a/src/main.c b/src/main.c
index c489f55..2d3e537 100644
--- a/src/main.c
+++ b/src/main.c
@@ -21,6 +21,7 @@
  */
 
 #include <glib-unix.h>
+#include <gst/video/video.h>
 
 #include "lib.h"
 #include "encode.h"
@@ -240,10 +241,11 @@ GET:
     /* A GET request was received. We connect from the pipeline to the
      * client requesting the stream and start writing the response. */
     GstCaps *caps = NULL;
+    GstEvent *event;
     GstBuffer *buffer;
     GstFlowReturn ret;
     GstStateChangeReturn state_change;
-    GstElement *bin, *tee, *q2, *appsink;
+    GstElement *encodebin, *bin, *tee, *q2, *appsink;
     GstPadTemplate *template;
     GstPad *srcpad, *sinkpadq2;
     TranscodeClientCtx *client_ctx;
@@ -322,7 +324,7 @@ GET:
     buffer = stp_get_streamheader_from_caps (caps);
     if (!buffer) {
       g_critical ("Unable to get streamheader from caps");
-      goto nostreamheader;
+      goto force_key_unit;
     }
 
     ret = gst_pad_push (srcpad, buffer);
@@ -332,7 +334,17 @@ GET:
       goto err;
     }
 
-nostreamheader:
+force_key_unit:
+    encodebin = gst_bin_get_by_name (GST_BIN (server_ctx->pipeline),
+                                     "encodebin");
+    event = gst_video_event_new_downstream_force_key_unit (GST_CLOCK_TIME_NONE,
+                                                           GST_CLOCK_TIME_NONE,
+                                                           GST_CLOCK_TIME_NONE,
+                                                           FALSE, 1);
+    if (!gst_element_send_event (encodebin, event))
+      g_critical ("Couldn't send upstream key unit event!");
+    gst_object_unref (encodebin);
+
     client_ctx->appsink = appsink;
 
     g_signal_connect (appsink, "new-sample",