srt: Add support for streamheaders to sinks

https://bugzilla.gnome.org/show_bug.cgi?id=793503

ext/srt/gstsrtbasesink.c

@@ -123,15 +123,70 @@ gst_srt_base_sink_finalize (GObject * object)
 {
   GstSRTBaseSink *self = GST_SRT_BASE_SINK (object);
 
+  g_clear_pointer (&self->headers, gst_buffer_list_unref);
   g_clear_pointer (&self->uri, gst_uri_unref);
   g_clear_pointer (&self->passphrase, g_free);
 
   G_OBJECT_CLASS (parent_class)->finalize (object);
 }
 
+static gboolean
+gst_srt_base_sink_set_caps (GstBaseSink * sink, GstCaps * caps)
+{
+  GstSRTBaseSink *self = GST_SRT_BASE_SINK (sink);
+  GstStructure *s;
+  const GValue *streamheader;
+
+  GST_DEBUG_OBJECT (self, "setcaps %" GST_PTR_FORMAT, caps);
+
+  g_clear_pointer (&self->headers, gst_buffer_list_unref);
+
+  s = gst_caps_get_structure (caps, 0);
+  streamheader = gst_structure_get_value (s, "streamheader");
+
+  if (!streamheader) {
+    GST_DEBUG_OBJECT (self, "'streamheader' field not present");
+  } else if (GST_VALUE_HOLDS_BUFFER (streamheader)) {
+    GST_DEBUG_OBJECT (self, "'streamheader' field holds buffer");
+    self->headers = gst_buffer_list_new_sized (1);
+    gst_buffer_list_add (self->headers, g_value_dup_boxed (streamheader));
+  } else if (GST_VALUE_HOLDS_ARRAY (streamheader)) {
+    guint i, size;
+
+    GST_DEBUG_OBJECT (self, "'streamheader' field holds array");
+
+    size = gst_value_array_get_size (streamheader);
+    self->headers = gst_buffer_list_new_sized (size);
+
+    for (i = 0; i < size; i++) {
+      const GValue *v = gst_value_array_get_value (streamheader, i);
+      if (!GST_VALUE_HOLDS_BUFFER (v)) {
+        GST_ERROR_OBJECT (self, "'streamheader' item of unexpected type '%s'",
+            G_VALUE_TYPE_NAME (v));
+        return FALSE;
+      }
+
+      gst_buffer_list_add (self->headers, g_value_dup_boxed (v));
+    }
+  } else {
+    GST_ERROR_OBJECT (self, "'streamheader' field has unexpected type '%s'",
+        G_VALUE_TYPE_NAME (streamheader));
+    return FALSE;
+  }
+
+  GST_DEBUG_OBJECT (self, "Collected streamheaders: %u buffers",
+      self->headers ? gst_buffer_list_length (self->headers) : 0);
+
+  return TRUE;
+}
+
 static gboolean
 gst_srt_base_sink_stop (GstBaseSink * sink)
 {
+  GstSRTBaseSink *self = GST_SRT_BASE_SINK (sink);
+
+  g_clear_pointer (&self->headers, gst_buffer_list_unref);
+
   return TRUE;
 }
 
@@ -143,6 +198,12 @@ gst_srt_base_sink_render (GstBaseSink * sink, GstBuffer * buffer)
   GstSRTBaseSinkClass *bclass = GST_SRT_BASE_SINK_GET_CLASS (sink);
   GstFlowReturn ret = GST_FLOW_OK;
 
+  if (self->headers && GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_HEADER)) {
+    GST_DEBUG_OBJECT (self, "Have streamheaders,"
+        " ignoring header %" GST_PTR_FORMAT, buffer);
+    return GST_FLOW_OK;
+  }
+
   GST_TRACE_OBJECT (self, "sending buffer %p, offset %"
       G_GINT64_FORMAT ", offset_end %" G_GINT64_FORMAT
       ", timestamp %" GST_TIME_FORMAT ", duration %" GST_TIME_FORMAT
@@ -203,6 +264,7 @@ gst_srt_base_sink_class_init (GstSRTBaseSinkClass * klass)
 
   g_object_class_install_properties (gobject_class, PROP_LAST, properties);
 
+  gstbasesink_class->set_caps = GST_DEBUG_FUNCPTR (gst_srt_base_sink_set_caps);
   gstbasesink_class->stop = GST_DEBUG_FUNCPTR (gst_srt_base_sink_stop);
   gstbasesink_class->render = GST_DEBUG_FUNCPTR (gst_srt_base_sink_render);
 }
@@ -283,6 +345,46 @@ gst_srt_base_sink_uri_handler_init (gpointer g_iface, gpointer iface_data)
   iface->set_uri = gst_srt_base_sink_uri_set_uri;
 }
 
+gboolean
+gst_srt_base_sink_send_headers (GstSRTBaseSink * self,
+    GstSRTBaseSinkSendCallback send_cb, gpointer user_data)
+{
+  guint size, i;
+
+  g_return_val_if_fail (GST_IS_SRT_BASE_SINK (self), FALSE);
+  g_return_val_if_fail (send_cb, FALSE);
+
+  if (!self->headers)
+    return TRUE;
+
+  size = gst_buffer_list_length (self->headers);
+
+  GST_DEBUG_OBJECT (self, "Sending %u stream headers", size);
+
+  for (i = 0; i < size; i++) {
+    GstBuffer *buffer = gst_buffer_list_get (self->headers, i);
+    GstMapInfo info;
+    gboolean ret;
+
+    GST_TRACE_OBJECT (self, "sending header %u %" GST_PTR_FORMAT, i, buffer);
+
+    if (!gst_buffer_map (buffer, &info, GST_MAP_READ)) {
+      GST_ELEMENT_ERROR (self, RESOURCE, READ,
+          ("Could not map the input stream"), (NULL));
+      return FALSE;
+    }
+
+    ret = send_cb (self, &info, user_data);
+
+    gst_buffer_unmap (buffer, &info);
+
+    if (!ret)
+      return FALSE;
+  }
+
+  return TRUE;
+}
+
 GstStructure *
 gst_srt_base_sink_get_stats (GSocketAddress * sockaddr, SRTSOCKET sock)
 {

ext/srt/gstsrtbasesink.h

@@ -45,6 +45,7 @@ struct _GstSRTBaseSink {
   GstBaseSink parent;
 
   GstUri *uri;
+  GstBufferList *headers;
   gint latency;
   gchar *passphrase;
   gint key_length;
@@ -65,6 +66,12 @@ struct _GstSRTBaseSinkClass {
 GST_EXPORT
 GType gst_srt_base_sink_get_type (void);
 
+typedef gboolean (*GstSRTBaseSinkSendCallback) (GstSRTBaseSink *sink,
+    const GstMapInfo *mapinfo, gpointer user_data);
+
+gboolean gst_srt_base_sink_send_headers (GstSRTBaseSink *sink,
+    GstSRTBaseSinkSendCallback send_cb, gpointer user_data);
+
 GstStructure * gst_srt_base_sink_get_stats (GSocketAddress *sockaddr,
     SRTSOCKET sock);
 

ext/srt/gstsrtclientsink.c

@@ -68,6 +68,8 @@ struct _GstSRTClientSinkPrivate
   gboolean rendez_vous;
   gchar *bind_address;
   guint16 bind_port;
+
+  gboolean sent_headers;
 };
 
 #define GST_SRT_CLIENT_SINK_GET_PRIVATE(obj)  \
@@ -190,6 +192,14 @@ gst_srt_client_sink_send_buffer (GstSRTBaseSink * sink,
   GstSRTClientSink *self = GST_SRT_CLIENT_SINK (sink);
   GstSRTClientSinkPrivate *priv = GST_SRT_CLIENT_SINK_GET_PRIVATE (self);
 
+  if (!priv->sent_headers) {
+    if (!gst_srt_base_sink_send_headers (sink, send_buffer_internal,
+            GINT_TO_POINTER (priv->sock)))
+      return FALSE;
+
+    priv->sent_headers = TRUE;
+  }
+
   return send_buffer_internal (sink, mapinfo, GINT_TO_POINTER (priv->sock));
 }
 
@@ -214,6 +224,8 @@ gst_srt_client_sink_stop (GstBaseSink * sink)
 
   g_clear_object (&priv->sockaddr);
 
+  priv->sent_headers = FALSE;
+
   return GST_BASE_SINK_CLASS (parent_class)->stop (sink);
 }
 

ext/srt/gstsrtserversink.c

@@ -103,6 +103,7 @@ typedef struct
 {
   int sock;
   GSocketAddress *sockaddr;
+  gboolean sent_headers;
 } SRTClient;
 
 static SRTClient *
@@ -418,6 +419,12 @@ gst_srt_server_sink_send_buffer (GstSRTBaseSink * sink,
     SRTClient *client = clients->data;
     clients = clients->next;
 
+    if (!client->sent_headers) {
+      if (!gst_srt_base_sink_send_headers (sink, send_buffer_internal, client))
+        goto err;
+
+      client->sent_headers = TRUE;
+    }
 
     if (!send_buffer_internal (sink, mapinfo, client))
       goto err;