From 19e7f8f1198490645e5607a0da8ae7e5d7b73710 Mon Sep 17 00:00:00 2001
From: Evangelos Ribeiro Tzaras <evangelos.tzaras@puri.sm>
Date: Mon, 15 Mar 2021 16:36:05 +0100
Subject: [PATCH] sip-media: enable echo cancellation

by setting "filter.want" to "echo-cancel" for the pulsesink and pulsesrc
GStElement's.
---
 plugins/sip/calls-sip-media-pipeline.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/plugins/sip/calls-sip-media-pipeline.c b/plugins/sip/calls-sip-media-pipeline.c
index 0b11d12..1edba91 100644
--- a/plugins/sip/calls-sip-media-pipeline.c
+++ b/plugins/sip/calls-sip-media-pipeline.c
@@ -326,6 +326,7 @@ initable_init (GInitable    *initable,
   GstCaps *caps;
   g_autofree char *caps_string = NULL;
   GstPad *srcpad, *sinkpad;
+  GstStructure *props = NULL;
 
   /* could also use autoaudiosink instead of pulsesink */
   self->audiosink = gst_element_factory_make ("pulsesink", "sink");
@@ -423,6 +424,24 @@ initable_init (GInitable    *initable,
     return FALSE;
   }
 
+  /* enable echo cancellation and set buffer size to 40ms */
+  props = gst_structure_new ("props",
+                             "media.role", G_TYPE_STRING, "phone",
+                             "filter.want", G_TYPE_STRING, "echo-cancel",
+                             NULL);
+
+  g_object_set (self->audiosink,
+                "buffer-time", (gint64) 40000,
+                "stream-properties", props,
+                NULL);
+
+  g_object_set (self->audiosrc,
+                "buffer-time", (gint64) 40000,
+                "stream-properties", props,
+                NULL);
+
+  gst_structure_free (props);
+
   gst_bin_add (GST_BIN (self->send_pipeline), self->send_rtpbin);
   gst_bin_add (GST_BIN (self->recv_pipeline), self->recv_rtpbin);