From 62275e8fdbdd37116437f255fd26cae91d3a1c19 Mon Sep 17 00:00:00 2001
From: Quentin Dufour <quentin@deuxfleurs.fr>
Date: Tue, 28 Jan 2020 08:35:01 +0100
Subject: [PATCH] Working sound in loopback

---
 src/dcall.c | 69 +++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 56 insertions(+), 13 deletions(-)

diff --git a/src/dcall.c b/src/dcall.c
index 7055d79..065f4a7 100644
--- a/src/dcall.c
+++ b/src/dcall.c
@@ -1,14 +1,8 @@
 #include <gst/gst.h>
 
-int main(int argc, char *argv[]) {
-  GMainLoop *loop;
-  GstElement *rx, *tx;
+int create_rx_chain(GstElement *pipeline) {
   GstElement *rx_tap, *rx_jitterbuffer, *rx_depay, *rx_opusdec, *rx_resample, *rx_sink;
 
-  gst_init (&argc, &argv);
-  loop = g_main_loop_new (NULL, FALSE);
-
-  rx = gst_pipeline_new ("rx");
   rx_tap = gst_element_factory_make("udpsrc", "rx-tap");
   rx_jitterbuffer = gst_element_factory_make("rtpjitterbuffer", "rx-jitterbuffer");
   rx_depay = gst_element_factory_make("rtpopusdepay", "rx-depay");
@@ -16,8 +10,8 @@ int main(int argc, char *argv[]) {
   rx_resample = gst_element_factory_make("audioresample", "rx-audioresample");
   rx_sink = gst_element_factory_make("autoaudiosink", "rx-sink");
 
-  if (!rx || !rx_tap || !rx_jitterbuffer || !rx_depay || !rx_opusdec || !rx_resample || !rx_sink) {
-    g_printerr ("One element could not be created. Exiting.\n");
+  if (!rx_tap || !rx_jitterbuffer || !rx_depay || !rx_opusdec || !rx_resample || !rx_sink) {
+    g_printerr ("One element of the rx chain could not be created. Exiting.\n");
     return -1;
   }
 
@@ -31,18 +25,67 @@ int main(int argc, char *argv[]) {
   g_object_set(G_OBJECT (rx_opusdec), "plc", TRUE, NULL);
   g_object_set(G_OBJECT (rx_opusdec), "use-inband-fec", FALSE, NULL);
 
-  gst_bin_add_many (GST_BIN (rx), rx_tap, rx_jitterbuffer, rx_depay, rx_opusdec, rx_resample, rx_sink, NULL);
+  gst_bin_add_many (GST_BIN (pipeline), rx_tap, rx_jitterbuffer, rx_depay, rx_opusdec, rx_resample, rx_sink, NULL);
   gst_element_link_many (rx_tap, rx_jitterbuffer, rx_depay, rx_opusdec, rx_resample, rx_sink, NULL);
 
-  gst_element_set_state (rx, GST_STATE_PLAYING);
+  return 0;
+}
+
+int create_tx_chain(GstElement *pipeline) {
+  GstElement *tx_tap, *tx_resample, *tx_opusenc, *tx_pay, *tx_sink;
+
+  tx_tap = gst_element_factory_make("autoaudiosrc", "tx-tap");
+  tx_resample = gst_element_factory_make("audioresample", "tx-resample");
+  tx_opusenc = gst_element_factory_make("opusenc", "tx-opusenc");
+  tx_pay = gst_element_factory_make("rtpopuspay", "tx-rtpopuspay");
+  tx_sink = gst_element_factory_make("udpsink", "tx-sink");
+
+  if (!tx_tap || !tx_resample || !tx_opusenc || !tx_pay || !tx_sink) {
+    g_printerr("One element of the tx chain could not be created. Exiting.\n");
+    return -1;
+  }
+
+  gst_util_set_object_arg(G_OBJECT(tx_opusenc), "audio-type", "voice");
+  g_object_set(G_OBJECT(tx_opusenc), "inband-fec", FALSE, NULL);
+  g_object_set(G_OBJECT(tx_opusenc), "frame-size", 40, NULL);
+  g_object_set(G_OBJECT(tx_opusenc), "bitrate", 32000, NULL);
+  g_object_set(G_OBJECT(tx_opusenc), "dtx", FALSE, NULL); // gstreamer dtx opus implem. is broken
+
+  g_object_set(G_OBJECT(tx_sink), "host", "127.0.0.1", NULL);
+  g_object_set(G_OBJECT(tx_sink), "port", 5000, NULL);
+  g_object_set(G_OBJECT(tx_sink), "async", FALSE, NULL);
+
+  gst_bin_add_many(GST_BIN(pipeline), tx_tap, tx_resample, tx_opusenc, tx_pay, tx_sink, NULL);
+  gst_element_link_many(tx_tap, tx_resample, tx_opusenc, tx_pay, tx_sink, NULL);
+
+  return 0;
+}
+
+int main(int argc, char *argv[]) {
+  GMainLoop *loop;
+  GstElement *pipeline;
+
+  gst_init (&argc, &argv);
+  loop = g_main_loop_new (NULL, FALSE);
+
+  pipeline = gst_pipeline_new ("pipeline");
+  if (!pipeline) {
+    g_printerr ("Pipeline could not be created. Exiting.\n");
+    return -1;
+  }
+
+  if (create_rx_chain (pipeline) != 0) return -1;
+  if (create_tx_chain (pipeline) != 0) return -1;
+
+  gst_element_set_state (pipeline, GST_STATE_PLAYING);
 
   g_print ("Running...\n");
   g_main_loop_run (loop);
 
   g_print ("Returned, stopping playback\n");
-  gst_element_set_state (rx, GST_STATE_NULL);
+  gst_element_set_state (pipeline, GST_STATE_NULL);
 
-  gst_object_unref (GST_OBJECT (rx));
+  gst_object_unref (GST_OBJECT (pipeline));
   g_main_loop_unref (loop);
 
   return 0;