commit 06321a39e07b3bc4a9f5701e86c0b70c702b8d7e
author Vasil Velichkov <vvvelichkov@gmail.com> Tue May 15 21:36:14 2018 +0300
committer Piotr Krysik <ptrkrysik@gmail.com> Sat Dec 29 00:52:05 2018 +0100
tree 345ae1b80c2758637d60050e69d875971b79183e
parent 6ade8b8f19e95934db9a6897a7bc3bd965c3d1fc

Improve voice boundary detection

Decode Alerting and Progress messages and if the in-band information
flag is set start decoding the voice

lib/decoding/tch_h_decoder_impl.cc

diff --git a/lib/decoding/tch_h_decoder_impl.cc b/lib/decoding/tch_h_decoder_impl.cc
index b7672e3..d2f29c7 100644
--- a/lib/decoding/tch_h_decoder_impl.cc
+++ b/lib/decoding/tch_h_decoder_impl.cc
@@ -293,8 +293,29 @@
                     // check if this is a call control message
                     if ((frameBuffer[3] & 0x0f) == 0x03)
                     {
+                        // Alerting
+                        if ((frameBuffer[4] & 0x3f) == 0x01)
+                        {
+                            if ((frameBuffer[5] == 0x1e) && //element id
+                                    (frameBuffer[6] == 2) && //length
+                                    ((frameBuffer[8] & 0x7f) == 0x08))
+                            {
+                                //.000 1000 = Progress description: In-band information or appropriate pattern now available (8)
+                                d_boundary_decode = true;
+                            }
+                        }
+                        // Progress
+                        else if ((frameBuffer[4] & 0x3f) == 0x03)
+                        {
+                            if ((frameBuffer[5] == 2) && //length
+                                    (frameBuffer[7] & 0x7f) == 0x08)
+                            {
+                                //.000 1000 = Progress description: In-band information or appropriate pattern now available (8)
+                                d_boundary_decode = true;
+                            }
+                        }
                         // Connect specified in GSM 04.08, 9.3.5
-                        if ((frameBuffer[4] & 0x3f) == 0x07)
+                        else if ((frameBuffer[4] & 0x3f) == 0x07)
                         {
                             d_boundary_decode = true;
                         }