From: Joshua C. Colp <jcolp@sangoma.com>
Date: Tue, 19 May 2020 09:18:58 +0000 (-0300)
Subject: bridge_softmix: Always remove audio from mixed frame.
X-Git-Tag: 13.34.0-rc1~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=17a878dd9945e1b395d5d93b2ad88303713e44cc;p=thirdparty%2Fasterisk.git

bridge_softmix: Always remove audio from mixed frame.

When receiving audio from a channel we determine if it
is talking or silence based on a threshold value. If
this threshold is met we always mix the audio into the
conference bridge. If this threshold is not met we also
mix the audio into the conference bridge UNLESS the
drop silence option is enabled.

The code that removed the audio from the mixed frame
assumed that it was always not present if it did not
meet the threshold to be considered talking. This is
incorrect. If it has been stated that the audio was
mixed into the mixed frame then it has been mixed into
the mixed frame. By not removing audio that was
considered non-talking it was possible for a channel
to receive a slight echo of audio of itself at times.

This change ensures that the audio is always removed
from the mixed frame going back to the channel so it
no longer receives the slight echo.

ASTERISK-28898

Change-Id: I7b1b582cc1bcdb318ecc60c9d2e3d87ae31d55cb
---

diff --git a/bridges/bridge_softmix.c b/bridges/bridge_softmix.c
index ac4e357261..65a08b512b 100644
--- a/bridges/bridge_softmix.c
+++ b/bridges/bridge_softmix.c
@@ -282,9 +282,8 @@ static void softmix_process_write_audio(struct softmix_translate_helper *trans_h
 	struct softmix_translate_helper_entry *entry = NULL;
 	int i;
 
-	/* If we provided audio that was not determined to be silence,
-	 * then take it out while in slinear format. */
-	if (sc->have_audio && sc->talking) {
+	/* If we provided any audio then take it out while in slinear format. */
+	if (sc->have_audio) {
 		for (i = 0; i < sc->write_frame.samples; i++) {
 			ast_slinear_saturated_subtract(&sc->final_buf[i], &sc->our_buf[i]);
 		}