bridge_softmix / res_rtp_asterisk: Fix packet loss and renegotiation issues.

This change does a few things to improve packet loss and renegotiation:

1. On outgoing RTP streams we will now properly reflect out of order
packets and packet loss in the sequence number. This allows the
remote jitterbuffer to better reorder things.

2. Video updates can now be discarded for a period of time
after one has been sent to prevent flooding of clients.

3. For declined and removed streams we will now release any
media session resources associated with them. This was not
previously done and caused an issue where old state was being
used for a new stream.

4. RTP bundling was not actually removing bundled RTP instances
from the parent. This has been resolved by removing based on
the RTP instance itself and not the SSRC.

5. The code did not properly handle explicitly unbundling an
RTP instance from its parent. This now works as expected.

ASTERISK-27143

Change-Id: Ibd91362f0e4990b6129638e712bc8adf0899fd45

3 files changed, 15 insertions, 0 deletions

diff --git a/apps/app_confbridge.c b/apps/app_confbridge.c
index c6372fa2f..b2d612df3 100644
--- a/apps/app_confbridge.c
+++ b/apps/app_confbridge.c
@@ -1485,6 +1485,7 @@ static struct confbridge_conference *join_conference_bridge(const char *conferen
 			ast_bridge_set_talker_src_video_mode(conference->bridge);
 		} else if (ast_test_flag(&conference->b_profile, BRIDGE_OPT_VIDEO_SRC_SFU)) {
 			ast_bridge_set_sfu_video_mode(conference->bridge);
+			ast_bridge_set_video_update_discard(conference->bridge, conference->b_profile.video_update_discard);
 		}
 
 		/* Link it into the conference bridges container */
diff --git a/apps/confbridge/conf_config_parser.c b/apps/confbridge/conf_config_parser.c
index cc8fcfe5d..bfd9f4f56 100644
--- a/apps/confbridge/conf_config_parser.c
+++ b/apps/confbridge/conf_config_parser.c
@@ -450,6 +450,16 @@
 						</enumlist>
 					</description>
 				</configOption>
+				<configOption name="video_update_discard" default="2000">
+					<synopsis>Sets the amount of time in milliseconds after sending a video update to discard subsequent video updates</synopsis>
+					<description><para>
+						Sets the amount of time in milliseconds after sending a video update request
+						that subsequent video updates should be discarded. This means that if we
+						send a video update we will discard any other video update requests until
+						after the configured amount of time has elapsed. This prevents flooding of
+						video update requests from clients.
+					</para></description>
+				</configOption>
 				<configOption name="template">
 					<synopsis>When using the CONFBRIDGE dialplan function, use a bridge profile as a template for creating a new temporary profile</synopsis>
 				</configOption>
@@ -1652,6 +1662,8 @@ static char *handle_cli_confbridge_show_bridge_profile(struct ast_cli_entry *e,
 		break;
 	}
 
+	ast_cli(a->fd,"Video Update Discard: %u\n", b_profile.video_update_discard);
+
 	ast_cli(a->fd,"sound_only_person:    %s\n", conf_get_sound(CONF_SOUND_ONLY_PERSON, b_profile.sounds));
 	ast_cli(a->fd,"sound_only_one:       %s\n", conf_get_sound(CONF_SOUND_ONLY_ONE, b_profile.sounds));
 	ast_cli(a->fd,"sound_has_joined:     %s\n", conf_get_sound(CONF_SOUND_HAS_JOINED, b_profile.sounds));
@@ -2220,6 +2232,7 @@ int conf_load_config(void)
 	aco_option_register(&cfg_info, "regcontext", ACO_EXACT, bridge_types, NULL, OPT_CHAR_ARRAY_T, 0, CHARFLDSET(struct bridge_profile, regcontext));
 	aco_option_register(&cfg_info, "language", ACO_EXACT, bridge_types, "en", OPT_CHAR_ARRAY_T, 0, CHARFLDSET(struct bridge_profile, language));
 	aco_option_register_custom(&cfg_info, "^sound_", ACO_REGEX, bridge_types, NULL, sound_option_handler, 0);
+	aco_option_register(&cfg_info, "video_update_discard", ACO_EXACT, bridge_types, "2000", OPT_UINT_T, 0, FLDSET(struct bridge_profile, video_update_discard));
 	/* This option should only be used with the CONFBRIDGE dialplan function */
 	aco_option_register_custom(&cfg_info, "template", ACO_EXACT, bridge_types, NULL, bridge_template_handler, 0);
 
diff --git a/apps/confbridge/include/confbridge.h b/apps/confbridge/include/confbridge.h
index cf30d5c62..adf9b867d 100644
--- a/apps/confbridge/include/confbridge.h
+++ b/apps/confbridge/include/confbridge.h
@@ -218,6 +218,7 @@ struct bridge_profile {
 	unsigned int mix_interval;  /*!< The internal mixing interval used by the bridge. When set to 0 the bridgewill use a default interval. */
 	struct bridge_profile_sounds *sounds;
 	char regcontext[AST_MAX_CONTEXT];
+	unsigned int video_update_discard; /*!< Amount of time after sending a video update request that subsequent requests should be discarded */
 };
 
 /*! \brief The structure that represents a conference bridge */