bridging: Add better support for adding/removing streams.

This change adds support to bridge_softmix to allow the addition
and removal of additional video source streams. When such a change
occurs each participant is renegotiated as needed to reflect the
update. If another video source is added then each participant
gets another source. If a video source is removed then it is
removed from each participant. This functionality allows you to
have both your webcam and screenshare providing video if you
desire, or even more streams. Mapping has been changed to use
the topology index on the source channel as a unique identifier
for outgoing participant streams, this will never change and
provides an easy way to establish the mapping.

The bridge_simple and bridge_native_rtp modules have also been
updated to renegotiate when the stream topology of a party changes
allowing the same behavior to occur as added to bridge_softmix.
If a screen share is added then the opposite party is renegotiated.
If that screen share is removed then the opposite party is
renegotiated again.

Some additional fixes are also included in here. Stream state is
now conveyed in SDP so sendonly/recvonly/inactive streams can
be requested. Removed streams now also remove previous state
from themselves so consumers don't get confused.

ASTERISK-28733

Change-Id: I93f41fb41b85646bef71408111c17ccea30cb0c5
This commit is contained in:
Joshua C. Colp
2020-01-05 00:11:20 +00:00
committed by Joshua Colp
parent a6de4497e6
commit 5a5be92b79
8 changed files with 566 additions and 149 deletions

View File

@@ -1823,6 +1823,12 @@ static int create_outgoing_sdp_stream(struct ast_sip_session *session, struct as
} else {
if (session_media->remotely_held) {
attr->name = STR_RECVONLY; /* Remote has sent sendonly, reply recvonly */
} else if (ast_stream_get_state(stream) == AST_STREAM_STATE_SENDONLY) {
attr->name = STR_SENDONLY; /* Stream has requested sendonly */
} else if (ast_stream_get_state(stream) == AST_STREAM_STATE_RECVONLY) {
attr->name = STR_RECVONLY; /* Stream has requested recvonly */
} else if (ast_stream_get_state(stream) == AST_STREAM_STATE_INACTIVE) {
attr->name = STR_INACTIVE; /* Stream has requested inactive */
} else {
attr->name = STR_SENDRECV; /* No hold in either direction */
}

View File

@@ -952,7 +952,7 @@ static int handle_negotiated_sdp(struct ast_sip_session *session, const pjmedia_
{
int i;
struct ast_stream_topology *topology;
unsigned int changed = 0;
unsigned int changed = 0; /* 0 = unchanged, 1 = new source, 2 = new topology */
if (!session->pending_media_state->topology) {
if (session->active_media_state->topology) {
@@ -1064,6 +1064,14 @@ static int handle_negotiated_sdp(struct ast_sip_session *session, const pjmedia_
topology = ast_stream_topology_clone(session->pending_media_state->topology);
if (topology) {
ast_channel_set_stream_topology(session->channel, topology);
/* If this is a remotely done renegotiation that has changed the stream topology notify what is
* currently handling this channel.
*/
if (pjmedia_sdp_neg_was_answer_remote(session->inv_session->neg) == PJ_FALSE &&
session->active_media_state && session->active_media_state->topology &&
!ast_stream_topology_equal(session->active_media_state->topology, topology)) {
changed = 2;
}
}
/* Remove all current file descriptors from the channel */
@@ -1086,10 +1094,12 @@ static int handle_negotiated_sdp(struct ast_sip_session *session, const pjmedia_
ast_channel_unlock(session->channel);
if (changed) {
if (changed == 1) {
struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_STREAM_TOPOLOGY_SOURCE_CHANGED };
ast_queue_frame(session->channel, &f);
} else if (changed == 2) {
ast_channel_stream_topology_changed_externally(session->channel);
} else {
ast_queue_frame(session->channel, &ast_null_frame);
}
@@ -1926,6 +1936,7 @@ static int sdp_requires_deferral(struct ast_sip_session *session, const pjmedia_
enum ast_media_type type;
struct ast_sip_session_media *session_media = NULL;
enum ast_sip_session_sdp_stream_defer res;
pjmedia_sdp_media *remote_stream = sdp->media[i];
/* We need a null-terminated version of the media string */
ast_copy_pj_str(media, &sdp->media[i]->desc.media, sizeof(media));
@@ -1954,6 +1965,25 @@ static int sdp_requires_deferral(struct ast_sip_session *session, const pjmedia_
return -1;
}
/* For backwards compatibility with the core default streams are always sendrecv */
if (!ast_sip_session_is_pending_stream_default(session, stream)) {
if (pjmedia_sdp_media_find_attr2(remote_stream, "sendonly", NULL)) {
/* Stream state reflects our state of a stream, so in the case of
* sendonly and recvonly we store the opposite since that is what ours
* is.
*/
ast_stream_set_state(stream, AST_STREAM_STATE_RECVONLY);
} else if (pjmedia_sdp_media_find_attr2(remote_stream, "recvonly", NULL)) {
ast_stream_set_state(stream, AST_STREAM_STATE_SENDONLY);
} else if (pjmedia_sdp_media_find_attr2(remote_stream, "inactive", NULL)) {
ast_stream_set_state(stream, AST_STREAM_STATE_INACTIVE);
} else {
ast_stream_set_state(stream, AST_STREAM_STATE_SENDRECV);
}
} else {
ast_stream_set_state(stream, AST_STREAM_STATE_SENDRECV);
}
if (session_media->handler) {
handler = session_media->handler;
if (handler->defer_incoming_sdp_stream) {